Read HST_CRF_04_02_03.qxd text version

Back

Print

Directed Reading A (Basic)

To jump to a location in this book 1. Click a bookmark on the left. To print a part of the book 1. Click the Print button. 2. When the Print window opens, type in a range of pages to print. The page numbers are displayed in the bar at the bottom of the document. In the example below, "1 of 151" means that the current page is page 1 in a file of 151 pages.

Back

Print

Name Class Date

Skills Worksheet

Directed Reading A

Section: Asking About Life

1. The study of living things is called

.

IT ALL STARTS WITH A QUESTION

2. The existence of one-celled algae, giant redwood trees, and 40-ton whales

illustrates the amazing

of life.

3. What is one question you could ask about any living thing?

LIFE SCIENTISTS

4. Who can become a life scientist?

5. Where are some of the places that life scientists work?

6. What determines what a life scientist studies?

WHY ASK QUESTIONS?

7. Life scientists are learning about

in order to try to

find a cure for this deadly disease.

8. Studying the way humans inherit the code that controls their cells will help

scientists learn about diseases such as cystic fibrosis, which may be by children from their parents.

9. What is a major cause of many environmental problems?

10. Why are scientists studying the food and habitat needs of Siberian tigers?

Copyright © by Holt, Rinehart and Winston. All rights reserved.

Holt Science and Technology

1

The World of Life Science

Back

Print

Name Class Date

Skills Worksheet

Directed Reading A

Section: Scientific Methods

WHAT ARE SCIENTIFIC METHODS?

1. The first step is using scientific methods is asking questions. Name two steps that follow.

2. Why do scientists vary the order of the steps of scientific methods?

ASK A QUESTION

______ 3. Observations are useful only if they are a. important. b. accurate. c. complicated. d. understood.

FORM A HYPOTHESIS

4. A possible explanation or answer to a question is

a(n)

5. A hypothesis must be

. in order to be useful.

6. A statement of cause and effect that can be used to set up a test for a

hypothesis is called a(n) TEST THE HYPOTHESIS

7. What is a controlled experiment?

.

8. What is a variable?

9. Designing an experiment requires

.

Copyright © by Holt, Rinehart and Winston. All rights reserved.

Holt Science and Technology

2

The World of Life Science

Back

Print

Name Class Date

Directed Reading A continued

10. Why do scientists try to test many individuals?

ANALYZE THE RESULTS

11. How might a scientist organize data in order to analyze them?

DRAW CONCLUSIONS

12. Which is more helpful, proving a hypothesis wrong or supporting a hypothesis? Why?

13. Finding an answer to a question often leads to

.

COMMUNICATE RESULTS

14. What are two reasons that scientists share their results?

Copyright © by Holt, Rinehart and Winston. All rights reserved.

Holt Science and Technology

3

The World of Life Science

Back

Print

Name Class Date

Skills Worksheet

Directed Reading A

Section: Scientific Models

TYPES OF SCIENTIFIC MODELS

______ 1. What is a representation of an object or a system called? a. the real thing c. a model b. a structure d. a prediction ______ 2. Which is an example of a physical model? a. an equation c. a toy rocket b. a microscope d. human bones ______ 3. A Punnett square is an example of a. a physical model. c. a conceptual model. b. a mathematical model. d. a representation of an object. ______ 4. Which of the following is a conceptual model? a. the idea that life originated from chemicals b. a model human skeleton c. x 2 7 d. a plastic human heart

BENEFITS OF MODELS

______ 5. Models can be used to represent things that are a. very small. c. very complicated. b. very large. d. all of the above

BUILDING SCIENTIFIC KNOWLEDGE

6. An explanation that ties together many hypotheses and observations is called

a(n)

. .

7. A scientific idea that rarely changes is a scientific 8. What is the difference between scientific theory and scientific law?

9. New scientific ideas take time to develop into

or to or .

become accepted as

Copyright © by Holt, Rinehart and Winston. All rights reserved.

Holt Science and Technology

4

The World of Life Science

Back

Print

Name Class Date

Skills Worksheet

Directed Reading A

Section: Tools, Measurement, and Safety

1. What do life scientists use tools for?

COMPUTERS AND TECHNOLOGY

2. What is technology?

3. When was the first electronic computer built?

4. How do scientists use computers?

TOOLS FOR SEEING

Match the correct description with the correct term. Write the letter in the space provided.

______ 5. bounces electrons off the surface of a specimen to produce a three-dimensional image

a. magnetic resonance imaging b. scanning electron microscope c. compound light microscope d. transmission electron microscope

______ 6. passes electrons through a specimen to produce a flat image ______ 7. made up of three main parts: a tube with lenses, a stage, and a light ______ 8. sends electromagnetic waves through the body to create images MEASUREMENT

______ 9. Many standardized units of measurement were once based on a. the weather. c. parts of the body. b. mythology. d. ancient worldwide standards.

Copyright © by Holt, Rinehart and Winston. All rights reserved.

Holt Science and Technology

5

The World of Life Science

Back

Print

Name Class Date

Directed Reading A continued

10. What are two advantages of using the International System of Units?

11. What unit of measurement would a life scientist use to describe the length of

an ant?

12. A measure of the surface of an object or region is its

.

13. The units for area are called

units.

14. What is the term used to describe the amount of space something takes up or

the amount of space it contains?

15. What SI units of measurement are used to determine the volume of liquids and solids?

16. A measure of the amount of matter of an object is its

.

17. What units of measurement are used to describe the amount of matter, or mass, in an object?

18. The measurement of how hot or cold something is, and an indication of how

much energy it contains, is its

.

19. What are three different units for measuring temperature?

Copyright © by Holt, Rinehart and Winston. All rights reserved.

Holt Science and Technology

6

The World of Life Science

Back

Print

Name Class Date

Directed Reading A continued

SAFETY RULES!

20. What are two examples of safety precautions you should follow before beginning an experiment?

Match the symbol with the appropriate label, and write the corresponding letter in the space provided.

______21. hand safety ______22. sharp object ______23. clothing protection ______24. chemical safety ______25. eye protection ______26. electric safety ______ 27. plant safety ______28. heating safety ______29. animal safety

a. b. c. d. e. f. g. h. i.

Copyright © by Holt, Rinehart and Winston. All rights reserved.

Holt Science and Technology

7

The World of Life Science

Back

Print

Name Class Date

Skills Worksheet

Directed Reading A

Section: Characteristics of Living Things

LIVING THINGS HAVE CELLS

1. The smallest unit that can perform all life processes is called

a(n)

. .

2. All living things are composed of one or more 3. What covers a cell?

4. What does a cell contain?

5. Describe how the contents of a cell are protected from the cell's environment.

6. In an organism containing many cells, how is the work of the cell performed?

LIVING THINGS SENSE AND RESPOND TO CHANGE

7. Anything in the environment that causes a reaction or change in an organism

is called a(n)

.

Copyright © by Holt, Rinehart and Winston. All rights reserved.

Holt Science and Technology

1

It's Alive!! Or Is It?

Back

Print

Name Class Date

Directed Reading A continued

8. What are three examples of stimuli given in the text?

9. When an organism's outside environment changes, through what process does the organism maintain a stable internal state?

10. Why must an organism maintain stable internal conditions?

11. What is your body trying to do when you are either shivering or sweating?

12. How do some animals control their body temperatures?

Copyright © by Holt, Rinehart and Winston. All rights reserved.

Holt Science and Technology

2

It's Alive!! Or Is It?

Back

Print

Name Class Date

Directed Reading A continued

LIVING THINGS REPRODUCE

13. Two parents produce offspring that share their characteristics

through

reproduction.

14. A single parent produces offspring identical to the parent

through

reproduction.

15. Most single-celled organisms reproduce through

reproduction.

16. Most animals and plants reproduce through

reproduction. LIVING THINGS HAVE DNA ______ 17. What does DNA (deoxyribonucleic acid) do? a. DNA controls the structure and function of cells. b. DNA breaks down food in cells. c. DNA acts as a stimulus in the environment. d. DNA acts as a preservative in foods. ______18. What do organisms pass on to their offspring? a. their cells b. their DNA c. copies of their DNA d. copies of their cells

19. The passing of traits from parents to offspring is

called

.

Copyright © by Holt, Rinehart and Winston. All rights reserved.

Holt Science and Technology

3

It's Alive!! Or Is It?

Back

Print

Name Class Date

Directed Reading A continued

LIVING THINGS USE ENERGY

20. What are three examples of activities of life carried out by all organisms?

21. The total of all chemical activities that an organism performs is an

organism's LIVING THINGS GROW AND DEVELOP

.

22. How does a single-celled organism grow?

23. How do organisms with many cells grow?

24. In addition to getting larger, what other things might happen as living things grow?

Copyright © by Holt, Rinehart and Winston. All rights reserved.

Holt Science and Technology

4

It's Alive!! Or Is It?

Back

Print

Name Class Date

Skills Worksheet

Directed Reading A

Section: The Necessities of Life

1. What are four basic needs of every organism?

WATER ______ 2. Cells of most living things are made of approximately a. 10% water. c. 50% water. b. 33% water. d. 70% water. ______ 3. Most of the chemical reactions involved in metabolism require a. air. c. water. b. oxygen. d. carbon dioxide.

4. About how long can humans survive without water?

AIR ______ 5. Air is a mixture of gases, including oxygen and a. carbon monoxide. b. carbon dioxide. c. sulfur dioxide. d. nitrogen dioxide. ______ 6. What is a chemical process in which most living things use oxygen? a. releasing energy from food b. storing energy c. transporting waste d. breaking down cells ______ 7. Green plants, algae, and some bacteria need carbon dioxide gas in addition to a. carbohydrates. b. lipids. c. sugar. d. oxygen.

Copyright © by Holt, Rinehart and Winston. All rights reserved.

Holt Science and Technology

5

It's Alive!! Or Is It?

Back

Print

Name Class Date

Directed Reading A continued

8. Green organisms convert the energy in sunlight to energy stored in

food during A PLACE TO LIVE

.

9. What do organisms need in the place where they live?

10. How does the limited amount of space on Earth affect organisms?

FOOD

11. What are two things food gives organisms?

12. What are two ways organisms use nutrients from food?

Organisms are grouped by how they get their food. The three groups are producers, consumers, and decomposers. In the space provided, write P if the phrase describes a producer, C if the phrase describes a consumer, and D if the phrase describes a decomposer.

______13. eats other living organisms or organic matter ______14. a mushroom ______15. a frog ______16. uses energy from the sun or the chemicals in the environment to make food ______ 17. a plant ______18. gets energy by breaking down nutrients in dead organisms or animal wastes

Copyright © by Holt, Rinehart and Winston. All rights reserved.

Holt Science and Technology

6

It's Alive!! Or Is It?

Back

Print

Name Class Date

Directed Reading A continued

PUTTING IT ALL TOGETHER

19. What do all organisms do to food in order to use the nutrients in it?

20. Nutrients are made up of

, a substance

created when two or more atoms combine.

21. Molecules made of different kinds of atoms are

called

.

22. Chemical elements within molecules combine to form building blocks of cells. Name the five chemical building blocks of cells.

PROTEINS

Match the correct definition with the correct term. Write the letter in the space provided.

______23. compounds that make up proteins ______24. proteins that speed up chemical reactions ______25. a protein found in red blood cells that attaches to oxygen ______26. a nutrient involved in almost all life processes CARBOHYDRATES

a. enzymes b. protein c. amino acids d. hemoglobin

27. Energy-giving nutrients such as sugars, starches, and fiber are

called

28. How do cells use carbohydrates?

.

Copyright © by Holt, Rinehart and Winston. All rights reserved.

Holt Science and Technology

7

It's Alive!! Or Is It?

Back

Print

Name Class Date

Directed Reading A continued

29. Carbohydrates made of one sugar molecule or a few linked sugar molecules

are called

.

30. What is an example of a simple carbohydrate?

31. A carbohydrate made of hundreds of molecules linked together is called

a(n)

.

32. In terms of carbohydrates, what are you eating when you eat mashed potatoes?

LIPIDS ______33. Which of the following is NOT true of lipids? a. Lipids mix with water. b. Lipids store energy. c. Lipids include fats and oils. d. Lipids make up cell membranes.

34. The molecules that form much of the cell membrane

are

.

35. Where can an organism get energy once it has used up most of its carbohydrates?

36. What is a difference between fats and oils?

Copyright © by Holt, Rinehart and Winston. All rights reserved.

Holt Science and Technology

8

It's Alive!! Or Is It?

Back

Print

Name Class Date

Directed Reading A continued

ATP

37. The major energy-carrying molecule in the cell is _______________________. 38. How do cells get energy from carbohydrates and lipids?

NUCLEIC ACIDS

39. Molecules consisting of subunits called nucleotides are

called

.

40. Why are nucleic acids called the blueprints of life?

Copyright © by Holt, Rinehart and Winston. All rights reserved.

Holt Science and Technology

9

It's Alive!! Or Is It?

Back

Print

Name Class Date

Skills Worksheet

Directed Reading A

Section: The Diversity of Cells

1. The smallest unit that can perform all the processes necessary for life is

a(n) CELLS AND THE CELL THEORY

.

Match the correct description with the correct name. Write the letter in the space provided.

______ 2. He was the first person to describe cells. ______ 3. He discovered single-celled organisms including bacteria. ______ 4. He concluded that all plant parts were made of cells. ______ 5. He concluded that all animal tissues were made of cells. ______ 6. He concluded that all cells come from existing cells. CELL SIZE ______ 7. Why can a chicken egg grow so large? a. It is a single cell. b. It has a yolk and a shell. c. It does not have to take in nutrients. d. It grows faster than small cells. ______ 8. What limits most cells to a very small size? a. the surface area­to-volume ratio of the cell b. the thickness of the cell membrane c. the amount of cytoplasm in the cell d. the number of surrounding cells

a. Schleiden b. Virchow c. Hooke d. Leeuwenhoek e. Schwann

______ 9. How would you calculate the surface area­to-volume ratio? a. Divide the volume by the surface area. b. Divide the total surface area of the cell by the cell's volume. c. Multiply the area of each side times the number of sides. d. Multiply the surface area times the volume.

Copyright © by Holt, Rinehart and Winston. All rights reserved.

Holt Science and Technology

1

Cells: The Basic Units of Life

Back

Print

Name Class Date

Directed Reading A continued

10. What are the three parts of the cell theory?

11. What kind of cells have cell walls?

PARTS OF A CELL

Match the correct description with the correct term. Write the letter in the space provided.

______12. a protective layer that covers a cell's surface ______13. the fluid inside a cell ______14. a structure that performs a specific function in the cells ______15. the genetic material that carries information needed to make new cells or new organisms ______16. an organelle that contains DNA and has a role in growth, metabolism, and reproduction TWO KINDS OF CELLS

17. What parts do all cells have in common?

a. DNA b. cell membrane c. nucleus d. organelle e. cytoplasm

18. What are the two basic kinds of cells?

PROKARYOTES: EUBACTERIA AND ARCHAEBACTERIA

19. What are prokaryotes?

Copyright © by Holt, Rinehart and Winston. All rights reserved.

Holt Science and Technology

2

Cells: The Basic Units of Life

Back

Print

Name Class Date

Directed Reading A continued

20. What are the most common prokaryotes (and the smallest cells)?

21. What are ribosomes?

22. How do eubacteria and archaebacteria differ?

23. What are three types of archaebacteria?

EUKARYOTIC CELLS AND EUKARYOTES ______24. How do eukaryotes compare in size to prokaryotes? a. Eukaryotes have more cells. b. They are about the same size. c. Eukaryotes are about 10 times smaller. d. Eukaryotes are about 10 times larger. ______25. What does a eukaryote have that a prokaryote does not? a. one or more cells b. cells with a nucleus c. cells with DNA d. cells with membranes ______26. Which of these words describes humans? a. eukaryote b. prokaryote c. protist d. fungus

27. What does "multicellular" mean?

Copyright © by Holt, Rinehart and Winston. All rights reserved.

Holt Science and Technology

3

Cells: The Basic Units of Life

Back

Print

Name Class Date

Skills Worksheet

Directed Reading A

Section: Eukaryotic Cells

CELL WALL

1. What is the function of a cell wall?

2. What are the cell walls of plants and algae made of?

3. What are the cell walls of fungi made of?

CELL MEMBRANE

4. What is a cell membrane?

5. What are three types of compounds contained in the cell membrane?

6. What two substances control the movement of materials into and out of the cell?

CYTOSKELETON ______ 7. A web of proteins in the cytoplasm is known as the a. phospholipid. c. cell membrane. b. cytoskeleton. d. organelle.

8. What are the two functions of the cytoskeleton?

Copyright © by Holt, Rinehart and Winston. All rights reserved.

Holt Science and Technology

4

Cells: The Basic Units of Life

Back

Print

Name Class Date

Directed Reading A continued

NUCLEUS ______ 9. What is the genetic material contained inside a cell's nucleus? a. protein c. DNA b. lipids d. nucleolis ______10. The function of proteins in a cell is to a. control chemical reactions. c. cover the nucleus. b. store genetic information. d. copy messages from DNA. ______11. What is the nucleolus? a. the opposite of the nucleus b. another name for DNA c. a network of fibers in the cytoplasm d. a dark area of the nucleus that stores materials and makes ribosomes RIBOSOMES

12. Organelles that make proteins are called 13. Proteins are made of

. .

ENDOPLASMIC RETICULUM

14. A system of folded membranes in which proteins, lipids and other materials

are made is the

15. Two forms of endoplasmic reticulum are

.

and MITOCHONDRIA

.

______16. What function does a mitochondrion perform? a. It breaks down sugar to produce energy. b. It makes proteins. c. It breaks down toxic materials. d. It stores material used to make ribosomes.

17. The site of cellular respiration is the

.

18. Energy produced in mitochondria is stored in a substance called

.

Copyright © by Holt, Rinehart and Winston. All rights reserved.

Holt Science and Technology

5

Cells: The Basic Units of Life

Back

Print

Name Class Date

Directed Reading A continued

CHLOROPLASTS ______19. Chloroplasts are organelles that are found in the cells of a. animals. c. mitochondria. b. plants and algae. d. all eukaryotic cells. ______20. Which process happens inside a chloroplast? a. production of ATP c. photosynthesis b. production of DNA d. formation of animal cells ______21. Chloroplasts are green because they contain a. sugar. c. chlorophyll. b. proteins. d. DNA. GOLGI COMPLEX ______22. The function of the Golgi complex is to a. produce sugar and water. b. package and deliver proteins. c. produce oxygen. d. trap energy from the sun. CELL COMPARTMENTS

23. A small sac that surrounds material to be moved into or out of a cell

is a(n) CELLULAR DIGESTION

24. What is a lysosome?

.

25. What is the function of lysosomes?

26. What function do vacuoles perform in plant and fungal cells?

Copyright © by Holt, Rinehart and Winston. All rights reserved.

Holt Science and Technology

6

Cells: The Basic Units of Life

Back

Print

Name Class Date

Skills Worksheet

Directed Reading A

Section: The Organization of Living Things

THE BENEFITS OF BEING MULTICELLULAR

1. How do multicellular organisms grow?

2. What are three benefits of being multicellular?

CELLS WORKING TOGETHER

3. What is a tissue?

4. What are four basic types of tissues in animals?

5. What are three basic types of tissues in plants?

TISSUES WORKING TOGETHER

6. A structure that is made up of two or more tissues working together is

called a(n) ORGANS WORKING TOGETHER

.

7. A group of organs working together to perform a particular function is

called a(n)

.

Copyright © by Holt, Rinehart and Winston. All rights reserved.

Holt Science and Technology

7

Cells: The Basic Units of Life

Back

Print

Name Class Date

Directed Reading A continued

8. What are examples of plant organs?

ORGANISMS ______ 9. Anything that can perform life processes is a. a cell. b. an organ system. c. a tissue. d. an organism. ______10. The term for any organism with only one cell is a. protist. b. unicellular. c. specialized. d. bacteria. ______11. Which of these is the lowest level of organization? a. cells b. tissues c. organs d. systems ______12. Which of these is the highest level of organization? a. cells b. tissues c. organs d. organ systems STRUCTURE AND FUNCTION

13. The arrangement of parts in an organism is the 14. The job the part does within the organism is the 15. The millions of tiny air sacs in the lungs are called

. . .

Copyright © by Holt, Rinehart and Winston. All rights reserved.

Holt Science and Technology

8

Cells: The Basic Units of Life

Back

Print

Name Class Date

Skills Worksheet

Directed Reading A

Section: Exchange with the Environment

1. How is an organism's cell like a factory?

WHAT IS DIFFUSION?

2. The movement of particles from areas of high concentration to areas of low

concentration is called

.

3. The fluids that surround and fill a cell are made mostly of

.

4. Water is made up of particles called 5. The diffusion of water through a semipermeable membrane is

.

called

6. What is the result of osmosis?

.

7. What process is important to cell functions?

8. Describe what would happen if you put red blood cells into a salty solution.

9. Describe the effect of osmosis on a wilted plant that has been watered.

Copyright © by Holt, Rinehart and Winston. All rights reserved.

Holt Science and Technology

1

The Cell in Action

Back

Print

Name Class Date

Directed Reading A continued

MOVING SMALL PARTICLES

Match the correct description with the correct term. Write the letter in the space provided.

______10. particles moving across a cell membrane without using energy

a. channels b. active transport c. passive transport d. diffusion and osmosis e. energy

______11. passageways in a cell membrane ______12. the movement of particles from an area of low to an area of high concentration across a cell membrane ______13. two examples of passive transport ______14. a cell needs this to transport particles by active transport

15. The channels in a cell membrane are made up of

.

MOVING LARGE PARTICLES

16. A large particle can enter a cell using a process

called

.

17. What happens to a cell during the process of endocytosis?

18. A large particle can leave a cell using a process

called

.

19. What happens to a cell during the process of exocytosis?

Copyright © by Holt, Rinehart and Winston. All rights reserved.

Holt Science and Technology

2

The Cell in Action

Back

Print

Name Class Date

Directed Reading A continued

Use the figures below to answer questions 20 and 21.

20. In which order would the figures demonstrate exocytosis?

21. In which order would the figures demonstrate endocytosis?

Copyright © by Holt, Rinehart and Winston. All rights reserved.

Holt Science and Technology

3

The Cell in Action

Back

Print

Name Class Date

Skills Worksheet

Directed Reading A

Section: Cell Energy

1. What is your body telling you when you feel hungry?

2. Where do plant cells get their energy? ___________________________________

3. Where do many animal cells get the energy they need?

FROM SUN TO CELL ______ 4. Where does almost all of the energy that fuels life come from? a. the Earth c. plants b. gasoline d. the sun

5. Plants are able to change the sun's energy into food through the process

of

.

6. The molecules in plant cells that absorb light energy are called

.

7. Plants get their green color from 8. What is glucose?

.

9. Explain why glucose is important to a plant cell.

10. Photosynthesis produces

and .

Copyright © by Holt, Rinehart and Winston. All rights reserved.

Holt Science and Technology

4

The Cell in Action

Back

Print

Name Class Date

Directed Reading A continued

GETTING ENERGY FROM FOOD

11. Cells use

to break down food.

12. Many cells are able to get energy without using oxygen through a process

called

.

13. Why is breathing important to many organisms?

14. Describe what takes place during cellular respiration in complex organisms.

15. What does your body do with the energy released during cellular respiration?

16. Adenosine triphosphate, also called ATP, is formed during cellular

respiration. ATP supplies

that fuels cell activities.

17. Cellular respiration in the cells of eukaryotes takes place in

inside the cell.

18. During photosynthesis, plant cells take in carbon dioxide, CO2, and release oxygen, O2. How is this different from cellular respiration?

19. Why do you get a burning sensation in your muscles during strenuous exercise?

Copyright © by Holt, Rinehart and Winston. All rights reserved.

Holt Science and Technology

5

The Cell in Action

Back

Print

Name Class Date

Directed Reading A continued

20. What is another kind of fermentation?

21. How does the process of fermentation help bread rise?

Match the correct description with the correct term. Write the letter in the space provided.

______22. this occurs when cells use oxygen to produce energy from food ______23. the breakdown of food without using oxygen ______24. this forms carbon dioxide, CO2, during fermentation and is used to help bread rise. ______25. this is converted into food by the process of photosynthesis ______26. this is released during photosynthesis, cells take in CO2 ______ 27. this is released by cells during cellular respiration

a. oxygen b. yeast c. the sun's energy d. cellular respiration e. water, carbon dioxide, and energy f. fermentation

Copyright © by Holt, Rinehart and Winston. All rights reserved.

Holt Science and Technology

6

The Cell in Action

Back

Print

Name Class Date

Skills Worksheet

Directed Reading A

Section: The Cell Cycle

1. Why is it important for your body to produce millions of new cells by the time you finish reading this sentence?

THE LIFE OF A CELL ______ 2. When does the cell cycle begin? a. when the cell is formed b. when the cell divides c. when the cell uses energy d. when the cell takes in oxygen ______ 3. When does the cell cycle end? a. when the cell is formed b. when the cell divides and makes new cells c. when the cell uses energy d. when the cell takes in oxygen

4. What must a cell do before it can divide to make a new cell?

5. What makes sure that each new cell will be an exact copy of its parent cell?

6. A cell without a nucleus is a(n) 7. A cell with a nucleus is a(n) 8. A chromosome is the main ring of DNA in a(n)

cell. cell.

cell.

9. A chromosome is made up of DNA and protein in a(n)

cell.

Copyright © by Holt, Rinehart and Winston. All rights reserved.

Holt Science and Technology

7

The Cell in Action

Back

Print

Name Class Date

Directed Reading A continued

10. Are bacteria prokaryotic cells or eukaryotic cells?

11. Bacteria create new cells through a kind of cell division called

.

12. When binary fission is complete, the results are two cells that each contain

one copy of

.

13. The chromosomes of eukaryotic cells have more

than do the chromosomes of prokaryotic cells.

14. Humans have

chromosomes, while fruit flies have . Potatoes have

only chromosomes.

15. Chromosomes line up into pairs called 16. What do pairs of homologous chromosomes have in common?

.

17. In the beginning of the eukaryotic cell cycle, the cell grows and duplicates

its

and

.

18. After a chromosome is duplicated, the two copies are

called

.

19. Chromatids in eukaryotic cells separate during a process called

.

20. Where are chromatids held together?

Copyright © by Holt, Rinehart and Winston. All rights reserved.

Holt Science and Technology

8

The Cell in Action

Back

Print

Name Class Date

Directed Reading A continued

21. Describe what happens during the first stage of the cell cycle in a eukaryotic cell.

22. Describe what happens during the second stage of the cell cycle in a eukaryotic cell.

23. Describe what happens during the third stage of the cell cycle in a eukaryotic cell.

MITOSIS AND THE CELL CYCLE ______24. Before mitosis begins, what paired cell structures are copied? a. the cell plates b. the chromosomes c. the cell membranes d. the nuclear membrane

Copyright © by Holt, Rinehart and Winston. All rights reserved.

Holt Science and Technology

9

The Cell in Action

Back

Print

Name Class Date

Directed Reading A continued

Use the diagram below to help answer questions 25-30, which describe the phases of the cell cycle. Write the correct phase in each blank, using "Interphase," "Mitosis Phase 1," "Mitosis Phase 2," "Mitosis Phase 3," or "Mitosis Phase 4," or "Cytokinesis."

Interphase

Mitosis Phase 1

Mitosis Phase 2

Mitosis Phase 3

Mitosis Phase 4

Cytokinesis

_______________________ 25. Chromatids separate and move to opposite sides of the cell. _______________________ 26. The chromosomes line up along the equator of the cell. _______________________ 27. Before mitosis begins, chromosomes are copied. _______________________ 28. The nuclear membrane forms around the two sets of chromosomes, and the chromosomes unwind. Mitosis is complete. _______________________ 29. Mitosis begins. The nuclear membrane dissolves. Chromosomes condense into rodlike structures. _______________________ 30. In cells that lack a cell wall, the cell pinches in two. In cells that have a cell wall, a cell plate forms between the two new cells.

Copyright © by Holt, Rinehart and Winston. All rights reserved.

Holt Science and Technology

10

The Cell in Action

Back

Print

Name Class Date

Directed Reading A continued

31. Describe how animal cells and eukaryotes without cell walls divide their cytoplasm during cytokinesis..

Place the following structures in the order in which they form in eukaryotic cells with cell walls during cytokinesis. Write the appropriate number in the space provided.

______32. cell wall ______33. cell plate ______34. cell membrane

Copyright © by Holt, Rinehart and Winston. All rights reserved.

Holt Science and Technology

11

The Cell in Action

Back

Print

Name Class Date

Skills Worksheet

Directed Reading A

Section: Mendel and His Peas

1. What is heredity?

2. Give one example of something about yourself that has to do with heredity.

WHO WAS GREGOR MENDEL? ______ 3. Gregor Mendel was born in a. the United States. b. Austria. ______ 4. Gregor Mendel did his research a. in a laboratory. b. at a university. c. at a monastery. d. on a farm. UNRAVELING THE MYSTERY ______ 5. In Mendel's work, first and second generation mean a. parents and offspring. b. plants and animals. c. peas and peapods. d. one kind of organism.

6. Both male and female reproductive structures are found in c. Germany. d. Italy.

plants.

7. The offspring of

plants all have the same traits

as the parent.

8. Because pea plants can

, one plant is able to

fertilize another.

Copyright © by Holt, Rinehart and Winston. All rights reserved.

Holt Science and Technology

1

Heredity

Back

Print

Name Class Date

Directed Reading A continued

9. List two ways that a plant can cross-pollinate.

10. Peas can both cross-pollinate and self-pollinate. Why was this a key factor in Mendel's work?

11. In a population, a(n)

is a feature that has different .

forms.

12. Different forms of characteristics are called 13. Why was it important to Mendel's work that peas were true breeding?

14. How did Mendel make sure that some plants cross-pollinated?

Copyright © by Holt, Rinehart and Winston. All rights reserved.

Holt Science and Technology

2

Heredity

Back

Print

Name Class Date

Directed Reading A continued

MENDEL'S FIRST EXPERIMENTS

Match the correct definition with the correct term. Write the letter in the space provided.

______15. seen in the second generation ______16. offspring from the first cross ______ 17. seen in the first generation MENDEL'S SECOND EXPERIMENTS

a. dominant trait b. first-generation plants c. recessive trait

______18. What results did Mendel get when he allowed the first-generation plants to self-pollinate? a. half purple and half white offspring b. every fourth plant had white flowers c. every fourth plant had purple flowers d. offspring with all purple flowers ______19. When a relationship between two different things is shown in a fraction, it is a. a ratio. c. a dominant trait b. a problem. d. a recessive trait. ______20. Gregor Mendel realized the only explanation for his results was that a. the traits were appearing at random. b. the male traits were always the dominant ones. c. each trait had two sets of instructions, one from each parent. d. his important research would open the door to modern genetics. ______21. Mendel was recognized for his discovery a. five years after he finished his work. b. in 1865 when he published his work. c. about ten years ago. d. more than 30 years later.

Copyright © by Holt, Rinehart and Winston. All rights reserved.

Holt Science and Technology

3

Heredity

Back

Print

Name Class Date

Skills Worksheet

Directed Reading A

Section: Traits and Inheritance

______ 1. What ratio did Mendel find for dominant to recessive traits? a. 1 to 1 b. 2 to 1 c. 3 to 1 d. 4 to 1 A GREAT IDEA ______ 2. What are the instructions for an inherited trait? a. alleles b. phenotype c. albinism d. genes ______ 3. Two forms of a gene, one from each parent, are called a. alleles. b. phenotypes. c. albinism. d. genes. ______ 4. When gene pairs are written, the dominant allele has a(n) a. D in front of it. b. capital letter. c. bold letter. d. underlined letter. ______ 5. The genotype Pp can also be written a. pP b. pp c. PP d. Ppp ______ 6. When purple is dominant, the white offspring of purple and white parents will be a. pP b. pp c. PP d. Ppp

Copyright © by Holt, Rinehart and Winston. All rights reserved.

Holt Science and Technology

4

Heredity

Back

Print

Name Class Date

Directed Reading A continued

Match the correct description with the correct term. Write the letter in the space provided.

______ 7. used to organize possible offspring combinations ______ 8. an organism's appearance ______ 9. a plant with one dominant and one recessive gene ______10. condition that causes colorless hair, skin, and eyes ______11. a plant with either two dominant or two recessive genes ______12. genetic makeup formed from both inherited alleles together ______13. instructions for traits passed to offspring from parents p P P Pp Pp p Pp Pp P p P PP pP

a. phenotype b. heterozygous c. genotype d. homozygous e. genes f. albinism g. Punnett square

p Pp pp

14. Look at the Punnett square on the left. What genotype do the offspring have?

15. Look at the Punnett square on the left. What will happen to the recessive allele?

16. Look at the Punnett square on the right. Which genotypes contain a dominant allele?

17. Look at the Punnett square on the right. Which two genotypes are exactly the same?

Copyright © by Holt, Rinehart and Winston. All rights reserved.

Holt Science and Technology

5

Heredity

Back

Print

Name Class Date

Directed Reading A continued

WHAT ARE THE CHANCES?

______18. The mathematical chance that something can happen is called a. genotype. b. albinism. c. probability. d. trait. 19. What is the probability of inheriting two p alleles?

20. Why are the traits that Mendel studied in pea plants easy to predict?

MORE ABOUT TRAITS

21. When each allele has its own degree of influence, it is known as

.

22. How is a snapdragon an example of incomplete dominance?

23. Sometimes one gene can influence more than one 24. Besides genes, what else can have an influence on traits?

.

Copyright © by Holt, Rinehart and Winston. All rights reserved.

Holt Science and Technology

6

Heredity

Back

Print

Name Class Date

Skills Worksheet

Directed Reading A

Section: Meiosis

______ 1. What are two kinds of reproduction? a. chromosomes and offspring b. heredity and genes c. asexual and sexual d. mothers and fathers

ASEXUAL REPRODUCTION ______ 2. What is the name for the way cells divide in asexual reproduction? a. twins b. mitosis c. meiosis d. homologous

3. How many parent cells are needed in asexual reproduction?

SEXUAL REPRODUCTION ______ 4. When two parent cells join together to form offspring, it is called a. asexual reproduction. b. mitosis. c. sexual reproduction d. meiosis. ______ 5. Parent cells are called a. sex cells. b. body cells. c. homologous cells. d. allele cells. ______ 6. Chromosomes that carry the same sets of genes are called a. twin chromosomes. b. homologous chromosomes. c. ordinary chromosomes. d. asexual chromosomes. ______ 7. How do sex cells differ from other human cells? a. Sex cells have more chromosomes. b. Sex cells have half as many chromosomes. c. Sex cells are larger. d. Sex cells have 46 pairs of chromosomes.

Copyright © by Holt, Rinehart and Winston. All rights reserved.

Holt Science and Technology

7

Heredity

Back

Print

Name Class Date

Directed Reading A continued

8. Sex cells are made during a process called

.

9. In humans, when a new cell is formed from a sperm cell and an egg cell, how many chromosomes does it have?

10. Walter Sutton's important observation was that chromosomes of the eggs and

sperm cells are located inside the

11. Sutton proposed that 12. When a sex cell divides, what is the result?

. are located on chromosomes.

THE STEPS OF MEIOSIS

Match the correct definition with the correct term. Write the letter in the space provided.

13. how chromosomes look before meiosis 14. exact duplicate of a chromosome 15. forms around each new cell during meiosis 16. process in which the nucleus divides only once

a. chromatid b. cell membrane c. threadlike d. mitosis

Put the eight steps of meiosis in order from first to last. Write the appropriate number in the space provided.

______ 17. The chromosomes separate from their partners and move to opposite ends of the cell. ______18. The chromosomes are not copied again between the two cell divisions. ______19. Four new cells have formed from the original single cell. ______20. Each chromosome makes an exact copy of itself. ______21. The chromatids pull apart, and the cells divide. ______22. The nuclear membrane re-forms, and the cell divides. ______23. The chromosomes line up at the equator of each cell. ______24. Similar chromosomes pair with one another.

Copyright © by Holt, Rinehart and Winston. All rights reserved.

Holt Science and Technology

8

Heredity

Back

Print

Name Class Date

Directed Reading A continued

25. After meiosis, how many chromosomes does each new cell have?

MEIOSIS AND MENDEL

26. The steps in

explain Mendel's results.

27. When two true-breeding plants are crossed, only one

is possible.

28. The genes that determine sex are found on the 29. In humans, what kind of sex chromosomes do females have?

.

30. In humans, what kind of sex chromosomes do males have?

31. Which chromosome from the sperm is necessary to produce a female?

32. Which chromosome from the sperm is necessary to produce a male?

33. Because males have only one X chromosome, what is more likely to happen to them?

34. Name two sex-linked disorders.

35. To trace a trait through generations of a family, you can use

a(n)

.

36. A genetic counselor can often predict if a person is

a(n)

of hereditary diseases. alleles.

37. People with cystic fibrosis have two

38. When organisms with desirable characteristics are mated by humans, it is

called

.

Copyright © by Holt, Rinehart and Winston. All rights reserved.

Holt Science and Technology

9

Heredity

Back

Print

Name Class Date

Skills Worksheet

Directed Reading A

Section: What Does DNA Look Like?

______ 1. What are chromosomes made of? a. inherited characteristics c. cells and structures b. generations d. protein and DNA ______ 2. What is the name of the material that determines inherited characteristics? a. deoxyribonucleic acid c. RNA b. ribosome d. amino acid

THE PIECES OF THE PUZZLE

3. The subunits that make up DNA are called a. phosphates. c. amino acids. b. nucleotides. d. bases. 4. What two things must DNA be able to do?

5. Why must DNA be able to be copied?

6. Scientists were surprised about how much the DNA molecule could do,

because they thought only give instructions and be copied during cell division.

7. What three things is a nucleotide made of?

molecules could

8. What are the four bases of a nucleotide?

Copyright © by Holt, Rinehart and Winston. All rights reserved.

Holt Science and Technology

1

Genes and DNA

Back

Print

Name Class Date

Directed Reading A continued

9. What four letters stand for the four types of bases?

10. According to Chargaff's rules, the amount of

always equals the amount of thymine.

11. According to Chargaff's rules, the amount of guanine always

equals the amount of

12. Rosalind Franklin used a process known as

. to

make images of DNA molecules.

13. What shape did Franklin's images show?

14. What did James Watson and Francis Crick's model of DNA look like?

15. What two things did this model eventually help explain?

DNA'S DOUBLE STRUCTURE

16. The twisted ladder shape of DNA is called a(n) 17. What molecules form the sides of the ladder?

.

18. What are the rungs of the DNA ladder made of?

Copyright © by Holt, Rinehart and Winston. All rights reserved.

Holt Science and Technology

2

Genes and DNA

Back

Print

Name Class Date

Directed Reading A continued

Match the correct description with the correct term. Write the letter in the space provided.

______19. Pairs with adenine ______20. Pairs with guanine

a. cytosine b. thymine

21. How did the double helix structure match Chargaff's observations?

MAKING COPIES OF DNA

22. The pairing of bases allows the cell to

, or make

copies of DNA.

23. Both sides of a DNA molecule are

, binding only

with their match.

24. Where is a molecule split during replication?

25. After a DNA molecule splits, what is added to each side of the ladder?

26. How often is DNA copied?

27. What in the cell helps with unwinding, copying, and rewinding the DNA?

Copyright © by Holt, Rinehart and Winston. All rights reserved.

Holt Science and Technology

3

Genes and DNA

Back

Print

Name Class Date

Skills Worksheet

Directed Reading A

Section: How DNA Works

1. How much DNA does a single cell in your body hold?

UNRAVELING DNA

______ 2. What shape does DNA take in a cell that lacks a nucleus? a. a loose loop c. a tight chain b. a structure d. a protein ______ 3. What are strands of DNA bundled into in a cell with a nucleus called? a. nucleotides c. chromosomes b. loose loops d. tight chains 4. A string of nucleotides that give the cell information about a certain trait is

known as a(n)

5. About how many genes do humans have?

.

6. How many chromosomes does a human cell have before division?

7. When a cell is ready to divide, how many chromatids make up a chromosome?

GENES AND PROTEINS

8. The

code is read like a book. . . . .

9. The alphabet of the code is made of the 10. Groups of three bases are the codes for specific 11. A long string of amino acids forms a(n) 12. Instructions for making a protein are given by each

Copyright © by Holt, Rinehart and Winston. All rights reserved.

Holt Science and Technology

4

Genes and DNA

Back

Print

Name Class Date

Directed Reading A continued

13. List two examples of things proteins help determine about you.

14. Several forms of RNA or

help change DNA code

into proteins.

15. Because it is so similar to

, RNA can serve as a

temporary copy of a DNA sequence.

16. The "factory" that assembles proteins is known as

a(n)

. moves from the

17. A mirror-like copy of DNA called

nucleus to the ribosome.

18. Another form of RNA called

matches amino acids

with the bases on the messenger RNA.

Put the following steps in making a protein in order by putting a number in the space provided: 1 for step 1, 2 for step 2, etc.

______19. The RNA copy is fed through the ribosome. ______20. Transfer RNA molecules deliver amino acids to the ribosome. ______21. Transfer RNA molecules pick up amino acids from the cytoplasm. ______22. The amino acids are joined to make a protein. ______23. A mirrorlike copy of the gene is made of RNA.

Copyright © by Holt, Rinehart and Winston. All rights reserved.

Holt Science and Technology

5

Genes and DNA

Back

Print

Name Class Date

Directed Reading A continued

CHANGES IN GENES

24. Changes in the number, type, or order of bases on a piece of DNA are

known as

.

Match the correct definition with the correct term. Write the letter in the space provided.

______25. A base pair is added

a. substitution b. insertion c. deletion

______26. A base pair is replaced ______ 27. A base pair is removed

28. Physical or chemical agents known as

can cause

mutations in DNA.

29. List two examples of mutagens.

AN EXAMPLE OF A SUBSTITUTION ______30. Sickle cell anemia is caused by a a. substitution mutation. b. deletion mutation. USES OF GENETIC KNOWLEDGE ______31. The manipulation of individual genes within organisms by scientists is called a. mutation. c. genetic property. b. drug enhancement. d. genetic engineering.

32. List two possible uses of genetic engineering. c. insertion mutation. d. blood vessel mutation.

33. Because DNA is unique, DNA

can identify the

unique patterns in an individual's DNA and help solve crimes.

34. Only identical twins have truly identical

.

35. A scientifically created organism that has an exact copy of another organism's

genes is a(n)

.

Copyright © by Holt, Rinehart and Winston. All rights reserved.

Holt Science and Technology

6

Genes and DNA

Back

Print

Name Class Date

Skills Worksheet

Directed Reading A

Section: Change Over Time

1. One way to tell kinds of animals apart is by their

.

DIFFERENCES AMONG ORGANISMS ______ 2. How does adaptation help an organism? a. It helps the organism change colors. b. It improves its ability to survive and reproduce. c. It improves its ability to change species. d. It helps the organism become a fossil. ______ 3. If one animal or plant has the same characteristics as another, they may both be part of the same a. evolution. c. species. b. planet. d. fossil record.

4. Two organisms that can mate to produce offspring that can reproduce belong

to the same

.

5. When members of the same species live in the same place, they form

a(n)

. have vanished and

6. Since life began on Earth, many

many new ones have appeared.

7. Scientists have observed that species 8. The inherited

over time. in populations also change

over time.

9. What can result as populations of organisms change?

10. The process by which new species gradually develop is called

. EVIDENCE OF CHANGES OVER TIME ______11. Where do scientists look for evidence of evolution? a. in the layers of the Earth c. in water b. in caves d. in old books

Copyright © by Holt, Rinehart and Winston. All rights reserved.

Holt Science and Technology

1

The Evolution of Living Things

Back

Print

Name Class Date

Directed Reading A continued

______12. What is a fossil? a. a layer of sediment b. a living organism c. a very old organism d. remains of a once-living organism

13. Describe how a fossil is usually formed.

14. What is the timeline of life formed by studying fossils called?

15. How are fossils organized in the fossil record?

16. Fossils in newer layers of the Earth tend to resemble

current

.

17. In older layers of the Earth, are fossils more or less likely to resemble today's animals or plants?

18. Some fossils may be of earlier life-forms that do not

anymore. EVIDENCE OF ANCESTRY ______19. The fossil record provides evidence about a. the age of rocks. b. the order in which species have existed. c. the number of layers the Earth has. d. the composition of minerals. ______20. All living things inherit similar traits from their a. ancestors. c. fossils. b. evolution. d. descendants.

Copyright © by Holt, Rinehart and Winston. All rights reserved.

Holt Science and Technology

2

The Evolution of Living Things

Back

Print

Name Class Date

Directed Reading A continued

21. As scientists study the fossil record, they may draw models to illustrate their

about the relationships between extinct and living organisms.

22. How is a new species or group of species represented in the scientist's model?

23. List two groups of animals that may share a common ancestor with whales.

24. Scientists think that all mammal species alive today evolved from

common

.

25. Scientists have combined information on hundreds of thousands of organisms

to sketch out a

that includes all known organisms.

26. What does the lack of a fossil record for some of the Earth's history mean to scientists?

EXAMINING ORGANISMS

27. In addition to fossils, how can scientists learn about an organism's ancestors?

28. List three things about whales that tell scientists that they are not fish.

29. What does a whale body have that hints it had an ancestor that lived on land?

30. What evidence did scientists find that ancient land mammals evolved into modern whales?

Copyright © by Holt, Rinehart and Winston. All rights reserved.

Holt Science and Technology

3

The Evolution of Living Things

Back

Print

Name Class Date

Directed Reading A continued

COMPARING ORGANISMS ______31. If you compared two kinds of living organisms, what might you learn about their history? a. how long ago they evolved b. whether they share a common ancestor c. whether they live in the same place d. whether they could mate and reproduce ______32. What do organisms inherit from ancestors? a. mammal characteristics c. hind limbs b. traits and DNA d. new traits ______33. What makes the human hand similar to a dolphin's flipper or a bat's wing? a. the ability to flap b. the structure of the skin c. the order of their evolution d. the structure and order of bones ______34. What does the similarity between humans, dolphins, cats, and bats indicate? a. that they all evolved recently b. that their ancestors lived in the same place c. that they share a common ancestor d. that they are becoming more alike over time ______35. If organisms with similar traits evolve from a common ancestor, what will they share? a. similar DNA b. similar arms and legs c. the ability to mate with each other d. similar fossils

Copyright © by Holt, Rinehart and Winston. All rights reserved.

Holt Science and Technology

4

The Evolution of Living Things

Back

Print

Name Class Date

Skills Worksheet

Directed Reading A

Section: How Does Evolution Happen?

1. List three things that scientists learned about Earth beginning in the 1800s.

CHARLES DARWIN ______ 2. What did Darwin do in order to study plants and animals? a. He took a trip around the world. b. He studied theology. c. He formed theories. d. He became a doctor. ______ 3. What did Darwin do during his travels? a. He wrote a book about his theory. b. He collected thousands of plant and animal samples. c. He took photos of plants and animals. d. He visited all the continents.

4. Darwin noticed that the plants and animals on the

were similar to, but not the same as, those in Ecuador.

5. What was one way that finches on different islands differed from each other?

6. What was the beak of each finch adapted to?

DARWIN'S THINKING ______ 7. What puzzled Darwin about the Galápagos finches? a. They were so different. b. They should not have been there. c. They were too similar. d. They were similar, but had many differences.

Copyright © by Holt, Rinehart and Winston. All rights reserved.

Holt Science and Technology

5

The Evolution of Living Things

Back

Print

Name Class Date

Directed Reading A continued

______ 8. A specific characteristic that can be passed from parent to offspring through genes is a(n) a. species. b. breeding. c. trait. d. adaptation.

9. What hypothesis did Darwin develop about the Galápagos finches?

10. What did Darwin do before presenting his new ideas?

Match the correct definition with the correct term. Write the letter in the space provided.

______11. the idea that human populations can grow faster than the food supply ______12. the idea that Earth had formed naturally over a long period of time ______13. the practice of breeding plants and animals to have desired traits

14. Why do farmers and breeders use selective breeding?

a. Lyell's theory b. selective breeding c. Malthus's principle

15. Why might selective breeding be used in horses?

16. Why might selective breeding be used in fruit trees?

Copyright © by Holt, Rinehart and Winston. All rights reserved.

Holt Science and Technology

6

The Evolution of Living Things

Back

Print

Name Class Date

Directed Reading A continued

17. After reading Malthus's theory, Darwin realized that any species can produce

many

.

18. The number of a species' offspring is limited by starvation, disease, predation,

or

. in

19. Darwin had begun to think that species could

their environment.

20. Darwin had begun to think that species could

over time.

21. What idea of Darwin's about species was supported by Charles Lyell's book?

DARWIN'S THEORY OF NATURAL SELECTION

22. What was the name of Darwin's famous book?

23. What theory did Darwin introduce in the book?

Match the correct description with the correct term. Write the letter in the space provided.

______24. Many more offspring are produced than will survive. ______25. No two offspring are alike. ______26. Many offspring will be killed before reproducing. ______ 27. The best adapted organisms will have many offspring.

a. inherited variation b. struggle to survive c. overproduction d. successful reproduction

28. List two things that Darwin did not know in relation to his theory.

Copyright © by Holt, Rinehart and Winston. All rights reserved.

Holt Science and Technology

7

The Evolution of Living Things

Back

Print

Name Class Date

Directed Reading A continued

29. Today, scientists explain natural selection in terms of changes in

.

30. Changes in genes occur when organisms produce 31. When organisms carry genes that make them more likely to survive to

.

reproduce, the process called

occurs.

Copyright © by Holt, Rinehart and Winston. All rights reserved.

Holt Science and Technology

8

The Evolution of Living Things

Back

Print

Name Class Date

Skills Worksheet

Directed Reading A

Section: Natural Selection in Action

______ 1. Bacteria passing resistance to a medicine on to offspring is an example of a. natural selection. c. genetic change. b. chemical action. d. overproduction. CHANGES IN POPULATIONS ______ 2. What does natural selection explain about a population? a. how long it has been since it evolved b. how it changes in response to its environment c. how it resists change d. how likely its members are to leave fossils ______ 3. Which individuals in a population are most likely to survive and reproduce? a. the largest ones b. the ones with the most DNA c. the best adapted ones d. the oldest ones ______ 4. The growing rate of tuskless elephants in Uganda is an example of a. selective breeding. c. adaptation. b. luck. d. speciation.

5. Why are tuskless elephants becoming more likely to reproduce than ones with tusks?

6. The ability of some insect species to resist chemicals is called

insecticide

.

7. The period of time between the birth of one generation and the birth of the

next is known as the

.

8. Insect species can develop resistance quickly because they have

short

.

9. Survival is only a part of natural selection. The other part takes place when

organisms

.

Copyright © by Holt, Rinehart and Winston. All rights reserved.

Holt Science and Technology

9

The Evolution of Living Things

Back

Print

Name Class Date

Directed Reading A continued

10. When competition for mates is intense, many organisms develop

to help attract mates. FORMING A NEW SPECIES

Match the correct description with the correct term. Write the letter in the space provided.

______11. the formation of new species ______12. changes in response to the environment ______13. the loss of ability of separated groups to interbreed ______14. the moving apart of populations

a. adaptation b. division c. separation d. speciation

15. Describe the process of forming a new species after separation.

16. When a portion of a population becomes isolated,

often begins.

17. Through adaptation, members of separated groups may develop

different

18. If environmental conditions differ,

. will also differ.

19. When members of related groups can no longer interbreed, they have become

members of different

.

Copyright © by Holt, Rinehart and Winston. All rights reserved.

Holt Science and Technology

10

The Evolution of Living Things

Back

Print

Name Class Date

Skills Worksheet

Directed Reading A

Section: Evidence of the Past

______ 1. What type of scientists use fossils to reconstruct the history of life before humans existed? a. fossilologists c. sedimentologists b. dinosaurologists d. paleontologists

2. What do fossils show us?

FOSSILS

3. What are fossils?

Put the three stages of fossil development in order from first to last. Write the appropriate numbers from 1 to 3 on the lines provided.

______ 4. Over time, the mold fills with sediment, which forms a cast of the organism. ______ 5. The organism gradually decomposes and leaves a hollow impression, or mold, in the sediment. ______ 6. When an organism dies it becomes buried in sediment. THE AGE OF FOSSILS

7. When scientists look at which layer of rock a fossil is in they are using the

method of estimating the age of rocks and fossils.

8. When a scientist finds sedimentary rock, where are the oldest layers usually found? Why?

9. Scientists can determine the age of a fossil more precisely than relative

dating using a method called

.

Copyright © by Holt, Rinehart and Winston. All rights reserved.

Holt Science and Technology

1

The History of Life on Earth

Back

Print

Name Class Date

Directed Reading A continued

10. The particles that make up all matter are called 11. As atoms decay what do they release?

.

12. The time it takes for half of the unstable atoms in a sample to decay is the

sample's

.

13. When scientists measure the ratio of unstable atoms to stable atoms in a sample of rock, what are they trying to determine?

THE GEOLOGIC TIME SCALE

14. Why is the earth's history divided into very long units of time?

15. The calendar scientists use to outline the history of life on earth is called the

time scale.

16. After paleontologists have dated a fossil, how do they use the time scale to help them understand how organisms have changed over time?

17. Paleontologists have divided the geologic time scale into blocks of time. The

largest divisions are known as

.

18. Why is the Mesozoic era is referred to as the Age of Reptiles?

19. Does the geologic time scale change? Explain why or why not?

Copyright © by Holt, Rinehart and Winston. All rights reserved.

Holt Science and Technology

2

The History of Life on Earth

Back

Print

Name Class Date

Directed Reading A continued

20. When a species dies out completely we say it has become

.

21. The periods when many species suddenly become extinct are called

.

22. What are two of the events scientists think could have caused the extinction of the dinosaurs?

THE CHANGING EARTH ______23. Fossils provide evidence that Antarctica was once located a. at the north pole. c. at the south pole. b. near the equator. d. where it is now. ______24. The continents may once have formed one landmass called Pangaea which means a. all seas. c. all Earth. b. puzzle. d. landmass. ______25. J. Tuzo Wilson's theory of how huge pieces of Earth's crust are pushed around by forces within the planet is called a. continents. c. plate tectonics. b. crust tectonics. d. Pangaea. ______26. According to the theory of plate tectonics, how many large rigid plates are there? a. five c. eight b. two d. seven

27. How are slow changes, such as moving continents, different than rapid changes, such as a meteorite impact?

28. Why are fossils found in some places very different than the organisms now living in the same area?

Copyright © by Holt, Rinehart and Winston. All rights reserved.

Holt Science and Technology

3

The History of Life on Earth

Back

Print

Name Class Date

Skills Worksheet

Directed Reading A

Section: Eras of the Geologic Time Scale

1. What are the four major divisions of geologic history?

PRECAMBRIAN TIME ______ 2. About how many years ago was the Precambrian time? a. 2.6 billion to 3.6 billion c. 430 million to 3.6 million b. 4.6 billion to 543 million d. 4.5 million to 300,000

3. What are two differences between early Earth and the present Earth?

4. How do scientists think that life on Earth developed?

5. The first organisms, called

, didn't need oxygen

to survive.

6. The first

began to release oxygen gas into the

oceans and air.

7. Organisms composed of many cells may have evolved from

.

8. Before a(n)

layer formed to reduce radiation on

Earth's surface, life existed only in the oceans and underground.

Copyright © by Holt, Rinehart and Winston. All rights reserved.

Holt Science and Technology

4

The History of Life on Earth

Back

Print

Name Class Date

Directed Reading A continued

THE PALEOZOIC ERA ______ 9. How many years ago was the Paleozoic era? a. 2.6 billion to 3.6 billion b. 430 million to 3.6 million c. 543 million to 248 million d. 4.5 million to 300,000

10. What are three of the fossils from the Paleozoic era?

11. Why is this era given the name Paleozoic, "ancient life"?

12. Name three of the plant species that covered Earth in the Paleozoic era.

Put the three types of animals in the order of their appearance on Earth. Write the appropriate numbers from 1 to 3 on the lines provided.

______13. salamander-like animals ______14. crawling insects ______15. reptiles and winged insects

16. What happened to as many as 90% of all Paleozoic organisms about 248 million years ago?

Copyright © by Holt, Rinehart and Winston. All rights reserved.

Holt Science and Technology

5

The History of Life on Earth

Back

Print

Name Class Date

Directed Reading A continued

THE MESOZOIC ERA

17. How many years ago was the Mesozoic era? a. 2.6 billion to 3.6 billion b. 248 million to 65 million c. 543 million to 248 million d. 430 million to 3.6 billion 18. What does "Mesozoic" mean?

19. Many reptiles evolved into different species during this time so the

Mesozoic Era is also known as the _____________________________________.

20. Name three types of animals that existed during the Mesozoic era.

21. About how many years ago did dinosaurs and many other plant and animal species become extinct?

THE CENOZOIC ERA ______22. The Cenozoic era began about 65 million years ago and a. ended 40 million years ago. b. continues to the present. c. ended in 1000 A.D. d. ended 35 thousand years ago. ______23. The Cenozoic era is sometimes called the a. Age of Humans. b. Age of Fossils. c. Age of Mammals. d. Age of Insects. ______24. Cenozoic means a. recent life. b. flowering plants. c. fossil era. d. saber-toothed cats.

Copyright © by Holt, Rinehart and Winston. All rights reserved.

Holt Science and Technology

6

The History of Life on Earth

Back

Print

Name Class Date

Directed Reading A continued

25. Name three of the Cenozoic animals.

26. What are two of the effects the ice ages have caused to organisms in the Cenozoic era?

Copyright © by Holt, Rinehart and Winston. All rights reserved.

Holt Science and Technology

7

The History of Life on Earth

Back

Print

Name Class Date

Skills Worksheet

Directed Reading A

Section: Humans and Other Primates

______ 1. Humans, apes, and monkeys had a common ancestor a. 3 million years ago. b. 4 thousand years ago. c. 45 million years ago. d. 1 billion years ago. PRIMATES ______ 2. Ancestors of primate were a. apelike. b. mouselike. c. birdlike. d. lizardlike. ______ 3. The first primate appeared a. at the same time as dinosaurs. b. before dinosaurs. c. after the dinosaurs died out. d. at the same time as humans.

4. The ancestors of

may have co-existed with

dinosaurs, but actual primates did not exist until after the dinosaurs.

5. What type of animal do scientists think is the closest living relative of humans?

6. Humans are in a family called

that includes only

humans and their humanlike ancestors.

7. The main characteristic that separates hominids from other primates is

. HOMINIDS THROUGH TIME ______ 8. Fossils are classified as hominids when they a. look like apes. b. share characteristics of modern humans. c. are found in the Cenozoic period. d. are found in Africa.

Copyright © by Holt, Rinehart and Winston. All rights reserved.

Holt Science and Technology

8

The History of Life on Earth

Back

Print

Name Class Date

Directed reading A continued

______ 9. The oldest hominid fossils have been found in a. Africa. c. Asia. b. North America. d. Australia. ______10. One of the earliest hominid fossils found is a. 3,000 to 4,000 years old. c. 6 to 7 million years old. b. 65 to 55 million years old. d. 100 to 200 million years old.

11. Early hominids that are similar to apes but different in several ways are

classified as

.

12. What are two of the differences between australopithecines and apes?

13. What are two differences between australopithecines and other hominids who lived at the same time?

14. About 2.3 million years ago, a more humanlike group of hominids called

appeared.

15. How were these new people different from australopithecines?

16. Members of one type of hominid group,

could

grow as tall as modern humans do. RECENT HOMINIDS

17. What two types of hominids may have lived in the same areas at the same time as recently as 30,000 years ago?

Copyright © by Holt, Rinehart and Winston. All rights reserved.

Holt Science and Technology

9

The History of Life on Earth

Back

Print

Name Class Date

Directed Reading A continued

18. What happened to the Neanderthals?

19. The group of hominids called

seems to be the first

to create art.

20. What indicates these early humans had an organized and complex society?

21. Why do paleontologists keep reviewing their hypotheses about hominids and human evolution?

Copyright © by Holt, Rinehart and Winston. All rights reserved.

Holt Science and Technology

10

The History of Life on Earth

Back

Print

Name Class Date

Skills Worksheet

Directed Reading A

Section: Sorting It All Out

1. What is classification?

WHY CLASSIFY? ______ 2. Putting plants and animals into orderly groups based on similar characteristics is called a. arrangement. c. identification. b. classification. d. biology. ______ 3. Classifying living things helps human beings a. improve the world. b. make sense of the world. c. destroy the world. d. make sense of the useful plants only. HOW DO SCIENTISTS CLASSIFY ORGANISMS? ______ 4. Taxonomy is the science of a. naming plants and animals. b. describing, classifying, and naming organisms. c. naming and describing living things. d. describing organisms. ______ 5. Carolus Linnaeus' seven-level system of classification a. included only plants. c. is still used today. b. is no longer used. d. does not include plants. ______ 6. The more closely related living things are to each other, the more a. characteristics they share. c. space they share. b. food they share. d. water they will share. ______ 7. Organisms are thought to be closely related when they have a. almost no characteristics in common. b. no characteristics in common. c. few characteristics in common. d. many characteristics in common.

Copyright © by Holt, Rinehart and Winston. All rights reserved.

Holt Science and Technology

1

Classification

Back

Print

Name Class Date

Directed Reading A continued

______ 8. Lions and house cats can both retract their claws, but brown bears and platypuses can not. Which two are most clearly related? a. lions and house cats. b. lions and platypuses. c. house cats and platypuses. d. house cats and brown bears.

9. Early scientists divided organisms into two groups. What were the two groups?

10. What Swedish botanist and physician created the first organized, modern taxonomy?

11. How many levels of classification do scientists use today?

12. Why are the platypus, brown bear, lion, and house cat thought to be related to each other?

13. What characteristics do the bear, lion, and house cat have that the platypus does not have?

LEVELS OF CLASSIFICATION ______14. All organisms are classified into a. one of six kingdoms. b. one of six phyla.

c. plants or animals. d. living or nonliving things.

______15. Each kingdom of organisms is divided into several a. genera. c. orders. b. classes. d. phyla. ______16. The smallest, most specific classification level is a. phylum. c. class. b. species. d. order.

17. The plural form of the word phylum is

Copyright © by Holt, Rinehart and Winston. All rights reserved.

.

Classification

Holt Science and Technology

2

Back

Print

Name Class Date

Directed Reading A continued

18. The singular form of the word genera is

.

19. In order from largest to smallest, what are the seven levels of classification?

SCIENTIFIC NAMES

20. No matter how many common names an organism might have, it only has one

.

21. How was the naming of organisms different before Carolus Linnaeus, and how was the system difficult for scientists?

22. Who simplified the naming of living things by giving each species a two-part scientific name?

23. In the scientific name for the Asian elephant, Elephas maximus, the word

Elephas indicates the animal's

24. All genus names begin with a(n) 25. All species names begin with a(n)

. .

.

26. Scientific names contain information about a(n) 27. Scientific names are usually in one of these two languages,

.

or

Copyright © by Holt, Rinehart and Winston. All rights reserved.

.

Holt Science and Technology

3

Classification

Back

Print

Name Class Date

Directed Reading A continued

28. In the scientific name Tyrannosaurus rex, rex, the Latin word for "King," is

the

name.

29. What abbreviation do scientists sometimes use when referring to Tyrannosaurus rex?

30. What is the scientific name for the common house cat?

DICHOTOMOUS KEYS ______31. Scientists use dichotomous keys to a. name organisms. c. identify organisms. b. count organisms. d. catch organisms.

32. What kind of identification aid are scientists using when they work through a series of paired, descriptive statements?

33. In your own words, describe how a dichotomous key is used to identify an organism.

A GROWING SYSTEM ______34. All the organisms on the Earth have a. been discovered. b. been classified. c. not been discovered or classified. d. been given scientific names. ______35. What do scientists do when a newly-discovered organism does not fit any existing category? a. leave the organism alone b. try to change the organism c. destroy the organism d. create a new category ______36. What newly-discovered organism, first found in 1995 on lobster lips, did not fit in any existing phyla? a. Symbion pandora c. Elephas maximus b. Felis domesticus d. Tyrannosaurus rex

Copyright © by Holt, Rinehart and Winston. All rights reserved.

Holt Science and Technology

4

Classification

Back

Print

Name Class Date

Skills Worksheet

Directed Reading A

Section: The Six Kingdoms

1. Before the discovery of organisms like Euglena, all organisms were

classified as either WHAT IS IT?

or

.

______ 2. Scientists classify organisms based on their what? a. shape c. size b. smell d. characteristics ______ 3. Which characteristic is not true for organisms of the genus Euglena? a. single celled c. live in pond water b. live in salt water d. make their own food ______ 4. A green color and the ability to make food through photosynthesis might make some people think that members of the genus Euglena are a. trees. c. plants. b. algae. d. mosses. ______ 5. Which is a characteristic that animals and members of the genus Euglena possess but plants do not? a. ability to move by themselves c. ability to take in water b. ability to make food d. ability to use energy 6. Scientists added the kingdom

, creating a

classification for organisms that had characteristics of both plants and animals.

7. Do you think there will always be six kingdoms used for classifying organisms? Explain.

THE TWO KINGDOMS OF BACTERIA

8. Bacteria are

, or organisms that lack nuclei.

9. Many scientists divide bacteria into two kingdoms:

and

.

Copyright © by Holt, Rinehart and Winston. All rights reserved.

Holt Science and Technology

5

Classification

Back

Print

Name Class Date

Directed Reading A continued

Identify the correct bacteria kingdom for the organisms described below by writing Archaebacteria or Eubacteria in the space provided.

10. Some of these live inside humans. 11. One of these causes pneumonia. 12. These live in places where most other organisms could not live. 13. Its name comes from a word that means "ancient." 14. One type turns milk into yogurt.

KINGDOM PROTISTA ______15. Members of the kingdom Protista are called a. plants. b. animals. c. protists. d. fungi.

16. Protists that have animal-like characteristics are called

.

17. Protists that have plant-like characteristics are called

.

18. An example of a fungus-like protist is a(n)

. KINGDOM FUNGI ______19. Unlike plants, fungi do not a. use photosynthesis. b. move around. c. eat food. d. need water. ______20. Unlike animals, fungi do not a. use photosynthesis. b. eat food. c. need water. d. require energy.

Copyright © by Holt, Rinehart and Winston. All rights reserved.

Holt Science and Technology

6

Classification

Back

Print

Name Class Date

Directed Reading A continued

______21. Fungi absorb nutrients from their surroundings by a. the process of photosynthesis. b. breaking them down with digestive juices. c. surrounding and engulfing them. d. eating like animals.

22. Give two examples of fungi.

KINGDOM PLANTAE

23. What do all members of the kingdom Plantae have in common?

24. In order for plants to make their own food through photosynthesis, they must

be exposed to

25. Plants can be found growing on

. and in

that light can penetrate.

26. Explain why the food that plants make is important not only to the plants themselves but to other organisms as well.

27. Plants provide nutrients for other organisms. What is another way that trees and other flowering plants are used by animals?

Copyright © by Holt, Rinehart and Winston. All rights reserved.

Holt Science and Technology

7

Classification

Back

Print

Name Class Date

Directed Reading A continued

KINGDOM ANIMALIA ______28. Most members of kingdom Animalia share which of the following characteristics? a. They are unicellular and green. b. They have cell walls. c. They are multicellular and can move. d. They have feathers or hair. ______29. Members of kingdom Animalia have specialized sense organs that allow them to a. digest their food. b. grow. c. respond to their environment. d. rest.

30. Members of kingdom Animalia are commonly called

.

31. Explain how animals need plants.

32. Explain how animals depend on bacteria and fungi.

33. The kingdom Animalia includes some very simple members, such as

, that do not have sense organs and cannot move.

Copyright © by Holt, Rinehart and Winston. All rights reserved.

Holt Science and Technology

8

Classification

Back

Print

Name Class Date

Skills Worksheet

Directed Reading A

Section: Bacteria

______ 1. Which of the following is true of bacteria? a. All bacteria are the same size. b. Most bacteria can be seen without a microscope. c. There are fewer bacteria on Earth than most other living things. d. There are more bacteria on Earth than any other living thing. CHARACTERISTICS OF BACTERIA ______ 2. How many kingdoms of living things are there? a. one c. six b. two d. ten ______ 3. What two kingdoms of living things do bacteria belong to? a. Eubacteria and Archaebacteria b. Fungi and Animalia c. Archaebacteria and Fungi d. Protista and Plantae ______ 4. Eubacteria and Archaebacteria contain a. all of the forms of life on Earth. b. the oldest forms of life on Earth. c. the youngest forms of life on Earth. d. none of the forms of life on Earth. ______ 5. All bacteria have a. one cell. b. two cells. c. three cells. d. hundreds of cells. ______ 6. Which of the following is NOT one of the most common shapes of bacteria? a. cocci b. spirilla c. flagella d. bacilli ______ 7. What determines a bacteria's shape? a. its size b. the kingdom it belongs to c. its color d. its cell wall

Copyright © by Holt, Rinehart and Winston. All rights reserved.

Holt Science and Technology

1

Bacteria and Viruses

Back

Print

Name Class Date

Directed Reading A continued

Match the correct description with the correct term. Write the letter in the space provided.

______ 8. rod-shaped ______ 9. long, spiral-shaped ______10. spherical

11. Some bacteria use hairlike parts called

a. cocci b. bacilli c. spirilla

to help

them move around.

12. Bacteria are organisms with one cell and no 13. An organism with no nucleus is a(n) 14. An organism with a nucleus is a(n)

. . .

15. What three things can a prokaryote do that allow it to function as an independent organism?

16. Bacteria reproduce by

.

17. Describe how bacteria reproduce through binary fission.

18. What kind of places do most bacteria grow best in?

19. What kind of places do some bacteria not grow well in?

20. Genetic material covered by a thick, protective membrane is a(n)

.

Copyright © by Holt, Rinehart and Winston. All rights reserved.

Holt Science and Technology

2

Bacteria and Viruses

Back

Print

Name Class Date

Directed Reading A continued

21. How is it possible that a bacteria could begin to grow after 30 million years in a fossilized insect's stomach?

KINGDOM EUBACTERIA ______22. Most bacteria are a. archaebacteria. b. protista.

c. fungi. d. eubacteria.

______23. The kingdom that has the most organisms is a. Fungi. c. Eubacteria. b. Archaebacteria. d. Protista. ______24. Eubacteria are classified by a. their size. b. their shape. ______25. Most eubacteria are a. consumers. b. producers.

c. the way they get food. d. the way they reproduce. c. decomposers. d. food sources.

Match the correct description with the correct term. Write the letter in the space provided.

______26. bacteria that get their food from dead organic matter ______ 27. bacteria that eat other organism or live in or on the body of another ______28. bacteria that make their own food

29. What do producer bacteria use to make food?

a. producers b. decomposers c. consumers

30. A bacterium that contains the green pigment chlorophyll is

.

31. Many cyanobacteria contain

that give them

different colored tints.

Copyright © by Holt, Rinehart and Winston. All rights reserved.

Holt Science and Technology

3

Bacteria and Viruses

Back

Print

Name Class Date

Directed Reading A continued

32. How do flamingos get their pink color?

KINGDOM ARCHAEBACTERIA

Match the correct definition with the correct term. Write the letter in the space provided.

______33. bacteria that live in swamps and animal intestines

a. heat lovers b. salt lovers c. methane makers

______34. bacteria that live in ocean vents and hot springs ______35. bacteria that live in salty environments

36. One kind of organism that often lives where no other organism can is a(n)

.

37. What kind of environment do archaebacteria prefer?

38. What are three places where archaebacteria have been found?

39. How are archaebacteria different from eubacteria?

Copyright © by Holt, Rinehart and Winston. All rights reserved.

Holt Science and Technology

4

Bacteria and Viruses

Back

Print

Name Class Date

Skills Worksheet

Directed Reading A

Section: Bacteria's Role in the World

1. What are three places where bacteria live?

GOOD FOR THE ENVIRONMENT ______ 2. Which of the following is true? a. All bacteria are bad. b. Bacteria do not help the Earth in any way. c. Bacteria play a harmful role in the nitrogen cycle. d. Bacteria are necessary for life on Earth. ______ 3. Bacteria help the environment by a. causing disease. b. helping to recycle dead animals and plants. c. causing cavities. d. keeping nitrogen away from plants. ______ 4. Plants get nitrogen from a. air. b. water.

c. soil. d. bacteria.

5. Why can't plants use the nitrogen in the air?

6. What happens to the nitrogen that is in the air so that plants can use it?

7. The process in which bacteria change the form of nitrogen so plants can use

it is called

.

8. How do bacteria recycle leaves and twigs?

Copyright © by Holt, Rinehart and Winston. All rights reserved.

Holt Science and Technology

5

Bacteria and Viruses

Back

Print

Name Class Date

Directed Reading A continued

9. Why is it important to break down dead matter?

10. The use of microorganisms to treat hazardous waste is called

.

11. Why are bacteria and other microorganisms used to fight pollution?

GOOD FOR PEOPLE ______12. What is one way bacteria are good for people? a. They prevent cavities. b. They are used to make many foods. c. They cause diseases. d. They keep skin and hair clean. ______13. Which of the following is NOT made from bacteria? a. buttermilk c. regular milk b. cheese d. yogurt

14. The sugar in milk is called 15. How do bacteria make lactic acid?

.

16. Medicines used to kill bacteria and other microorganisms are

.

17. Many antibiotics are made from 18. How are bacteria used to make insulin?

.

Copyright © by Holt, Rinehart and Winston. All rights reserved.

Holt Science and Technology

6

Bacteria and Viruses

Back

Print

Name Class Date

Directed Reading A continued

19. Changing the genes of bacteria or other living things is called

.

20. How did scientists get a bacterium to make copies of the frog gene?

21. Give an example of other products scientists can make using genetic engineering.

HARMFUL BACTERIA ______22. Pathogenic bacteria are bacteria that a. cause disease. b. change lactose to lactic acid. c. change harmful chemicals to harmless ones. d. change the form of nitrogen so plants can use it. ______23. What do pathogenic bacteria do once they are inside a host organism? a. break down lactose b. take nutrients from the host's cell c. change harmful cells to harmless ones d. consume harmful organisms ______24. What helps protect a person from a particular bacterial disease? a. bioremediation c. genetic engineering b. a vaccine d. insulin ______25. What is used to treat a particular bacterial disease? a. bioremediation c. genetic engineering b. a vaccine d. an antibiotic ______26. A plant with odd-colored spots has been attacked by a. bacteria. c. heat. b. spiders. d. cold.

Copyright © by Holt, Rinehart and Winston. All rights reserved.

Holt Science and Technology

7

Bacteria and Viruses

Back

Print

Name Class Date

Directed Reading A continued

27. Name three organisms other than humans that can be attacked by pathogenic bacteria.

28. What are two ways to protect plants from disease-causing bacteria?

Copyright © by Holt, Rinehart and Winston. All rights reserved.

Holt Science and Technology

8

Bacteria and Viruses

Back

Print

Name Class Date

Skills Worksheet

Directed Reading A

Section: Viruses

______ 1. What is a virus? a. a tiny particle that gets inside a cell and often destroys it b. a type of bacteria that invades cells c. a type of disease d. a cold

2. Name three diseases caused by viruses.

IT'S A SMALL WORLD ______ 3. Which of the following is true? a. Viruses are smaller than bacteria. b. Bacteria are smaller than viruses. c. Bacteria and viruses are about the same size. d. There are about 5 billion types of viruses. ______ 4. What is one of a virus's properties? a. can change shapes c. can change often and rapidly b. can change slowly d. can grow larger quickly

5. Why are scientists unable to tell exactly how many different types of viruses there are?

6. What two things make it difficult to fight viruses?

Copyright © by Holt, Rinehart and Winston. All rights reserved.

Holt Science and Technology

9

Bacteria and Viruses

Back

Print

Name Class Date

Directed Reading A continued

ARE VIRUSES LIVING?

Determine whether each of the following statements is evidence that viruses are living or nonliving. Write L for living or N for nonliving in the space provided.

______ 7. Viruses contain protein and genetic material. ______ 8. Viruses have no cytoplasm. ______ 9. Viruses don't eat, grow, or use oxygen. ______10. Viruses cannot break down food. ______11. Viruses can reproduce.

12. Where is the only place a virus can reproduce?

13. The cell that a virus lives on or in is called a 14. Once a virus has entered a living cell, what does it force the cell to do?

.

CLASSIFYING VIRUSES

15. What characteristics do scientists use to group viruses?

Copyright © by Holt, Rinehart and Winston. All rights reserved.

Holt Science and Technology

10

Bacteria and Viruses

Back

Print

Name Class Date

Directed Reading A continued

Match the correct description with the correct term. Write the letter in the space provided.

______16. What do HIV and the virus that causes influenza look like? ______ 17. What does a group of viruses that attacks only bacteria look like? ______18. What is the tobacco mosaic virus shaped like? ______19. What is the polio virus shaped like?

20. How does a virus's protein coat help a virus?

a. crystals b. spacecraft c. spheres d. cylinders

21. Give two examples of viruses that contain the genetic material DNA.

22. Give three examples of viruses that contain the genetic material RNA.

A DESTRUCTIVE HOUSE GUEST ______23. The cycle in which viruses attack living cells and turn them into virus factories is called the a. factory cycle. c. lytic cycle. b. reproduction cycle. d. virus cycle.

Put the following events in the order of their occurrence in the lytic cycle by numbering them 1­4. Write the number in the space provided.

______24. The host cell replicates the virus's genes. ______25. The host cell is destroyed. ______26. The virus's genes enter the host. ______ 27. The virus finds a host cell.

Copyright © by Holt, Rinehart and Winston. All rights reserved.

Holt Science and Technology

11

Bacteria and Viruses

Back

Print

Name Class Date

Directed Reading A continued

28. A cycle in which viruses put their genetic material in a host cell but do not

make new viruses right away is the

29. Describe one way the lytic and lysogenic cycles are different.

cycle.

30. In the

cycle, the virus's genes are inactive for

long periods of time.

31. Why are viruses hard to treat?

32. How do antiviral medications work?

33. How can people help prevent viral infections?

Copyright © by Holt, Rinehart and Winston. All rights reserved.

Holt Science and Technology

12

Bacteria and Viruses

Back

Print

Name Class Date

Skills Worksheet

Directed Reading A

Section: Protists

______ 1. What kingdom do protists belong to? a. Plant c. Protista b. Animal d. Fungus GENERAL CHARACTERISTICS ______ 2. Most protists are made of how many cells? a. four c. two b. three d. one

3. All protists are

, which means that each of their

cells has a nucleus.

4. What are two examples of protists?

5. Name three traits that can differ among protists.

6. How do protists differ from other eukaryotic organisms?

PROTISTS AND FOOD ______ 7. What function do chloroplasts perform in protist producers? a. capture energy from the sun c. capture organisms to eat b. give the protist shape d. help the protist move

Copyright © by Holt, Rinehart and Winston. All rights reserved.

Holt Science and Technology

1

Protists and Fungi

Back

Print

Name Class Date

Directed Reading A continued

8. What is the term for the process protists use to make their own food?

9. Name two ways protists get food.

10. A protist that makes its own food is a(n) 11. Organisms that cannot make their own food are

.

that must get food from the environment.

12. Many heterotrophs are

, which invade other

organisms to get nutrients.

13. An organism invaded by a parasite for nutrients is called a(n)

.

14. Protist heterotrophs that break down dead matter for energy are

.

15. What do most protist heterotrophs eat?

16. In what three ways do protist heterotrophs get food?

17. Name one example of a parasite causing harm to its host.

Copyright © by Holt, Rinehart and Winston. All rights reserved.

Holt Science and Technology

2

Protists and Fungi

Back

Print

Name Class Date

Directed Reading A continued

PRODUCING MORE PROTISTS ______18. In asexual reproduction, how many parents are there? a. one c. three b. two d. four ______19. In asexual reproduction, what process do single-celled protists use to divide into two cells? a. conjugation c. multiple fission b. binary fission d. single-cell fission ______20. What process do single-celled protists use in asexual reproduction to make more than two offspring from one parent? a. conjugation c. multiple fission b. binary fission d. single-cell fission ______21. How do paramecia sometimes reproduce sexually? a. conjugation c. multiple fission b. binary fission d. single-cell fission

22. What is conjugation?

23. When will a protist that normally reproduces asexually reproduce sexually?

24. What is an example of a protist with a complex reproductive cycle?

25. Summarize the five steps it takes for Plasmodium vivax to complete its reproductive cycle.

Copyright © by Holt, Rinehart and Winston. All rights reserved.

Holt Science and Technology

3

Protists and Fungi

Back

Print

Name Class Date

Skills Worksheet

Directed Reading A

Section: Kinds of Protists

1. What three groups can scientists use to organize protists based on shared traits?

PROTIST PRODUCERS ______ 2. What is the name for protists that convert the sun's energy into food? a. slime molds b. algae c. amoebas d. parasites ______ 3. All types of algae have what color pigment? a. red b. blue c. brown d. green ______ 4. Where do most types of algae live? a. in dirt b. in water c. in sand d. in plants ______ 5. Which of the following is an alga that lives in shallow water along the shore? a. phytoplankton b. seaweed c. water mold d. radiolarian ______ 6. Which of the following provides most of the world's oxygen? a. phytoplankton b. seaweed c. amoebas d. flagellates

Copyright © by Holt, Rinehart and Winston. All rights reserved.

Holt Science and Technology

4

Protists and Fungi

Back

Print

Name Class Date

Directed Reading A continued

Match the correct definition with the correct term. Write the letter in the space provided.

______ 7. the algae group most of the world's seaweeds belong to ______ 8. the protist producers that use photosynthesis to make food ______ 9. the main pigment in these algae cells is chlorophyll ______10. the cell of this organism contains a glasslike substance called silica ______11. many individual protists living together as a group ______12. free-floating single-celled algae ______13. seaweeds that live in cool climates

14. Name four places where green algae live.

a. brown algae b. algae c. green algae d. phytoplankton e. colony f. red algae g. diatoms

15. Individual cells of some green algae live in groups

called

.

16. Name three facts about brown algae.

17. Where are diatoms found?

18. The cell walls of diatoms contain

.

Copyright © by Holt, Rinehart and Winston. All rights reserved.

Holt Science and Technology

5

Protists and Fungi

Back

Print

Name Class Date

Directed Reading A continued

19. The whip-like strands on a dinoflagellate that cause the cells to spin through

water are called

20. Most dinoflagellates get their energy from

. , but a , or

few are .

,

21. Why don't euglenoids fit easily into one protist group?

HETEROTROPHS THAT CAN MOVE ______22. What are mobile protists sometimes called? a. protozoans b. radiolarians c. foraminiferans d. paramecium

23. Where can amoebas be found?

24. What two things does an amoeba use pseudophia for?

25. How is a food vacuole formed?

26. What is the purpose of a food vacuole?

Copyright © by Holt, Rinehart and Winston. All rights reserved.

Holt Science and Technology

6

Protists and Fungi

Back

Print

Name Class Date

Directed Reading A continued

Match the correct definition with the correct term. Write the letter in the space provided.

______ 27. These are tiny, hairlike structures. ______28. These have shells that look like glass ornaments. ______29. This protist can live in the digestive tract of vertebrates. ______30. This controls the functions of a ciliate's cell. ______31. These have snail-like shells.

32. What does the term mutualism mean?

a. cilia b. radiolarians c. Giardia lamblia d. foraminiferans e. macronucleus

33. What are the two uses for cilia?

34. In a ciliate, the

passes genes to another

paramecium during sexual reproduction. HETEROTROPHS THAT CAN'T MOVE

35. Name two characteristics of spore-forming protists.

36. Besides water, where do water molds live?

37. What are the two ways water molds get their food?

Copyright © by Holt, Rinehart and Winston. All rights reserved.

Holt Science and Technology

7

Protists and Fungi

Back

Print

Name Class Date

Directed Reading A continued

38. Describe the appearance of a slime mold.

39. Slime molds use pseudopodia to eat bacteria and 40. Small reproductive cells that are covered by a thick cell wall are

.

called

.

41. When do spores develop into new slime molds?

Copyright © by Holt, Rinehart and Winston. All rights reserved.

Holt Science and Technology

8

Protists and Fungi

Back

Print

Name Class Date

Skills Worksheet

Directed Reading A

Section: Fungi

CHARACTERISTICS OF FUNGI

1. What are fungi?

2. How do fungi get nutrients?

3. Many fungi are

, which feed on dead plant or .

animal matter, while other fungi are

4. Explain how plants and fungi can benefit from each other through a mycorrhiza.

Match the correct definition with the correct term. Write the letter in the space provided.

______ 5. a beneficial relationship between a plant and a fungus ______ 6. the twisted mass that forms when hyphae grow together ______ 7. threadlike fungal fibers ______ 8. the small reproductive cells that are protected by a thick cell wall

a. hyphae b. spores c. mycorrhiza d. mycelium

Copyright © by Holt, Rinehart and Winston. All rights reserved.

Holt Science and Technology

9

Protists and Fungi

Back

Print

Name Class Date

Directed Reading A continued

9. All fungi are made of 10. Where is the mycelium found?

cells.

11. Describe the two types of asexual reproduction that take place in fungi.

12. Sexual reproduction in fungi happens when special structures form

to make KINDS OF FUNGI

.

______13. Which of the following type of fungus is shapeless and fuzzy? a. yeast c. mold b. penicillium d. mushroom ______14. Which of the following groups does black bread mold belong to? a. threadlike fungi c. club fungi b. sac fungi d. imperfect fungi ______15. Where do most of the threadlike fungi live? a. in soil c. in water b. in another organism d. in sand ______16. What are the spore cases on threadlike fungi called? a. sacs c. spore mold b. sporangia d. morels

17. Name the four groups of fungi.

18. Describe the two types of reproduction that take place in threadlike fungi.

Copyright © by Holt, Rinehart and Winston. All rights reserved.

Holt Science and Technology

10

Protists and Fungi

Back

Print

Name Class Date

Directed Reading A continued

19. The largest group of fungi are 20. Some examples of sac fungi are

. , , and

, .

21. When sac fungi reproduce sexually, they form a sac

called a(n)

22. Name two ways sac fungi are useful.

.

Match the correct definition with the correct term. Write the letter in the space provided. Some terms will not be used.

______23. a form of asexual reproduction used by yeasts ______24. a disease caused by sac fungi ______25. the group of fungi mushrooms belong to ______26. clublike structures on club fungi ______ 27. a fungi that grows outward from wood and forms small shelves ______28. a poison produced by an imperfect fungi ______29. a fungi used to make an antibiotic

30. Why do mushrooms often appear in circles?

a. threadlike fungi b. basidia c. budding d. club fungi e. chestnut blight f. bracket fungi g. Penicillium h. aflatoxin

31. The most familiar mushrooms are

fungi.

Copyright © by Holt, Rinehart and Winston. All rights reserved.

Holt Science and Technology

11

Protists and Fungi

Back

Print

Name Class Date

Directed Reading A continued

32. Bracket fungi, puffballs, smuts, and rusts are all

fungi.

33. Imperfect fungi do not reproduce 34. A common human skin disease caused by imperfect fungi

.

is LICHENS

.

______35. A lichen is a combination of what two organisms? a. fungus and alga c. fungus and mushroom b. alga and yeast d. yeast and mushroom ______36. Because lichens produce their food through photosynthesis, which group do they belong to? a. consumers c. producers b. parasites d. hosts

37. What allows lichens to live in even the driest environments without drying out?

38. Why can lichens grow on rocks?

39. Give one example of how a lichen changes its surroundings in a way that allows other organisms to live there.

40. Why are lichens easily affected by air pollution?

Copyright © by Holt, Rinehart and Winston. All rights reserved.

Holt Science and Technology

12

Protists and Fungi

Back

Print

Name Class Date

Skills Worksheet

Directed Reading A

Section: What Is a Plant?

1. Why couldn't you eat much without plants?

PLANT CHARACTERISTICS ______ 2. What is the name of the green pigment that captures energy from the sun? a. organelles c. carbon dioxide b. chlorophyll d. chloroplasts ______ 3. Plants use energy from sunlight to make food from carbon dioxide and water. This process is called a. chloroplasts. c. photosynthesis. b. organelles. d. producers. ______ 4. What does the cuticle do? a. It captures energy from the sun. b. It creates air. c. It keeps plants from drying out. d. It grows into chloroplasts.

Match the correct definition with the correct term. Write the letter in the space provided.

______ 5. rigid structure that surrounds a plant cell ______ 6. structure that contains chlorophyll ______ 7. chamber that stores water ______ 8. a substance that forms a hard material in cell walls ______ 9. structure that lies beneath the cell wall

10. Plants make spores in the

a. vacuole b. cell membrane c. cell wall d. carbohydrates e. chloroplast

stage.

Copyright © by Holt, Rinehart and Winston. All rights reserved.

Holt Science and Technology

1

Introduction to Plants

Back

Print

Name Class Date

Directed Reading A continued

11. When the spores of some plants grow, the new plants are

called

. .

12. The fertilized egg of a gametophyte grows into a(n)

PLANT CLASSIFICATION

Match the correct definition with the correct term. Write the letter in the space provided.

______13. an example of a nonvascular plant ______14. plants without specialized conducting tissues ______15. an example of a seedless vascular plant ______16. plants have tissues to deliver water and nutrients from one part of the plant to another ______ 17. vascular seed plant that does not flower

______18. flowering plant with seeds inside a fruit

a. nonvascular plants b. vascular plants c. gymnosperm d. angiosperm e. fern f. liverwort

THE ORIGIN OF PLANTS

19. Scientists think modern green algae and plants are descended from ancient green algae that lived in the oceans. What are the similarities between modern green algae and plants?

Copyright © by Holt, Rinehart and Winston. All rights reserved.

Holt Science and Technology

2

Introduction to Plants

Back

Print

Name Class Date

Skills Worksheet

Directed Reading A

Section: Seedless Plants

1. List the two groups of seedless plants.

NONVASCULAR PLANTS ______ 2. Nonvascular plants get the water they need a. from rhizomes. b. from the environment or nearby cells. c. from the ground through their roots. d. from vascular tissues. ______ 3. Rhizoids are like roots because a. they contain vascular tissue. b. they do not contain vascular tissue. c. they help hold the plant in place. d. they live in large groups. ______ 4. Rhizoids help nonvascular plants a. become tall and leafy. b. develop vascular parts. c. obtain water and nutrients. d. produce spores. ______ 5. Which of the following is true of liverworts? a. They usually live in dry places. b. They are very large. c. They are vascular plants. d. Their gametophytes can be mosslike and leafy.

6. List three reasons why nonvascular plants are important.

SEEDLESS VASCULAR PLANTS

7. Ancient

grew to 40 m, but are smaller today.

Copyright © by Holt, Rinehart and Winston. All rights reserved.

Holt Science and Technology

3

Introduction to Plants

Back

Print

Name Class Date

Directed Reading A continued

8. An underground stem from which new leaves and roots grow is called

a(n)

9. Describe the fern gametophyte.

.

10. Young fronds are called

because of how they are

coiled.

Match the correct definition with the correct term. Write the letter in the space provided.

______11. structure where silica is found in horsetails ______12. substance that has a gritty texture ______13. plants that have life cycles similar to horsetails ______14. pioneers used them to scrub pans ______15. height of some modern horsetails ______16. height of some modern club mosses ______ 17. plants that grow in woodlands ______18. tissue found in club mosses but not in mosses

a. 20 cm b. club mosses c. stem d. horsetails e. vascular tissue f. silica g. 8 m h. ferns

19. What roles do seedless vascular plants play in the environment?

Copyright © by Holt, Rinehart and Winston. All rights reserved.

Holt Science and Technology

4

Introduction to Plants

Back

Print

Name Class Date

Directed Reading A continued

20. Name two kinds of seedless vascular plants that are popular houseplants.

21. Name two kinds of seedless vascular plants that can be eaten by humans.

22. In what way are fossilized seedless vascular plants that died 3 million years ago important to humans?

Copyright © by Holt, Rinehart and Winston. All rights reserved.

Holt Science and Technology

5

Introduction to Plants

Back

Print

Name Class Date

Skills Worksheet

Directed Reading A

Section: Seed Plants

1. How are gymnosperms and angiosperms different?

CHARACTERISTICS OF SEED PLANTS

Fill in each blank with either "seedless plants" or "seed plants."

2. In

, the gametophytes do not live independently of

the sporophytes.

3. The gametophytes of

form within the reproductive

structures of the sporophyte.

4. The sperm of

need water to swim to the eggs of

female gametophytes.

5. The sperm of

can reach the eggs without the help

of water.

6. The sperm of

form inside of pollen, which is

carried by wind or by animals

7. The most common plants on Earth are

.

Copyright © by Holt, Rinehart and Winston. All rights reserved.

Holt Science and Technology

6

Introduction to Plants

Back

Print

Name Class Date

Directed Reading A continued

THE STRUCTURE OF SEEDS

Match the correct definition with the correct term. Write the letter in the space provided.

______ 8. the young plant within a seed ______ 9. structure that surrounds and protects the young plant ______10. seed leaves of a young plant ______11. joining of sperm and egg ______12. often the purpose of the cotyledons

13. Name two advantages of seeds over spores.

a. cotyledons b. fertilization c. food storage d. seed coat e. sporophyte

GYMNOSPERMS ______14. Seed plants that do not have flowers or fruit are called a. sporophytes. c. gametophytes. b. angiosperms. d. gymnosperms.

______15. Gymnosperm seeds are usually protected by a. leaves. c. fruits. b. cones. d. humans.

______16. The most economically important gymnosperms are the a. conifers. c. cycads. b. ginkgoes. d. gnetophytes. ______ 17. Three things that conifers are used for are a. building materials, cancer drugs, and gardens and parks. b. paper products, resin, and syrup. c. allergy drugs, leather, and resin. d. building materials, fresh fruit, and gardens and parks.

Copyright © by Holt, Rinehart and Winston. All rights reserved.

Holt Science and Technology

7

Introduction to Plants

Back

Print

Name Class Date

Directed Reading A continued

Match the correct definition with the correct term. Write the letter in the space provided.

______18. most are evergreens ______19. group of gymnosperms that are shrubs that grow in dry areas ______20. group of gymnosperms with only one living species ______21. gymnosperms that grow in the Tropics

22. During the pine life cycle, sex cells are produced in the

a. ginkgoes b. cycads c. conifers d. gnetophytes

.

23. The male

of gymnosperms are found in pollen.

24. Pollen is carried from the male cone to the female cone

by

. .

25. Some pine cones release seeds only during

26. The transfer of pollen from the male reproductive structures to the female

reproductive structures of seed plants is called ANGIOSPERMS ______ 27. About how many species of angiosperms can be found today? a. over 1,000 b. at least 235,000 c. just a few d. over one million

28. How are angiosperm fruits and seeds transported to new areas?

.

Copyright © by Holt, Rinehart and Winston. All rights reserved.

Holt Science and Technology

8

Introduction to Plants

Back

Print

Name Class Date

Directed Reading A continued

Each of the following phrases describes, or is an example of, either a monocot or a dicot. In the space provided, write M for a monocot and D for a dicot.

______29. plant that has one cotyledon (seed leaf) ______30. vascular tissue in bundles that are scattered ______31. plant that has leaves with branching veins ______32. flower parts in threes ______33. vascular tissue in a ring ______34. flower parts in fours or fives

35. Explain the difference between the way that a field mouse and the way that an owl benefit from flowering plants.

36. List three ways that people use flowering plants.

Copyright © by Holt, Rinehart and Winston. All rights reserved.

Holt Science and Technology

9

Introduction to Plants

Back

Print

Name Class Date

Skills Worksheet

Directed Reading A

Section: Structures of Seed Plants

______ 1. Vascular tissue that transports water and minerals through a plant is called a. shoots. c. phloem. b. xylem. d. leaves. ______ 2. Vascular tissue that transports food molecules to all parts of a plant is called a. shoots. c. phloem. b. xylem. d. leaves. ROOTS

3. Most root systems are located 4. What are the three main functions of roots?

.

Match the correct definition with the correct term. Write the letter in the space provided.

______ 5. cells of the epidermis that extend from the root ______ 6. group of cells that produces a slimy substance ______ 7. root system with one main root ______ 8. layer of cells that cover root surfaces ______ 9. plants that usually have fibrous roots ______10. structure protected by the root cap ______11. what root hairs increase ______12. root system in which roots are usually the same size

Copyright © by Holt, Rinehart and Winston. All rights reserved.

a. fibrous root b. root tip c. epidermis d. surface area e. taproot f. root hairs g. monocots h. root cap

Holt Science and Technology

10

Introduction to Plants

Back

Print

Name Class Date

Directed Reading A continued

STEMS ______13. Which of the following is NOT true about stems? a. Stems are always located above the ground. b. Stems connect the roots to the leaves and flowers. c. Stems display flowers to pollinators. d. Stems can store water. ______14. What does xylem do? a. It carries food to plant parts. b. It dissolves minerals and food. c. It carries water and minerals from the roots to the leaves. d. It grows longer roots. ______15. What does phloem do? a. It carries food to plant parts. b. It participates in photosynthesis. c. It takes water and minerals to stems. d. It dissolves minerals. ______16. Stems that are soft, thin, and flexible are a. xylem. b. herbaceous. c. phloem. d. woody.

17. Name two examples of plants with herbaceous stems.

18. What is a growth ring?

Copyright © by Holt, Rinehart and Winston. All rights reserved.

Holt Science and Technology

11

Introduction to Plants

Back

Print

Name Class Date

Directed Reading A continued

LEAVES

______19. What is the main function of leaves? a. They create water for the plant. b. They keep insects away from the plant. c. They make food for the plant. d. They absorb oxygen for the plant. 20. From top to bottom, list the four layers in a leaf.

21. Most photosynthesis takes place in the

in the

middle of the leaf.

Match the correct definition with the correct term. Write the letter in the space provided.

______22. cells that open and close the stomata ______23. layer of cells that contains many chloroplasts ______24. a single layer of cells beneath the cuticle ______25. a tiny opening that allows carbon dioxide to enter the leaf ______26. layer where carbon dioxide moves freely and xylem and phloem are found ______ 27. structure that prevents water loss from the leaf

28. Cactus spines are

a. stoma b. guard cells c. spongy layer d. epidermis e. palisade layer f. cuticle

that protect cactuses

from animals.

29. The leaves of the sundew plant catch

, which are

digested to provide nitrogen to the plant.

Copyright © by Holt, Rinehart and Winston. All rights reserved.

Holt Science and Technology

12

Introduction to Plants

Back

Print

Name Class Date

Directed Reading A continued

FLOWERS

30. Why do some plants have flowers?

31. In a flower, modified leaves called 32. The broad, flat, thin leaflike parts of a flower, called

protect the bud.

, attract insects and other animals.

33. The male reproductive structure of flowers is a(n) 34. In flowers, a(n)

.

is the female reproductive

structure.

35. If the egg is fertilized, the

develops into a fruit and develops into a seed.

the

36. List three ways that humans use flowers.

Copyright © by Holt, Rinehart and Winston. All rights reserved.

Holt Science and Technology

13

Introduction to Plants

Back

Print

Name Class Date

Directed Reading A continued

Match the labels to the illustration. Write the letters in the space provided.

A

B D C F G I H

E

J

______ 37. sepal ______38. petal ______39. ovary ______40. ovule ______41. anther ______42. pistil ______43. filament ______44. stigma ______45. style ______46. stamen

Copyright © by Holt, Rinehart and Winston. All rights reserved.

Holt Science and Technology

14

Introduction to Plants

Back

Print

Name Class Date

Skills Worksheet

Directed Reading A

Section: Photosynthesis

______1. Which gas is most important to plants? a. oxygen b. nitrogen c. carbon dioxide d. other gases

2. What is photosynthesis?

3. Plants make the sugar

from carbon dioxide and

water. CAPTURING LIGHT ENERGY

Match the labels to the parts of the drawing. Write the letters in the spaces provided.

A

B

______ 4. grana ______ 5. chloroplast

6. The pigment in plants that absorbs light energy is called

M AS 2 PL

.

7. Why are most plants green?

Copyright © by Holt, Rinehart and Winston. All rights reserved.

Holt Science and Technology

1

Plant Processes

Back

Print

Name Class Date

Directed Reading A continued

MAKING SUGAR

8. What happens to the light energy that is captured by chlorophyll?

9. When photosynthesis takes place the plant gives off

gas. GETTING ENERGY FROM SUGAR

10. Define cellular respiration.

11. Excess glucose is converted to another type of sugar called

or stored as GAS EXCHANGE

.

Match the correct definition with the correct term. Write the letter in the space provided.

______12. a waxy coating that protects the plant from water loss ______13. an opening in a leaf's epidermis ______14. "double doors" for a stoma ______15. the loss of water from leaves THE IMPORTANCE OF PHOTOSYNTHESIS

a. stoma b. transpiration c. cuticle d. guard cells

______16. The base of nearly all food chains on earth is formed by a. chemical energy. b. light energy. c. photosynthetic organisms. d. animals.

17. How do some animals get energy from plants indirectly?

Copyright © by Holt, Rinehart and Winston. All rights reserved.

Holt Science and Technology

2

Plant Processes

Back

Print

Name Class Date

Skills Worksheet

Directed Reading A

Section: Reproduction of Flowering Plants

______ 1. The largest and most diverse group of plants is a. prairie grasses. b. trees. c. flowering plants. d. shrubs. FERTILIZATION

Match the labels to the parts of the drawing. Write the letters in the spaces provided. Some labels may be used more than once.

G A B H C

D E F

I

J

______ 2. anther ______ 3. ovary ______ 4. ovule

______ 7. pollen tube ______ 8. sperm ______ 9. stigma ______10. style

______ 5. ovule containing egg ______ 6. pollen

11. When pollen is moved from anthers to stigmas,

takes place.

12. When sperm fuses with the egg inside an ovule,

takes place.

Copyright © by Holt, Rinehart and Winston. All rights reserved.

Holt Science and Technology

3

Plant Processes

Back

Print

Name Class Date

Directed Reading A continued

FROM FLOWER TO FRUIT 13. After fertilization takes place, the

develops into a

seed.

14. After fertilization takes place, the

becomes a fruit.

FROM SEED TO PLANT

15. What is a dormant seed?

16. Define the word germination.

17. What three things do seeds need in order to sprout?

OTHER METHODS OF REPRODUCTION

Match the correct definition with the correct term. Write the letter in the space provided.

______18. above-ground stems from which new plants can grow

______19. tiny plants that grow along the edges of a plant's leaves and fall off and grow on their own

a. plantlets b. tubers c. runners

______20. underground stems from which new plants can grow

Copyright © by Holt, Rinehart and Winston. All rights reserved.

Holt Science and Technology

4

Plant Processes

Back

Print

Name Class Date

Skills Worksheet

Directed Reading A

Section: Plant Responses to the Environment

1. Name three stimuli to which plants respond.

PLANT TROPISMS

2. What is a tropism?

3. What is a positive tropism?

4. What is a negative tropism?

For each description listed, write whether it is an example of a positive tropism or negative tropism.

5. plant growth in response to light 6. shoot growth in response to gravity 7. root growth in response to gravity

Copyright © by Holt, Rinehart and Winston. All rights reserved.

Holt Science and Technology

5

Plant Processes

Back

Print

Name Class Date

Directed Reading A continued

8. A change in the direction a plant grows that is caused by light is

called

.

9. Plant growth that changes in response to the direction of gravity is called

. SEASONAL RESPONSES

10. What would happen if a plant bloomed during a cold winter?

11. How do plants living in areas with cold winters detect the change in seasons?

12. Plants that flower when nights are long are called 13. Plants that flower when nights are short are called 14. What are the characteristics of evergreen trees?

. .

15. What are the characteristics of deciduous trees?

Copyright © by Holt, Rinehart and Winston. All rights reserved.

Holt Science and Technology

6

Plant Processes

Back

Print

Name Class Date

Directed Reading A continued

For each tree listed, write whether it is an evergreen tree or a deciduous tree.

16. maple 17. oak 18. pine 19. elm 20. holly 21. Explain why the leaves of some deciduous trees change color in the fall.

Copyright © by Holt, Rinehart and Winston. All rights reserved.

Holt Science and Technology

7

Plant Processes

Back

Print

Name Class Date

Skills Worksheet

Directed Reading A

Section: What Is an Animal?

______ 1. Natural bath sponges are the remains of a. plants. c. volcanic rocks. b. animals. d. sea grass. ANIMAL DIVERSITY ______ 2. Which list contains organisms that are NOT animals? a. feather stars, corals, sea fans b. fish, spiders, birds c. slugs, kangaroos, monkeys d. giraffes, grizzly bears, cactuses ______ 3. Of the known animal species, how many are vertebrates? a. about 10% c. about 25% b. less than 5% d. more than 30% ______ 4. Of all animal species, how many are beetles? a. about 10% c. about 25% b. less than 5% d. more than 30%

5. An animal with a backbone is called a(n) 6. Animals without backbones are called

. .

Look at the following list of animals. Decide if each animal is a vertebrate or an invertebrate. Write I if it is an invertebrate. Write V if it is a vertebrate.

______ 7. fish ______ 8. amphibian ______ 9. jellyfish ______10. reptile ______11. snail ______12. bird ______13. worm ______14. mammal

______15. insect

Copyright © by Holt, Rinehart and Winston. All rights reserved.

Holt Science and Technology

1

Animals and Behavior

Back

Print

Name Class Date

Directed Reading A continued

ANIMAL CHARACTERISTICS

16. Until about 200 years ago, most people thought sponges

were

17. All animals are

. , which means they are made of

many cells.

18. Animal cells are

, which means they have

a nucleus.

19. Unlike plant cells, animal cells do not have 20. Animal cells are surrounded only by 21. Almost all animals reproduce 22. Animals produce sex cells, which are called

. . . and

.

23. An organism at an early stage of development is called

a(n)

24. In

. , part of an organism breaks off and develops

as a new organism.

25. Collections of similar cells are called

.

26. A group of tissues that carry out a special function of the body is called

a(n)

.

27. What are three things that animals use movement for?

28. An organism that eats other organisms is called

a(n)

.

Copyright © by Holt, Rinehart and Winston. All rights reserved.

Holt Science and Technology

2

Animals and Behavior

Back

Print

Name Class Date

Skills Worksheet

Directed Reading A

Section: Animal Behavior

KINDS OF BEHAVIOR ______ 1. Behavior that doesn't depend on learning or experience is called a. migration behavior. b. territory behavior. c. innate behavior. d. learned behavior. ______ 2. Innate behaviors are inherited through a. learning. b. genes. c. colorful objects. d. predators. ______ 3. A newborn whale's ability to swim is an example of an innate behavior that a. is not present at birth. b. develops months or years after birth. c. is learned. d. is present at birth. ______ 4. A one-year-old baby's first steps are an example of an innate behavior that a. develops some time after birth. b. is present at birth. c. is learned. d. is tied to learning language.

5. Behavior that has been learned from experience or from observing other

animals is called SURVIVAL BEHAVIOR

behavior.

6. Name four behaviors that animals must use to survive.

7. Animals that eat other animals are called

.

Copyright © by Holt, Rinehart and Winston. All rights reserved.

Holt Science and Technology

3

Animals and Behavior

Back

Print

Name Class Date

Directed Reading A continued

8. The animals that are eaten are called

.

9. Give an example of an animal that can be both predator and prey. Explain how this works.

10. A(n)

is an area that is occupied by one animal or

by a group of animals that do not allow other members of the species to enter.

11. Claiming a territory allows animals to save

by

avoiding

.

12. What are three activities animals use their territory for?

13. Name three things animals defend from other animals.

14. Describe three defensive behaviors animals may use against other animals.

15. The special behaviors that animals use to help them find mates are referred

to as

. for survival. to their young.

16. Many young animals depend on their 17. Some adult birds bring

18. Adult killer whales spend years teaching their young how

to

.

Copyright © by Holt, Rinehart and Winston. All rights reserved.

Holt Science and Technology

4

Animals and Behavior

Back

Print

Name Class Date

Directed Reading A continued

SEASONAL BEHAVIOR

Match the correct description with the correct term. Write the letter in the space provided.

______19. hide from the cold by burrowing in the mud ______20. store food to prepare for the winter ______21. migrate to central Mexico to wait for the spring ______22. fly south thousands of kilometers for the winter ______23. hibernate to deal with winter food and water shortages ______24. estivate to deal with summer food and water shortages

25. To

a. birds in the Northern Hemisphere b. mice, squirrels, and skunks c. frogs d. monarch butterflies e. desert squirrels and desert mice f. squirrels

is to travel from one place to another.

26. What are four reasons animals may migrate?

27. Fixed objects that animals use to find their way along migration paths are

called

28. Hibernation is a period of

. and decreased that some animals experience in winter.

29. Hibernating animals survive on stored

.

Copyright © by Holt, Rinehart and Winston. All rights reserved.

Holt Science and Technology

5

Animals and Behavior

Back

Print

Name Class Date

Directed Reading A continued

30. Describe what happens to an animal's body during hibernation.

31. Do bears hibernate? Explain your answer.

32. A period of reduced activity that some animals undergo in the summer is

called

.

33. Give two reasons why animals need to keep track of time.

34. The internal control of an animal's natural cycles is called

a(n)

.

35. What are two clues animals may use to set their internal clocks?

36. Some animals have biological clocks that keep track of daily cycles

called

.

37. Describe two behaviors that are controlled by seasonal cycles.

Copyright © by Holt, Rinehart and Winston. All rights reserved.

Holt Science and Technology

6

Animals and Behavior

Back

Print

Name Class Date

Skills Worksheet

Directed Reading A

Section: Social Relationships

1. When animals of the same species interact with each other, this behavior is

called

2. Animals depend on

. for their social interactions.

COMMUNICATION

3. Humans use 4. In communication, a(n)

to communicate. travels from one animal

to another.

5. Describe six reasons why animals may communicate.

WAYS TO COMMUNICATE

6. Animals communicate specific information to other animals through

, , and

, .

Copyright © by Holt, Rinehart and Winston. All rights reserved.

Holt Science and Technology

7

Animals and Behavior

Back

Print

Name Class Date

Directed Reading A continued

Match the animal with the way it uses sound to communicate.

______ 7. sing songs in the spring to claim their territory or to attract mates ______ 8. sing songs to tell other members of their species where they are ______ 9. use whistles and complex clicking noises to communicate with other members of their species ______10. howl to defend their territory from other members of their species ______11. use low frequency rumbles to tell other members of their species where they are

12. What is one advantage of using sound to communicate?

a. wolves b. dolphins c. male birds d. elephants e. humpback whales

13. Why do chimpanzees groom each other?

14. The chemicals that animals use to communicate are called

.

15. Ants

a variety of pheromones, such as that can warn other ants of danger and that announce which colony an ant belongs to.

16. Many animals use pheromones to find a(n) 17. When we smile at someone, we are using

. to send

a visual message.

Copyright © by Holt, Rinehart and Winston. All rights reserved.

Holt Science and Technology

8

Animals and Behavior

Back

Print

Name Class Date

Directed Reading A continued

18. List three ways animals may use body language to communicate a message.

LIVING TOGETHER

19. A group of lions is called a(n)

.

20. What are three advantages animals have when they live in a group?

21. Animals living in a group must compete with each other for

and

.

22. How do animals that live in a group deal with an insufficient supply of food in a particular area?

23. Animals that live in groups often attract

.

Copyright © by Holt, Rinehart and Winston. All rights reserved.

Holt Science and Technology

9

Animals and Behavior

Back

Print

Name Class Date

Skills Worksheet

Directed Reading A

Section: Simple Invertebrates

1. Animals without backbones are known as 2. How many invertebrates have been named?

.

3. How many invertebrates remain to be discovered?

INVERTEBRATE CHARACTERISTICS

______ 4. Which of these is an invertebrate? a. grasshopper c. man b. cow d. whale 5. Some invertebrates eat food through their mouths. Others absorb food

through their

.

6. Invertebrates have three basic body plans, or types of

.

7. List the three basic body plans for invertebrates.

8. List two functions of nerves.

Match the correct definition with the correct term. Write the letter in the space provided. Some terms will not be used.

______ 9. a pouch where food is digested

a. ganglion b. heart c. gut d. lung e. coelem

______10. the body cavity that surrounds the gut ______11. a concentrated mass of nerve cells

Copyright © by Holt, Rinehart and Winston. All rights reserved.

Holt Science and Technology

1

Invertebrates

Back

Print

Name Class Date

Directed Reading A continued

SPONGES

12. Explain why sponges are considered to be animals and not plants.

13. Describe the special way sponges bring oxygen and food into their bodies.

14. If part of a sponge breaks off, the sponge can 15. Among invertebrates, only sponges can use broken body parts

.

to

.

Match the correct description with the correct term. Write the letter in the space provided.

______16. allow water to flow into a sponge ______ 17. filter and digest foods ______18. make up a sponge's skeleton ______19. allows water to leave a sponge CNIDARIANS

a. osculum b. spicules c. pores d. collar cells

______20. Which of these traits defines cnidarians as a group? a. have a gut c. have stinging cells b. have nerves d. can regenerate

21. List the two body forms that cnidarians can have.

22. List two ways cnidarians use their stinging cells.

Copyright © by Holt, Rinehart and Winston. All rights reserved.

Holt Science and Technology

2

Invertebrates

Back

Print

Name Class Date

Directed Reading A continued

For each cnidarian listed, write whether it spends most of its life as a polyp or as a medusa.

23. jellyfish 24. hydrozoan 25. sea anemone 26. What kind of polyps build massive underwater reefs?

FLATWORMS ______ 27. What distinguishes flatworms from other kinds of worms? a. They are the most round. c. They are parasites. b. They are the simplest. d. They are planarians.

28. List the three major types of flatworms.

29. All flatworms have

symmetry.

30. The bumps on the sides of a flatworm's head are known as

.

31. Flukes and tapeworms are

, which means they feed

on the bodies of living organisms.

Match the correct description with the correct term. Write the letter in the space provided.

______32. parasites with special suckers and hooks ______33. predators with sensory lobes ______34. parasites that absorb food without a gut

a. planarians b. flukes c. tapeworms

Copyright © by Holt, Rinehart and Winston. All rights reserved.

Holt Science and Technology

3

Invertebrates

Back

Print

Name Class Date

Directed Reading A continued

ROUNDWORMS ______35. Which of these items is shaped like a roundworm's body? a. a banana b. a ruler c. a piece of spaghetti d. a spoon ______36. How many roundworms can live in a single apple? a. 100 b. 1,000 c. 100,000 d. 1,000,000 ______ 37. Which of these can be caused by eating meat infected with a roundworm? a. hydrozoans b. trichinosis c. flukes d. regeneration

38. Some roundworms cause disease. But some roundworms can be helpful. List a way that some roundworms are helpful.

Copyright © by Holt, Rinehart and Winston. All rights reserved.

Holt Science and Technology

4

Invertebrates

Back

Print

Name Class Date

Skills Worksheet

Directed Reading A

Section: Mollusks and Annelid Worms

______ 1. Which of these worms is sometimes seen on the sidewalk after it rains? a. flatworms c. earthworms b. roundworms d. tapeworms

MOLLUSKS

Match the correct definition with the correct term. Write the letter in the space provided. Some terms will not be used.

______ 2. squids and octopuses ______ 3. shellfish with two shells ______ 4. slugs and snails

a. gastropods b. cephalopods c. bivalves d. annelids

Match the correct description with the correct term. Write the letter in the space provided.

______ 5. use tentacles to grab food ______ 6. use gills to filter food ______ 7. use a radula to scrape food 8. All mollusks have complex

a. snails and slugs b. octopuses and squids c. clams and oysters

to control breathing,

movement, and digestion.

9. Octopuses and squids have the most advanced

of

all invertebrates.

10. Briefly describe an open circulatory system.

11. Briefly describe a closed circulatory system.

Copyright © by Holt, Rinehart and Winston. All rights reserved.

Holt Science and Technology

5

Invertebrates

Back

Print

Name Class Date

Directed Reading A continued

12. Most mollusks have open circulatory systems. List two mollusks that have closed circulatory systems.

Match the correct definition with the correct term. Write the letter in the space provided.

______13. helps the animal move ______14. includes the gills, guts, and other organs ______15. a layer of tissue that covers the visceral mass ______16. protects some mollusks from predators ANNELID WORMS

17. Annelid worms are often called

a. mantle b. shell c. foot d. visceral mass

worms.

18. List two ways that annelids are more complex than other worms.

19. How many segments do earthworms have?

20. Explain how earthworms can help gardeners.

21. What are marine worms covered with?

Copyright © by Holt, Rinehart and Winston. All rights reserved.

Holt Science and Technology

6

Invertebrates

Back

Print

Name Class Date

Directed Reading A continued

22. What are the three kinds of leeches, and what does each eat?

23. Explain how leeches can be helpful to doctors.

Match the correct description with the correct term. Write the letter in the space provided.

______24. means "many bristles" ______25. most live in the ocean ______26. have many segments ______ 27. can be or parasites, predators, or scavengers

a. leeches b. marine worms c. earthworms d. polychaetes

Copyright © by Holt, Rinehart and Winston. All rights reserved.

Holt Science and Technology

7

Invertebrates

Back

Print

Name Class Date

Skills Worksheet

Directed Reading A

Section: Arthropods

______ 1. Which of these statements best describes arthropods? a. They are insects. b. They are the largest group of animals. c. They are not specialized. d. There are very few species. CHARACTERISTICS OF ARTHROPODS

2. What are the four characteristics that all arthropods share?

3. List the three main body parts of an arthropod.

4. Arthro means "joint." What does pod mean?

5. Arthropods have a hard outer covering known as a(n)

.

6. The arthropod's skeleton supports its body and allows it to

.

7. List two things an exoskeleton does that an internal skeleton does not do as well.

8. All arthropods have a head and a well-developed

.

Copyright © by Holt, Rinehart and Winston. All rights reserved.

Holt Science and Technology

8

Invertebrates

Back

Print

Name Class Date

Directed Reading A continued

9. Briefly explain the difference between simple and compound eyes.

KINDS OF ARTHROPODS ______10. How are arthropods categorized? a. by their sense organs b. by the kinds of body parts they have c. by their number of legs d. by their shells

11. A feeler that senses touch, taste, or smell is known as a(n)

.

12. List three sense organs that an arthropod might have.

Match the correct definition with the correct term. Write the letter in the space provided.

______13. have two pairs of antennae, gills, and eyes on eyestalks ______14. have a cephalothorax, an abdomen, and clawlike mouthparts ______15. have three main body parts, six legs, and one pair of antennae ______16. have mandibles, one pair of antennae, and many legs 17. How might you tell a millipede from a centipede?

a. centipedes and millipedes b. crustaceans c. arachnids d. insects

18. What makes crustaceans different from other arthropods?

Copyright © by Holt, Rinehart and Winston. All rights reserved.

Holt Science and Technology

9

Invertebrates

Back

Print

Name Class Date

Directed Reading A continued

19. What do arachnids have instead of mandibles?

THE WORLD OF INSECTS

20. What are the three parts of an insect's body.

21. Insects develop and change form through the process of

.

Listed below are the stages of a butterfly's metamorphosis. Place them in the correct order from 1 to 5.

______22. a caterpillar becomes a pupa ______23. a larva hatches ______24. adult body parts replace larval body parts ______25. an adult lays eggs ______26. an adult pumps blood into its wings

27. Grasshoppers don't undergo complete metamorphosis. They undergo

.

28. A nymph sheds its exoskeleton through the process of

.

Copyright © by Holt, Rinehart and Winston. All rights reserved.

Holt Science and Technology

10

Invertebrates

Back

Print

Name Class Date

Skills Worksheet

Directed Reading A

Section: Echinoderms

1. Spiny invertebrates that live in the ocean are called 2. What are three examples of echinoderms?

.

SPINY SKINNED

3. An echinoderm's internal skeleton is called a(n) 4. Describe two kinds of echinoderm spine

.

BILATERAL OR RADIAL?

5. Adult echinoderms have 6. Adult echinoderms develop from larvae that have

symmetry.

symmetry. THE NERVOUS SYSTEM ______ 7. Which word best describes an echinoderm's nervous system? a. bilateral c. complex b. unique d. simple

8. The circle of nerve fibers around an echinoderm's mouth is called

a(n)

.

9. The movements of a sea star's arms are controlled by

a(n) WATER VASCULAR SYSTEM

.

10. List four things that the water vascular system helps echinoderms to do.

Copyright © by Holt, Rinehart and Winston. All rights reserved.

Holt Science and Technology

11

Invertebrates

Back

Print

Name Class Date

Directed Reading A continued

The five steps below describe how the sea star's water vascular system works. Place them in the correct order from 1 to 5.

______11. An ampulla controls fluid pressure. ______12. Radial canals connect to tube feet. ______13. Water enters through the sieve plate. ______14. Water flows into radial canals. ______15. Water flows to the ring canal. KINDS OF ECHINODERMS

Match the correct definition with the correct term. Write the letter in the space provided.

______16. round, with shell-like endoskeletons ______ 17. have a wormlike shape ______18. have long, slim arms ______19. have many feathery arms

a. brittle stars and basket stars b. sea urchins and sand dollars c. sea lilies and feather stars d. sea cucumbers

Copyright © by Holt, Rinehart and Winston. All rights reserved.

Holt Science and Technology

12

Invertebrates

Back

Print

Name Class Date

Skills Worksheet

Directed Reading A

Section: Fishes: The First Vertebrates

1. What are animals that have a backbone called?

CHORDATES ______ 2. Which of the following is NOT a group of chordates? a. notochords c. vertebrates b. lancelets d. tunicates

3. What is the largest group of chordates?

4. The four body parts that all chordates have at some point in their life are a pharyngeal pouch, a hollow nerve chord, a notochord, and a

. VERTEBRATE CHARACTERISTICS

5. The bones that interlock to form a column to surround and protect the spinal

cord are called

.

6. The tough material that the flexible parts of our ears and nose are made of is

called

.

7. According to fossil records, what were the first vertebrates on Earth?

ARE VERTEBRATES WARM OR COLD?

8. Warmblooded animals, or

, are animals that can use

energy released by the chemical reactions in their cells to warm their bodies.

9. Coldblooded animals that must depend on their surroundings to stay warm

are called

.

10. Are birds endotherms or ectotherms?

Copyright © by Holt, Rinehart and Winston. All rights reserved.

Holt Science and Technology

1

Fishes, Amphibians, and Reptiles

Back

Print

Name Class Date

Directed Reading A continued

FISH CHARACTERISTICS

Match the correct definition with the correct term. Write the letter in the space provided. Some terms will not be used.

______11. fan-shaped structures that help fishes move ______12. bony structures that protect the body of a fish ______13. a row or rows of tiny sense organs that detect water vibrations ______14. an organ that removes oxygen from the water

15. Fishes use

a. scales b. fertilization c. lateral line d. gill e. fins f. notochord

to steer, stop, and balance.

16. What organ is responsible for removing carbon dioxide from the blood of a fish?

17. By what method do most fishes reproduce?

KINDS OF FISHES ______18. How many different classes of fishes living today are there? a. two c. four b. three d. five ______19. This class of fishes has smooth, slimy skin, a skeleton made of cartilage, and a round, jawless mouth. a. jawless fishes c. cartilaginous fishes b. bony fishes d. extinct fishes ______20. Lampreys and hagfish belong to what class of fishes? a. jawless fishes c. cartilaginous fishes b. bony fishes d. extinct fishes ______21. What class of fishes has fully functional jaws, and are strong swimmers and expert predators? a. jawless fishes c. cartilaginous fishes b. bony fishes d. extinct fishes ______22. Sharks, skates, and rays belong to what class of fishes? a. jawless fishes c. cartilaginous fishes b. bony fishes d. extinct fishes

Copyright © by Holt, Rinehart and Winston. All rights reserved.

Holt Science and Technology

2

Fishes, Amphibians, and Reptiles

Back

Print

Name Class Date

Directed Reading A continued

______23. This class of fishes store oil in their livers to help them stay afloat. a. jawless fishes c. cartilaginous fishes b. bony fishes d. extinct fishes ______24. Ninety-five percent of all fishes belong to which class? a. jawless fishes c. cartilaginous fishes b. bony fishes d. extinct fishes ______25. What class of fishes has a skeleton made of bone and bodies covered by bony scales? a. jawless fishes c. cartilaginous fishes b. bony fishes d. extinct fishes ______26. This class of fishes can rest in one place without swimming. a. jawless fishes c. cartilaginous fishes b. bony fishes d. extinct fishes ______ 27. What is the name for the balloonlike organ in bony fishes that is filled with oxygen and other gases? a. gill c. lateral line system b. lobe d. swim bladder ______28. Lobe-finned fishes and ray-finned fishes belong to which class? a. jawless fishes c. cartilaginous fishes b. bony fishes d. sharks ______29. Lungfishes belong to which class? a. jawless fishes c. cartilaginous fishes b. bony fishes d. sharks

Copyright © by Holt, Rinehart and Winston. All rights reserved.

Holt Science and Technology

3

Fishes, Amphibians, and Reptiles

Back

Print

Name Class Date

Skills Worksheet

Directed Reading A

Section: Amphibians

MOVING TO LAND

1. What is an animal that has lungs and legs and can live in water called?

2. What animal do scientists think amphibians evolved from?

3. A saclike organ that takes oxygen from the air and delivers it to the blood is

called a(n) CHARACTERISTICS OF AMPHIBIANS

.

4. What does the word amphibian mean?

5. Why do most amphibians live in water or in damp areas?

6. What are the two ways in which many amphibians can breathe?

7. What characteristic of some amphibians can warn away predators?

8. An immature frog or toad that must live in the water after hatching to survive

is called a(n)

.

9. Most amphibians change as they grow. The change from an immature form to

an adult form is called

.

Copyright © by Holt, Rinehart and Winston. All rights reserved.

Holt Science and Technology

4

Fishes, Amphibians, and Reptiles

Back

Print

Name Class Date

Directed Reading A continued

KINDS OF AMPHIBIANS ______10. Which of the following are NOT amphibians? a. caecilians c. salamanders b. snakes d. frogs ______11. Which of the following traits do caecilians NOT have? a. legs c. bony scales b. thin, moist skin d. lungs ______12. In which continent do most salamanders live? a. Asia c. North America b. Africa d. South America ______13. Which of the following traits do frogs and toads NOT have? a. strong leg muscles c. well-developed vocal chords b. long, sticky tongues d. long tails

14. Which group of modern amphibians are most like prehistoric amphibians?

15. How does a frog's vocal sac affect the volume of the frog's song?

AMPHIBIANS AS ECOLOGICAL INDICATORS

16. Because amphibians are very sensitive to environmental changes, they are

sometimes called

.

17. Name three reasons why amphibians are sensitive to environmental changes.

Copyright © by Holt, Rinehart and Winston. All rights reserved.

Holt Science and Technology

5

Fishes, Amphibians, and Reptiles

Back

Print

Name Class Date

Skills Worksheet

Directed Reading A

Section: Reptiles

1. How are reptiles different from amphibians?

LIVING ON LAND

2. What animals moved to land and changed into reptiles?

3. What are the most well known prehistoric reptiles?

CHARACTERISTICS OF REPTILES

4. Name four factors that allow reptiles to live on land.

5. How does thick, dry skin help reptiles live on land?

6. Are most reptiles endotherms or ectotherms?

7. What is a reptile's most important adaptation to life on land?

Copyright © by Holt, Rinehart and Winston. All rights reserved.

Holt Science and Technology

6

Fishes, Amphibians, and Reptiles

Back

Print

Name Class Date

Directed Reading A continued

Match the correct definition with the correct term. Write the letter in the space provided.

______ 8. gives the embryo a rich supply of food ______ 9. provides the embryo with water and protein ______10. protects the egg from damage and keeps it from drying out ______11. surrounds and protects the embryo with amniotic fluid ______12. stores the waste from the embryo and passes oxygen to the embryo

a. shell b. albumen c. amniotic sac d. yolk e. allantois

13. Do most reptiles reproduce by internal or external fertilization?

KINDS OF REPTILES

14. Name the four groups of reptiles that are alive today.

15. What is the main difference between turtles and tortoises?

16. What is the trait that makes turtles and tortoises unique among reptiles?

17. How can you tell the difference between an alligator and a crocodile?

18. What group of reptiles is most common today?

19. What are two differences between tuataras and lizards?

Copyright © by Holt, Rinehart and Winston. All rights reserved.

Holt Science and Technology

7

Fishes, Amphibians, and Reptiles

Back

Print

Name Class Date

Skills Worksheet

Directed Reading A

Section: Characteristics of Birds

______ 1. Which characteristic do birds share with reptiles? a. horny beaks b. feet and legs covered with thick scales c. feathers and wings d. endothermic bodies FEATHERS ______ 2. Birds preen by a. spreading oil on their feathers. b. fluttering their feathers. c. shedding old feathers. d. growing new feathers.

3. The process of shedding old feathers and growing new is

called

.

4. Feathers that lie close to a bird's body and that keep it warm are

called

feathers.

5. Feathers on the outside of the bird's body that help it to fly and form its shape

are called HIGH-ENERGY ANIMALS

6. How do birds cool off?

feathers.

FAST DIGESTION

Match the correct description with the correct term. Write the letter in the space provided.

______ 7. This organ stores food after the bird swallows. ______ 8. This organ has small stones that grind the bird's food. ______ 9. This organ digests the food.

a. gizzard b. intestine c. crop

Copyright © by Holt, Rinehart and Winston. All rights reserved.

Holt Science and Technology

1

Birds and Mammals

Back

Print

Name Class Date

Directed Reading A continued

FLYING

10. List four adaptations that birds have for flight.

GETTING OFF THE GROUND

11. The upward force on a bird's wings when it is in flight is

called

12. A bird with

. wings can glide for long distances.

RAISING BABY BIRDS

13. Birds reproduce

by internal fertilization.

14. The act of sitting on eggs to keep them warm until they hatch is

called

.

Match the correct description with the correct term. Write the letter in the space provided.

______15. In some bird species, such as these, the parents divide the chore of nest-setting. ______16. In many species, including this one, the female sits on the nest and the male brings her food. ______ 17. This word describes birds that are active immediately after birth. ______18. This word describes birds that are weak and helpless immediately after birth.

a. precocial b. gulls c. altricial d. songbirds

Copyright © by Holt, Rinehart and Winston. All rights reserved.

Holt Science and Technology

2

Birds and Mammals

Back

Print

Name Class Date

Skills Worksheet

Directed Reading A

Section: Kinds of Birds

______ 1. About how many species of birds are on Earth? a. 10 b. 1,000 c. 100 d. 10,000 ______ 2. The largest order of all bird species includes a. flightless birds. b. water birds. c. songbirds. d. birds of prey. FLIGHTLESS BIRDS

3. Name two ways that flightless birds get around.

WATER BIRDS ______ 4. Which of the following birds is NOT a water bird? a. wood duck b. kiwi c. blue-footed booby d. common loon PERCHING BIRDS ______ 5. Perching birds include a large group known as a. songbirds. b. pelicans. c. cranes. d. swans.

Copyright © by Holt, Rinehart and Winston. All rights reserved.

Holt Science and Technology

3

Birds and Mammals

Back

Print

Name Class Date

Directed Reading A continued

6. What adaptation have perching birds developed?

7. What happens to a perching bird that falls asleep while resting on a tree branch?

BIRDS OF PREY

8. What are birds of prey?

9. List four different types of food that birds of prey eat.

10. What three adaptations allow birds of prey to be successful hunters?

Copyright © by Holt, Rinehart and Winston. All rights reserved.

Holt Science and Technology

4

Birds and Mammals

Back

Print

Name Class Date

Skills Worksheet

Directed Reading A

Section: Characteristics of Mammals

______ 1. About how many species of mammals are there in the modern world? a. 50 c. 5,000 b. 500 d. 5,000,000 THE FIRST MAMMALS ______ 2. What trait allowed early mammals to hunt food at night and to avoid being eaten by dinosaurs during the day? a. They had claws. b. They could swim. c. They were endotherms. d. They were birds. ______ 3. The first mammals that appeared more than 225 million years ago were about the size of a. mice. b. dogs. c. horses. d. elephants.

4. How did the end of the dinosaur era allow mammals to spread out and live in many different environments?

COMMON CHARACTERISTICS

5. What are the seven common characteristics of mammals?

Copyright © by Holt, Rinehart and Winston. All rights reserved.

Holt Science and Technology

5

Birds and Mammals

Back

Print

Name Class Date

Directed Reading A continued

6. What is the purpose of the mammary gland?

7. What is a diaphragm?

8. Name two benefits for mammals of being endotherms.

9. List three ways that mammals keep warm.

10. Name the specialized teeth that are important to meat-eating mammals.

11. What two types of specialized teeth are used by plant-eating mammals?

12. For how long do newborn mammals stay with at least one parent?

13. What is the advantage of mammals' large brains?

14. What senses do mammals use to find out about the world?

Copyright © by Holt, Rinehart and Winston. All rights reserved.

Holt Science and Technology

6

Birds and Mammals

Back

Print

Name Class Date

Skills Worksheet

Directed Reading A

Section: Placental Mammals

______ 1. Mammals are divided into groups based on how they a. are born. b. develop. c. breathe. d. sleep.

2. Name the three main groups of mammals.

3. A mammal whose embryos develop inside the mother's body is called

a(n)

mammal. . attaches the embryo to

4. Embryos grow inside an organ called the 5. An organ called the

the uterus.

6. The time it takes for an embryo to develop inside the mother's body is called

the

period.

ANTEATERS, ARMADILLOS, AND SLOTHS ______ 7. One characteristic that sets anteaters, armadillos, and sloths apart from other mammals is that they have a. no teeth. b. an armor-like shell. c. unique backbones with special connections between the vertebrae. d. unusual tails. INSECTIVORES

8. List three characteristics of insectivores.

Copyright © by Holt, Rinehart and Winston. All rights reserved.

Holt Science and Technology

7

Birds and Mammals

Back

Print

Name Class Date

Directed Reading A continued

RODENTS

9. Why do rodents have a set of strong incisors in their upper jaws?

RABBITS, HARES, AND PIKAS

10. How are rabbits, hares, and pikas similar to rodents?

11. Name two ways that rabbits, hares, and pikas are different from rodents.

FLYING MAMMALS

12. The only mammal that can fly is the 13. Define echolocation.

.

CARNIVORES

14. Carnivores are mammals that have large canine teeth and special molar teeth

for

. .

15. Fish-eating ocean carnivores are called

TRUNK-NOSED MAMMALS

16. The elephant's trunk is a combination of a(n)

and

a(n)

.

17. Name two uses for the elephant's trunk.

Copyright © by Holt, Rinehart and Winston. All rights reserved.

Holt Science and Technology

8

Birds and Mammals

Back

Print

Name Class Date

Directed Reading A continued

HOOFED MAMMALS

18. What is a hoof?

19. Name two characteristics of hoofed mammals.

CETACEANS ______20. Which of the following is NOT a cetacean? a. shark c. dolphin b. whale d. porpoise

21. How are cetaceans like bats?

MANATEES AND DUGONGS

22. What do manatees and dugongs use to swim?

23. What do manatees and dugongs eat?

PRIMATES

24. List five characteristics that make primates different from other mammals.

25. List two adaptations some primates have for living in trees.

Copyright © by Holt, Rinehart and Winston. All rights reserved.

Holt Science and Technology

9

Birds and Mammals

Back

Print

Name Class Date

Skills Worksheet

Directed Reading A

Section: Monotremes and Marsupials

MONOTREMES

Match the correct description with the correct term. Write the letter in the space provided.

______ 1. a mammal that lays eggs ______ 2. an egg-laying mammal with large claws and long snout ______ 3. an egg-laying mammal that lives in rivers and ponds

4. How does a platypus find food?

a. platypus b. monotreme c. echidna

MARSUPIALS

5. What is a marsupial?

6. How is the development of the marsupial young different from that of other mammals?

7. The only living marsupial that is native to North America is

the

.

8. How does a newborn marsupial get to its mother's pouch?

Copyright © by Holt, Rinehart and Winston. All rights reserved.

Holt Science and Technology

10

Birds and Mammals

Back

Print

Name Class Date

Directed Reading A continued

For each animal listed, write whether it is a marsupial or a monotreme.

9. koala 10. opossum 11. echidna 12. kangaroo 13. wallaby 14. numbat 15. platypus 16. List two reasons why many species of marsupials are becoming extinct in Australia.

17. How did the Tasmanian tiger become extinct?

Copyright © by Holt, Rinehart and Winston. All rights reserved.

Holt Science and Technology

11

Birds and Mammals

Back

Print

Name Class Date

Skills Worksheet

Directed Reading A

Section: Everything Is Connected

______ 1. What is one way alligators and other organisms interact? a. alligators dig holes b. alligators escape from heat c. alligators swim d. fish use holes dug by alligators STUDYING THE WEB OF LIFE

2. What is ecology?

3. What is the biotic part of the environment?

4. What is the abiotic part of the environment?

For each word listed, write whether it is from the biotic or abiotic part of the environment.

_______________________ 5. alligator _______________________ 6. gar _______________________ 7. temperature _______________________ 8. water _______________________ 9. plants _______________________ 10. rocks

Copyright © by Holt, Rinehart and Winston. All rights reserved.

Holt Science and Technology

1

Interactions of Living Things

Back

Print

Name Class Date

Directed Reading A continued

Put the five levels of environmental organization in order from smallest to largest. Write the appropriate number in the space provided.

______11. population ______12. biosphere ______13. individual organism ______14. ecosystem ______15. community

16. A group of seaside sparrows competing for food, nesting space, and

mates in a salt marsh is an example of the level of environmental organization.

17. List four species in the salt marsh community.

18. List three ways that species in the salt marsh community use cordgrass.

19. An ecosystem is made up of a community of organisms and the

parts of the environment, such as temperature, soil, and water.

20. The ocean, the air, and all areas of Earth where life is are all parts of the

level of organization.

Copyright © by Holt, Rinehart and Winston. All rights reserved.

Holt Science and Technology

2

Interactions of Living Things

Back

Print

Name Class Date

Skills Worksheet

Directed Reading A

Section: Living Things Need Energy

______ 1. To survive, living things need a. grasslands. b. energy. THE ENERGY CONNECTION

2. What three groups can animals be divided into based on how they get energy? c. clothing. d. species.

3. Organisms that use sunlight directly to make food are called

.

4. Producers use a process called

to make food.

5. Herbivores, carnivores, and omnivores that eat other organisms are known as

.

6. A consumer that eats only plants is a(n) 7. A consumer that eats only animals is a(n) 8. A consumer that eats both plants and animals is

. .

a(n)

. . .

9. An example of a herbivore is a(n) 10. An example of an omnivore is a(n) 11. Omnivores that eat dead plants and animals are called

.

12. Organisms that break down dead organisms to get energy are called

.

13. List two decomposers.

Copyright © by Holt, Rinehart and Winston. All rights reserved.

Holt Science and Technology

3

Interactions of Living Things

Back

Print

Name Class Date

Directed Reading A continued

14. A simple diagram that shows how energy in food flows from one organism to

another is a(n)

.

15. A food chain does not show energy connections in nature as accurately as a

food

does.

16. In food webs and food chains, does the arrow point toward the plant or animal doing the eating or the one that is eaten?

17. List the two main food webs on Earth.

18. Why isn't all of the energy that grass gets from sunlight passed on to the prairie dogs that eat the grass?

19. The diagram that shows an ecosystem's loss of energy at each level of the

food chain is known as WOLVES AND THE ENERGY PYRAMID

.

20. When gray wolves were wiped out as the wilderness was settled, what happened to the grass and elk in some areas?

Copyright © by Holt, Rinehart and Winston. All rights reserved.

Holt Science and Technology

4

Interactions of Living Things

Back

Print

Name Class Date

Directed Reading A continued

21. What effect does the U.S. Fish and Wildlife Service think the return of wolves will have in Yellowstone National Park?

22. Why are ranchers near Yellowstone worried about wolves returning?

23. How have three populations of organisms changed since the reestablishment of wolves in Yellowstone National Park?

Copyright © by Holt, Rinehart and Winston. All rights reserved.

Holt Science and Technology

5

Interactions of Living Things

Back

Print

Name Class Date

Skills Worksheet

Directed Reading A

Section: Types of Interactions

______ 1. In a natural community, population sizes vary because a. the populations are not affected by each other. b. the populations all affect one another. c. individuals in the populations decide to have big families. d. the populations are able to grow without stopping. INTERACTIONS WITH THE ENVIRONMENT

2. When a frog lays hundreds of eggs in a small pond, what happens to the population of frogs in the pond? Explain your answer.

3. A resource so scarce that it limits the size of a population is called

a(n)

.

4. In what way can food become a limiting factor?

5. The largest population that an environment can support is called its

.

6. What happens when a population grows larger than its carrying capacity?

INTERACTIONS BETWEEN ORGANISMS

7. Ecologists have listed four main ways that species and individuals affect

each other--competition, coevolution.

and prey, symbiosis, and

Copyright © by Holt, Rinehart and Winston. All rights reserved.

Holt Science and Technology

6

Interactions of Living Things

Back

Print

Name Class Date

Directed Reading A continued

COMPETITION

8. When two or more individuals or populations try to use the same resource,

it is called

.

9. Give an example of competition between individuals within a population and of competition between populations.

PREDATORS AND PREY ______10. What word is used for an organism that eats another organism? a. predator c. competitor b. carrier d. prey ______11. What word is used for an organism that is eaten? a. predator c. competitor b. carrier d. prey

12. List two adaptations predators use to catch prey.

13. List two ways prey have adapted to avoid predators.

14. Give two examples of animals using defensive chemicals against predators.

15. How can being bright red, yellow, or orange help an animal avoid predators?

SYMBIOSIS ______16. A close, long-term association between two or more species is called a. symbiosis. c. predator adaptations. b. defensive chemicals. d. camouflage.

Copyright © by Holt, Rinehart and Winston. All rights reserved.

Holt Science and Technology

7

Interactions of Living Things

Back

Print

Name Class Date

Directed Reading A continued

17. What are the three types of symbiosis?

18. Both organisms benefit in the type of symbiosis called

.

19. When one organism benefits and the other is unaffected, the symbiotic

relationship is called

.

20. A symbiotic relationship in which one organism benefits and the other is

harmed is called

.

21. In parasitism, the organism that benefits is called

the

.

22. The organism that is harmed by a parasite is called

the

.

23. Do most parasites kill their hosts? Why or why not?

COEVOLUTION

24. What name is given to a long-term change that takes place in two species because of their close interactions with one another? Give an example.

25. Describe an example of coevolution between a flower and its pollinator.

Copyright © by Holt, Rinehart and Winston. All rights reserved.

Holt Science and Technology

8

Interactions of Living Things

Back

Print

Name Class Date

Skills Worksheet

Directed Reading A

Section: The Cycles of Matter

THE WATER CYCLE

1. The movement of water between the oceans, atmosphere, land, and living

things is the

.

2. The changing of water from liquid to vapor is

called

3. During

. , water vapor cools and returns to a

liquid state

4. Water that falls from the atmosphere to the land and oceans

is called

.

5. Precipitation that falls on land and then flows into streams, rivers, and lakes

is called

.

6. Precipitation that seeps into the ground and is stored among rocks

is called

.

7. Water vapor is released by plants and returned to the environment

in a process called

.

8. Name three reasons water is needed for life on Earth.

THE CARBON CYCLE

______ 9. What are organic molecules? a. molecules that are alive b. water molecules ______10. How do animals get carbon? a. through photosynthesis b. by taking it from the air c. molecules that contain carbon d. molecules that break down c. through respiration d. by eating plants

______11. In what process is carbon returned to the environment? a. condensation c. respiration b. transpiration d. evaporation

Copyright © by Holt, Rinehart and Winston. All rights reserved.

Holt Science and Technology

1

Cycles in Nature

Back

Print

Name Class Date

Directed Reading A continued

12. What happens to carbon dioxide during photosynthesis?

13. What happens during decomposition?

14. What happens during combustion?

THE NITROGEN CYCLE

15. The movement of nitrogen between the environment and living things is

called the

.

16. The process in which bacteria in the soil change nitrogen gas into forms that

plants can use is called

17. Why do organisms need nitrogen?

.

18. Name two things that perform nitrogen fixation.

19. How do plants get the nitrogen they need?

20. How do animals get the nitrogen they need?

Copyright © by Holt, Rinehart and Winston. All rights reserved.

Holt Science and Technology

2

Cycles in Nature

Back

Print

Name Class Date

Directed Reading A continued

21. What happens to nitrogen during decomposition?

MANY CYCLES

______22. Which one of the following statements describes cycles in nature? a. They are all separate. b. Minerals do not cycle through Earth. c. Animals play no part in cycles. d. Each cycle is connected to others. 23. Give two examples of minerals that living cells need that pass through cycles.

Copyright © by Holt, Rinehart and Winston. All rights reserved.

Holt Science and Technology

3

Cycles in Nature

Back

Print

Name Class Date

Skills Worksheet

Directed Reading A

Section: Ecological Succession

1. What was the condition of most trees in Yellowstone National Park after the summer forest fires in 1988?

REGROWTH OF A FOREST

______ 2. After one year, the burned forest in Yellowstone National Park a. had barely changed. b. had begun to grow back. c. had completely grown back. d. was still completely destroyed. ______ 3. What is the meaning of succession? a. a forest growing back after a fire b. a forest being destroyed c. a community quickly growing back d. a community growing over time

PRIMARY SUCCESSION

4. The first organisms to start a process of

succession are called

.

5. The types of organisms that are usually the pioneer species in primary

succession are

6. Over time, the remains of

. add to the soil.

7. What is usually present in an area where primary succession begins?

8. How long does it take for an area of bare rock to become a forest?

Copyright © by Holt, Rinehart and Winston. All rights reserved.

Holt Science and Technology

4

Cycles in Nature

Back

Print

Name Class Date

Directed Reading A continued

SECONDARY SUCCESSION

______ 9. Secondary succession may occur in an area if a. no disturbances occur there for hundreds of years. b. soil is left intact after a major disturbance. c. a glacier retreats from the area. d. a farmer continually grows crops in the area. ______10. What is usually the first plant to grow in secondary succession? a. conifers c. crab grass b. crops d. horseweed ______11. In secondary succession, how long does it take for a forest to form? a. 5­15 years c. 250 years b. 100 years d. 1,000 years

MATURE COMMUNITIES AND BIODIVERSITY

______12. What is the meaning of a mature community? a. a forest that grows through primary succession b. a community with high biodiversity c. a desert that has many plants d. a community with organisms well adapted to the area 13. What is a climax species?

14. Why is biodiversity important to communities of organisms?

Copyright © by Holt, Rinehart and Winston. All rights reserved.

Holt Science and Technology

5

Cycles in Nature

Back

Print

Name Class Date

Skills Worksheet

Directed Reading A

Section: Land Biomes

THE EARTH'S LAND BIOMES

1. Features of an environment that are not alive, such as soil, water, and climate,

are

factors.

2. The living parts of an environment, plants and animals, are

factors.

3. A large area characterized by its climate and the plants and animals that live

there is a(n) FORESTS

.

4. Name the three main types of forest biomes.

5. Why do deciduous trees shed their leaves?

6. Forests made up of trees that keep their needle-shaped leaves year-round are

called

7. What are two traits of conifers?

forests.

8. What are the three functions of the waxy coating on conifer leaves?

Copyright © by Holt, Rinehart and Winston. All rights reserved.

Holt Science and Technology

1

The Earth's Ecosystems

Back

Print

Name Class Date

Directed Reading A continued

9. What are two reasons that few large plants grow beneath the trees of a coniferous forest?

10. Why do tropical rain forests have more biological diversity than other places on Earth?

11. Where do most animals live in the rain forest?

12. Where are most of the nutrients in a tropical rain forest?

GRASSLANDS

______13. Which is NOT a name for a grassland? a. steppe c. canopy b. prairie d. pampas ______14. What prevents temperate grasslands from having trees? a. too much rain c. deep roots b. grazing animals d. rolling hills ______15. A biome with clumps of trees and seasonal rains is a a. temperate grassland. c. desert. b. savanna. d. tropical rain forest. ______16. Which animal is NOT an example of a large herbivore that lives on the African savanna? a. zebra c. horse b. wildebeest d. elephant

DESERTS

______ 17. A region with few plants, little rain, and extreme temperatures is called a a. prairie. c. desert. b. grassland. d. savanna.

Copyright © by Holt, Rinehart and Winston. All rights reserved.

Holt Science and Technology

2

The Earth's Ecosystems

Back

Print

Name Class Date

Directed Reading A continued

18. Name four adaptations of desert plants.

Match the correct description with the correct term. Write the letter in the space provided.

______19. stores water from flowers under its shell ______20. recycles water from foods it eats ______21. huge ears get rid of body heat ______22. buries self in ground during dry season

a. jack rabbit b. spadefoot toad c. desert tortoise d. kangaroo rat

TUNDRA

23. A biome with very cold temperatures and little rainfall is called a(n)

.

24. The layer of soil in the polar tundra that is always frozen is called

.

25. Why are shallow-rooted plants, such as grasses and small shrubs, common in polar tundra?

26. What is the main way alpine tundra differs from arctic tundra?

27. Define the term tree line.

Copyright © by Holt, Rinehart and Winston. All rights reserved.

Holt Science and Technology

3

The Earth's Ecosystems

Back

Print

Name Class Date

Skills Worksheet

Directed Reading A

Section: Marine Ecosystems

1. Ecosystems in the ocean are called

.

LIFE IN THE OCEAN

2. What are the largest animals on Earth?

3. Tiny organisms that float near the surface of freshwater and marine

environments are called

4. How do plankton get their food?

.

TEMPERATURE

______ 5. How does the temperature of ocean water change as it gets deeper? a. It decreases. b. It increases. c. It does not change. d. It varies from day to day. ______ 6. Which ocean temperature zone has the warmest water? a. deep zone b. thermocline c. surface zone d. middle layer ______ 7. How does ocean temperature affect whales? a. They can only live in cold water. b. They can only live in warm water. c. They cannot stand sudden temperature changes. d. They migrate from cold to warm areas to reproduce.

Copyright © by Holt, Rinehart and Winston. All rights reserved.

Holt Science and Technology

4

The Earth's Ecosystems

Back

Print

Name Class Date

Directed Reading A continued

DEPTH AND SUNLIGHT

Match the correct description with the correct term. Write the letter in the space provided.

______ 8. warm water and a lot of sunlight; ocean floor starts to slope downward ______ 9. sea floor drops sharply; contains deep water of the open ocean ______10. ocean floor; deepest parts get no sunlight ______11. where the ocean meets the land; exposed to air part of the day

a. intertidal zone b. neritic zone c. oceanic zone d. benthic zone

A CLOSER LOOK

12. Name three ways life on Earth depends on the ocean.

13. Name three kinds of intertidal areas.

14. Name two ways certain organisms have adapted to living on rocky shores.

15. Name three marine organisms that live on coral reefs.

16. A place where fresh water from rivers mixes with salty ocean water is

a(n)

.

Copyright © by Holt, Rinehart and Winston. All rights reserved.

Holt Science and Technology

5

The Earth's Ecosystems

Back

Print

Name Class Date

Directed Reading A continued

17. Estuaries are rich in nutrients, so large numbers of

live there.

18. How do animals in the Sargasso Sea hide from predators?

19. Does the polar ice ecosystem support much life? Explain why or why not.

Copyright © by Holt, Rinehart and Winston. All rights reserved.

Holt Science and Technology

6

The Earth's Ecosystems

Back

Print

Name Class Date

Skills Worksheet

Directed Reading A

Section: Freshwater Ecosystems

STREAM AND RIVER ECOSYSTEMS

1. Name two places that water in rivers may come from.

2. A strong, wide stream is a(n) 3. A stream of water joining a larger stream is a(n)

. .

4. What is one important abiotic factor in freshwater ecosystems?

Match the correct description with the correct term. Write the letter in the space provided.

______ 5. attach to rocks ______ 6. live under rocks ______ 7. use suction disks

a. insects b. tadpoles c. algae and moss

POND AND LAKE ECOSYSTEMS

Match the correct description with the correct term. Write the letter in the space provided.

______ 8. zone that goes as deep as sunlight can reach; home to many photosynthetic plankton ______ 9. zone where no sunlight reaches; organisms feed on dead organisms from above ______10. zone closest to the edge of a lake or pond; sunlight reaches the bottom

a. deep-water zone b. open-water zone c. littoral zone

Copyright © by Holt, Rinehart and Winston. All rights reserved.

Holt Science and Technology

7

The Earth's Ecosystems

Back

Print

Name Class Date

Directed Reading A continued

11. What enables algae and plants to grow in the littoral zone?

12. Name three organisms that live in the deep-water zone.

WETLAND ECOSYSTEMS

Match the correct description with the correct term. Write the letter in the space provided.

______13. a wetland ecosystem with trees and vines ______14. an area of land sometimes underwater or with very moist soil ______15. a wetland ecosystem that has no trees but has other plants 16. Name three reasons wetlands are valuable.

a. wetland b. marsh c. swamp

17. Where are freshwater marshes often found?

18. Where are swamps found?

Copyright © by Holt, Rinehart and Winston. All rights reserved.

Holt Science and Technology

8

The Earth's Ecosystems

Back

Print

Name Class Date

Directed Reading A continued

FROM A LAKE TO A FOREST

______19. What happens when plants and animals at the bottom of a lake decompose? a. Animal life in the lake increases. b. The lake has more water. c. Oxygen is lost, affecting the animals that live in the lake. d. Living conditions for fish improve. ______20. How does a lake start to become a forest? a. Plants grow closer to the center of the lake. b. Sediment and leaves settle at the bottom of the lake. c. The lake becomes a swamp. d. Fishes die off due to lack of oxygen.

Copyright © by Holt, Rinehart and Winston. All rights reserved.

Holt Science and Technology

9

The Earth's Ecosystems

Back

Print

Name Class Date

Skills Worksheet

Directed Reading A

Section: Environmental Problems

1. What happened in the late 1700s that caused more harmful substances to enter the air, water, and soil?

POLLUTION ______ 2. An unwanted change in the environment caused by harmful substances, gases, wastes, radiation, or noise is a. overpopulation. c. pollution. b. biodiversity. d. landfill.

______ 3. Something that causes pollution is called a a. resource. c. change. b. pollutant. d. substance. ______ 4. Pollutants can be natural, or they can be a. unusual. c. harmful. b. renewable. d. human-made.

______ 5. What does the average American throw away more of than the average person in any other nation? a. plants c. animals b. trash d. oil ______ 6. Wastes that can catch fire, wear through metal, explode, or make people sick are called a. harmful wastes. c. hazardous wastes. b. dangerous wastes. d. critical wastes.

______ 7. Which of these are hazardous wastes? a. leftovers c. medical wastes b. lawn clippings d. newspapers 8. What are some ways that chemicals are useful to people?

Copyright © by Holt, Rinehart and Winston. All rights reserved.

Holt Science and Technology

1

Environmental Problems and Solutions

Back

Print

Name Class Date

Directed Reading A continued

9. Describe two groups of harmful chemicals and their effects.

10. Nuclear power plants produce

, which give off

dangerous radiation.

11. What in the atmosphere has increased since the Industrial Revolution?

12. What do many scientists believe has happened as the amount of carbon dioxide in the atmosphere has increased?

13. What effect could the rise in global temperatures have on the world's oceans?

14. How is noise pollution harmful?

RESOURCE DEPLETION

Match the correct description with the correct term. Write the letter in the space provided.

______15. A resource that can be used over and over, or that can be replaced is a(n) a. renewable resource. c. mineral or fossil fuel. b. nonrenewable resource. d. exhaustible resource. ______16. A resource that cannot be replaced, or is replaced over thousands or millions of years is a a. renewable resource. c. wind energy resource. b. nonrenewable resource. d. timber resource.

Copyright © by Holt, Rinehart and Winston. All rights reserved.

Holt Science and Technology

2

Environmental Problems and Solutions

Back

Print

Name Class Date

Directed Reading A continued

______ 17. What is true about using oil or coal for energy? a. Coal and oil will last forever. b. Coal and oil may eventually run out. c. Coal and oil help the environment. d. Coal and oil will become easier to find.

______18. What might happen in areas where fresh water is used faster than it is replaced? a. Plants and animals will survive without water. b. People might drink less water. c. The areas might run out of fresh water. d. There might be no change in the areas. EXOTIC SPECIES

19. What is an exotic species?

20. Describe how exotic species might be moved from one part of the world to another.

HUMAN POPULATION GROWTH ______21. What advances have made human population growth possible? a. advances in housing and education b. advances in radio and television c. advances in medicine and farming d. advances in farming and housing ______22. What word describes the presence of too many individuals in an area for the available resources? a. overpopulation c. excessiveness b. crowding d. biodiversity HABITAT DESTRUCTION

23. The place where an organism lives is its

.

24. The number and variety of organisms in a given area during a specific period

of time is

.

Copyright © by Holt, Rinehart and Winston. All rights reserved.

Holt Science and Technology

3

Environmental Problems and Solutions

Back

Print

Name Class Date

Directed Reading A continued

25. What is the effect of habitat damage or destruction on biodiversity?

26. The clearing of forest lands is known as

.

27. Describe one way deforestation is harmful to tropical rain forest habitats.

28. An oil spill is one example of

pollution in a

marine habitat.

29. Water pollution that comes from many sources is called

pollution.

30. How do plastics harm water habitats?

EFFECTS ON HUMANS

31. Describe how water pollution can harm humans.

32. Describe how air pollution can harm humans.

33. What is a possible long-term effect of exposure to some chemicals?

Copyright © by Holt, Rinehart and Winston. All rights reserved.

Holt Science and Technology

4

Environmental Problems and Solutions

Back

Print

Name Class Date

Skills Worksheet

Directed Reading A

Section: Environmental Solutions

1. List four human needs that will have an impact on the Earth.

CONSERVATION ______ 2. The preservation and wise use of natural resources is called a. recycling. c. conservation. b. biodiversity. d. ecology. ______ 3. Riding a bike not only saves fuel, it can also help prevent a. air pollution. c. soil pollution. b. water pollution. d. overpopulation. ______ 4. When people practice conservation, they use fewer a. muscles. c. natural resources. b. foods. d. habitats. ______ 5. Which of the following is NOT one of the three Rs of conservation? a. reuse c. reduce b. recycle d. rebuild REDUCE

6. In some countries, as much as much as one-third of the waste produced is made up of what?

7. Something that is

can be broken down by living

organisms.

8. Describe how some farmers are taking better care of the environment.

Copyright © by Holt, Rinehart and Winston. All rights reserved.

Holt Science and Technology

5

Environmental Problems and Solutions

Back

Print

Name Class Date

Directed Reading A continued

9. What are some new sources of energy being studied in the hopes that they will replace fossil fuels?

10. What have car companies developed that will reduce the need for fossil fuels as well as pollution?

REUSE

11. What is one way plastic bags can be reused?

12. What are two ways old tires can be reused?

13. How is water reclaimed and reused?

RECYCLE ______14. Recovering valuable or useful materials from waste or scrap is called a. reusing. c. renewing. b. reducing. d. recycling. ______15. What can be recycled into a natural fertilizer? a. old tires c. yard clippings b. old plastics d. aluminum cans ______16. What percentage of energy needed to change raw ore into aluminum is saved by recycling aluminum? a. 95% c. 16% b. 75% d. 100%

Copyright © by Holt, Rinehart and Winston. All rights reserved.

Holt Science and Technology

6

Environmental Problems and Solutions

Back

Print

Name Class Date

Directed Reading A continued

______ 17. An example of resource recovery includes using garbage to a. generate electricity. c. limit trash collection. b. reduce air pollution. d. save trees. 18. List three materials that can be recycled, and describe how one of them is used again.

19. How do some communities make recycling easy for citizens?

20. Why are some people concerned about burning waste material to produce energy?

MAINTAINING BIODIVERSITY

21. Why is biodiversity important to an ecosystem?

22. Describe what might happen if an important predator in an ecosystem were lost.

Copyright © by Holt, Rinehart and Winston. All rights reserved.

Holt Science and Technology

7

Environmental Problems and Solutions

Back

Print

Name Class Date

Directed Reading A continued

23. How does the Endangered Species Act help protect biodiversity?

24. What is one example of an animal that has been helped by the Endangered Species Act?

25. Why is it important to protect habitats and not just individual species of organisms?

ENVIRONMENTAL STRATEGIES

26. What does the EPA do to help protect the environment?

27. List five environmental strategies that people can use to help protect Earth's environment.

28. List five things that young people can do to help clean up Earth.

Copyright © by Holt, Rinehart and Winston. All rights reserved.

Holt Science and Technology

8

Environmental Problems and Solutions

Back

Print

Name Class Date

Skills Worksheet

Directed Reading A

Section: Body Organization

1. The maintenance of a stable internal environment in the body is

. CELLS, TISSUES, AND ORGANS ______ 2. What is a collection of tissues that work together to carry out a specialized function in the body? a. a cell c. an organ b. connective tissue d. a team ______ 3. Muscle tissue helps your stomach digest food by a. protecting the stomach. c. breaking up food. b. supplying oxygen. d. producing acids.

4. What can happen to cells if homeostasis is disrupted?

5. How is your body like a soccer team?

6. A group of similar cells working together forms

a(n)

.

Match the correct description with the correct term. Write the letter in the space provided.

______ 7. joins, supports, and insulates organs

a. nervous tissue b. muscle tissue c. epithelial tissue d. connective tissue

______ 8. covers and protects underlying tissue ______ 9. sends electrical signals through the body ______10. produces movement

Copyright © by Holt, Rinehart and Winston. All rights reserved.

Holt Science and Technology

1

Body Organization and Structure

Back

Print

Name Class Date

Directed Reading A continued

11. How does your body know when your stomach is full?

12. The wall of the stomach contains blood and another

called collagen.

13. The inside of your stomach is lined with 14. Organs that work together make up a(n)

. .

WORKING TOGETHER

Match the correct description with the correct term. Write the letter in the space provided.

______15. includes the heart and blood vessels ______16. removes wastes from blood ______ 17. sends out chemical messages ______18. includes skin, hair, and nails ______19. includes the heart, blood vessels, and blood ______20. supports and protects body parts ______21. helps get rid of bacteria and viruses ______22. absorbs oxygen through the lungs ______23. breaks down food into nutrients ______24. helps the body move ______25. produces eggs and protects the fetus ______26. sends and receives electrical messages throughout the body

a. integumentary system b. muscular system c. skeletal system d. cardiovascular system e. respiratory system f. urinary system g. circulatory system h. female reproductive system i. nervous system j. digestive system k. lymphatic system l. endocrine system

27. How do organ systems work together to maintain homeostasis? Give an example.

Copyright © by Holt, Rinehart and Winston. All rights reserved.

Holt Science and Technology

2

Body Organization and Structure

Back

Print

Name Class Date

Skills Worksheet

Directed Reading A

Section: The Skeletal System

1. Your skeletal system is made up of

, that holds

, and the bones together. BONES

______ 2. When you were born, most of your skeleton was made of a. compact bone. c. spongy bone. b. cartilage. d. osteoblasts. ______ 3. What are two parts of your body that are made out of cartilage? a. hair and nails b. ear lobes and jaw bone c. teeth and gums d. end of nose and top of ear

4. What are the four functions of the skeletal system?

5. Your heart and lungs are protected by

, your spinal , and your brain is protected

cord is protected by by the

6. Bones store

. .

7. Some of your bones are filled with a special material called

, which makes blood cells.

8. The minerals found in bones are deposited by living cells

called

.

Copyright © by Holt, Rinehart and Winston. All rights reserved.

Holt Science and Technology

3

Body Organization and Structure

Back

Print

Name Class Date

Directed Reading A continued

Identify the type of bone tissue to which each of the following descriptions relates. Write compact bone or spongy bone in the space provided.

9. It has many open spaces. 10. It is rigid and dense. 11. It contains small blood vessels. 12. It provides most of the strength for bones. 13. Compare red bone marrow and yellow bone marrow.

JOINTS

Match the correct description with the correct term. Write the letter in the space provided.

______14. allows little or no movement ______15. allows movement in all directions ______16. allows you to flex and extend ______ 17. cushions the area where bones meet ______18. where two or more bones meet ______19. connective tissue that connects the bones in a joint ______20. the type of joint found in the hand and wrist SKELETAL SYSTEM INJURIES AND DISEASES

a. gliding joint b. ligaments c. fixed joint d. joint e. hinge joint f. ball-and-socket joint g. cartilage

21. Explain how parts of the skeletal system may become injured.

22. A disease that causes bones to become less dense is

called

.

23. A disease that may cause joints to swell or stiffen is

called

Holt Science and Technology

.

4

Body Organization and Structure

Copyright © by Holt, Rinehart and Winston. All rights reserved.

Back

Print

Name Class Date

Skills Worksheet

Directed Reading A

Section: The Muscular System

1. Why is it impossible to sit still, without moving any muscles at all?

KINDS OF MUSCLE

Match the correct description with the correct term. Write the letter in the space provided.

______ 2. found in your heart and pumps blood around your body ______ 3. enables your bones to move ______ 4. found in the digestive tract and in the walls of blood vessels

5. Muscle action that is under your control is 6. Muscle action that is not under your control is

a. smooth muscle b. cardiac muscle c. skeletal muscle

. .

MOVEMENT

7. What happens in your body when you want to move?

8. Tendons are strands of connective tissue that connect your

to your

9. A muscle that bends part of your body is called

.

a(n)

.

10. A muscle that straightens part of your body is called

a(n)

11. When your arm bends, the

. muscle is the flexor.

Copyright © by Holt, Rinehart and Winston. All rights reserved.

Holt Science and Technology

5

Body Organization and Structure

Back

Print

Name Class Date

Directed Reading A continued

12. When your arm straightens, the

muscle is

the extensor. USE IT OR LOSE IT

13. How does having strong muscles benefit the rest of the body?

14. Skeletal muscles can be strengthened by doing 15. When you do resistance exercise, you work against the resistance, or

.

, of an object.

16. What are some examples of aerobic exercise?

17. Endurance can be increased by doing

.

MUSCLE INJURY ______18. Why should you start an exercise program slowly? a. You are less likely to get hurt. c. You save time. b. You enjoy it more. d. You increase resistance. ______19. A strain is an injury in which a muscle or tendon is a. fractured or broken. c. swollen or inflamed. b. overstretched or torn. d. dislocated or moved. ______20. Tendinitis is a condition in which a tendon becomes a. less dense. c. rested. b. bruised. d. inflamed.

21. What are the dangers of taking anabolic steroids?

Copyright © by Holt, Rinehart and Winston. All rights reserved.

Holt Science and Technology

6

Body Organization and Structure

Back

Print

Name Class Date

Skills Worksheet

Directed Reading A

Section: The Integumentary System

______ 1. What is the largest organ in the body? a. the heart b. the lungs c. the skin d. the stomach

2. The integumentary system is made up of

, .

, and FUNCTIONS OF SKIN

3. Skin protects you by keeping

in your body and

out of your body.

4. You can feel things around you through the

in

your skin.

5. Small organs in the skin called

make sweat and

help to regulate body temperature.

6. Skin helps get rid of 7. Darker skin has more

through sweating. than lighter skin.

8. How does the melanin in skin help prevent cancer?

Copyright © by Holt, Rinehart and Winston. All rights reserved.

Holt Science and Technology

7

Body Organization and Structure

Back

Print

Name Class Date

Directed Reading A continued

LAYERS OF SKIN ______ 9. How does the dermis differ from the epidermis? a. It is thinner. c. It is made of keratin. b. It is made of dead cells. d. It is thicker.

Match the correct description with the correct term. Write the letter in the space provided.

______10. keep hair flexible and waterproofs the dermis ______11. make hair ______12. can contract and cause hair to stand up ______13. help regulate body temperature and transport substances ______14. carry messages to and from the brain ______15. cool the body and remove waste

16. The outermost layer of the skin is the

a. blood vessels b. nerve fibers c. hair follicles d. muscle fibers e. oil glands f. sweat glands

.

17. The thicker layer of skin beneath the outermost layer of skin is

the

18. The epidermis is made of

. tissue.

19. Most cells in the epidermis are filled with a protein

called

.

20. The fibers of the dermis are made of a protein

called HAIR AND NAILS

.

______21. Hair and nails are made up of a. skin. b. all dead cells.

c. all living cells. d. living and dead cells.

______22. Which of the following statements is true about a hair follicle? a. It contains living cells. c. It contains all dead cells. b. It makes new skin. d. It contains keratin.

23. Hair gets its color from

.

Copyright © by Holt, Rinehart and Winston. All rights reserved.

Holt Science and Technology

8

Body Organization and Structure

Back

Print

Name Class Date

Directed Reading A continued

24. How does hair protect your body?

25. The living cells that cause a nail to grow are found in the

at the base of the nail. SKIN INJURIES

26. What are some ways in which the skin can become damaged?

27. How does skin heal from a cut?

Copyright © by Holt, Rinehart and Winston. All rights reserved.

Holt Science and Technology

9

Body Organization and Structure

Back

Print

Name Class Date

Skills Worksheet

Directed Reading A

Section: The Cardiovascular System

1. The heart, blood, arteries, veins, capillaries, and lymphatic system make

up the YOUR CARDIOVASCULAR SYSTEM

.

2. The heart and three types of blood vessels together make up

the

3. The word cardio means 4. The word vascular means

. . . that carry blood

5. Arteries, veins, and capillaries are

throughout the body. THE HEART ______ 6. What kind of tissue makes up most of the heart? a. vascular c. circulatory b. cardiac d. lymphatic ______ 7. Each upper chamber of the heart is called a(n) a. atrium. c. valve. b. ventricle. d. cardio. ______ 8. Each lower chamber of the heart is called a(n) a. atrium. c. valve. b. ventricle. d. cardio. ______ 9. The right side of the heart pumps oxygen-poor blood to the a. body. c. right ventricle. b. lungs. d. left atrium. ______10. The left side of the heart pumps oxygen-rich blood to the a. body. c. right ventricle. b. lungs. d. left atrium. ______11. When atria relax, what do ventricles do? a. expand b. relax c. contract d. close

Copyright © by Holt, Rinehart and Winston. All rights reserved.

Holt Science and Technology

1

Circulation and Respiration

Back

Print

Name Class Date

Directed Reading A continued

12. Why do the heart's valves close?

13. What part of the heart makes the "heartbeat" sound?

BLOOD VESSELS

Match the correct definition with the correct term. Write the letter in the space provided.

14. carries blood back to the heart 15. allows exchanges between blood and body cells 16. carries blood away from the heart 17. is pressure caused by heartbeats 18. is caused by a rhythmic change in blood pressure 19. What is the narrowest kind of blood vessel?

a. artery b. blood pressure c. pulse d. capillary e. vein

20. What kind of blood vessels are helped by the contracting of skeletal muscles?

21. What kind of blood vessels stretch due to blood pressure?

TWO TYPES OF CIRCULATION ______22. What is added to blood when it is pumped to the lungs? a. blood vessels b. capillaries c. oxygen d. carbon dioxide ______23. What is taken from blood when it is pumped to the lungs? a. blood vessels b. capillaries c. oxygen d. carbon dioxide

Copyright © by Holt, Rinehart and Winston. All rights reserved.

Holt Science and Technology

2

Circulation and Respiration

Back

Print

Name Class Date

Directed Reading A continued

______24. Where does the exchange of blood and oxygen take place in the lungs? a. cells b. arteries c. capillaries d. veins

25. The flow of blood between the heart to the lungs is

circulation.

26. The flow of blood between the heart and the rest of the body

is CARDIOVASCULAR PROBLEMS

circulation.

27. Cardiovascular problems can harm the whole 28. A healthy diet and plenty of

. can reduce the risk

of cardiovascular problems.

29. What are the leading causes of death in the United States?

Match the correct description with the correct term. Write the letter in the space provided. Some terms will not be used.

______30. fatty buildup in blood vessels

______31. abnormally high blood pressure ______32. brain damage caused by damage to blood vessels ______33. condition caused by the death of heart muscle cells

a. blood poisoning b. heart failure c. heart attack d. atherosclerosis e. stroke f. hypertension

34. What can happen when blood supply to the heart is blocked?

Copyright © by Holt, Rinehart and Winston. All rights reserved.

Holt Science and Technology

3

Circulation and Respiration

Back

Print

Name Class Date

Skills Worksheet

Directed Reading A

Section: Blood

1. An adult body has about

liters of blood.

WHAT IS BLOOD?

2. List the four components of blood.

3. The fluid part of blood is called 4. What do red blood cells do?

.

5. To what does hemoglobin cling?

6. When bleeding starts,

form a plug to reduce

blood loss.

7. What two things do white blood cells do?

8. Pathogens include bacteria,

, and other

microscopic organisms.

9. To fight pathogens, white blood cells destroy pathogens or

release

.

10. What destroys dead or damaged body cells?

Copyright © by Holt, Rinehart and Winston. All rights reserved.

Holt Science and Technology

4

Circulation and Respiration

Back

Print

Name Class Date

Directed Reading A continued

BODY TEMPERATURE REGULATION

11. Blood helps to regulate body 12. When body temperature rises, blood vessels in the skin

.

. BLOOD PRESSURE ______13. The force that blood exerts on the walls of the arteries is called a. systolic pressure. b. blood pressure. c. contraction. d. diastolic pressure.

14. When is systolic pressure measured?

15. When is diastolic pressure measured?

16. What are two organs that can be damaged by high blood pressure?

BLOOD TYPES ______ 17. To what does a blood type refer? a. blood pressure levels b. antibodies c. blood color and consistency d. chemicals called antigens on red blood cells ______18. What kind of antibodies does a person with type A blood have? a. type A b. type B c. type O d. type A and type B

Copyright © by Holt, Rinehart and Winston. All rights reserved.

Holt Science and Technology

5

Circulation and Respiration

Back

Print

Name Class Date

Directed Reading A continued

19. How do type B antibodies react to type B antigens?

BLOOD TYPES AND TRANSFUSIONS ______20. Which blood type is a universal donor? a. A c. AB b. B d. O

21. What does a transfusion attempt to replace?

Copyright © by Holt, Rinehart and Winston. All rights reserved.

Holt Science and Technology

6

Circulation and Respiration

Back

Print

Name Class Date

Skills Worksheet

Directed Reading A

Section: The Lymphatic System

______ 1. A group of organs whose main function is to collect extra fluid from cells and return it to the blood is the a. cardiovascular system. c. circulatory system. b. lymphatic system. d. atria and ventricles.

2. The lymphatic system helps your body to fight

.

VESSELS OF THE LYMPHATIC SYSTEM

3. The smallest lymph vessels are called 4. Why are some particles NOT absorbed by blood vessels?

.

5. Fluid and particles collected by lymphatic vessels and nodes are

called

6. Where does lymph drain?

.

OTHER PARTS OF THE LYMPHATIC SYSTEM ______ 7. Where are most red and white blood cells produced? a. bone marrow b. lymph vessels c. blood vessels d. lymph nodes ______ 8. Special white blood cells that fight pathogens are called a. RBCs. b. nodes. c. lymphocytes. d. bean cells. ______ 9. Small oval masses of lymphatic tissue found in lymphatic vessels are called a. lymph nodes. c. lymph fluids. b. lymph capillaries. d. killer cells.

Copyright © by Holt, Rinehart and Winston. All rights reserved.

Holt Science and Technology

7

Circulation and Respiration

Back

Print

Name Class Date

Directed Reading A continued

______10. What do lymph nodes do? a. remove nodes b. create new lymph c. create new blood cells d. remove pathogens and dead cells from lymph ______11. What do killer T cells do? a. produce antibodies b. destroy pathogens c. destroy lymphocytes d. produce antigens ______12. What do B cells do? a. produce antibodies b. destroy pathogens c. destroy lymphocytes d. produce antigens ______13. The main gland of the lymphatic system is the a. bone marrow. b. lymph. c. thymus. d. lymph node.

14. The thymus gland produces

that are ready to

fight infection.

15. The largest organ in the lymphatic system is the 16. List the two important functions of the spleen.

.

17. List four things the spleen does with red blood cells.

18. The lymphatic tissues at the back of the mouth are called

.

19. Tonsils help defend the body against

.

Copyright © by Holt, Rinehart and Winston. All rights reserved.

Holt Science and Technology

8

Circulation and Respiration

Back

Print

Name Class Date

Skills Worksheet

Directed Reading A

Section: The Respiratory System

1. Your body needs oxygen in order to get

from the

food you eat. RESPIRATION AND THE RESPIRATORY SYSTEM

Match the correct description with the correct term. Write the letter in the space provided.

______ 2. process of using oxygen and releasing carbon dioxide and water ______ 3. inhalation and exhalation ______ 4. area of the throat that contains the vocal chords ______ 5. group of organs that take in oxygen and get rid of carbon dioxide ______ 6. main passage into and out of the respiratory system

a. breathing b. larynx c. nose d. pharynx e. respiration f. respiratory system g. alveoli h. bronchioles i. bronchus j. cellular respiration k. trachea

______ 7. throat

______ 8. use of oxygen by cells to release energy stored in food ______ 9. tube guarded by the larynx ______10. tube that connects the trachea to the lungs ______11. smaller branches of bronchi

______12. tiny sacs at the ends of the bronchioles

Copyright © by Holt, Rinehart and Winston. All rights reserved.

Holt Science and Technology

9

Circulation and Respiration

Back

Print

Name Class Date

Directed Reading A continued

BREATHING

13. List the two kinds of muscle involved with breathing.

14. When you inhale, the 15. When the diaphragm contracts, the

contracts. contract and

lift the rib cage. BREATHING AND CELLULAR RESPIRATION

16. When you breathe, you take in 17. Oxygen diffuses into

. .

18. When the oxygen is carried to cells, it is used to release

.

19. Cellular respiration produces water and

.

RESPIRATORY DISORDERS ______20. What may trigger asthma? a. blood cells b. dust or pollen c. antigens d. SARS ______21. What causes SARS? a. dust or pollen b. a virus c. bacteria d. asthma

Copyright © by Holt, Rinehart and Winston. All rights reserved.

Holt Science and Technology

10

Circulation and Respiration

Back

Print

Name Class Date

Skills Worksheet

Directed Reading A

Section: The Digestive System

______ 1. What is the digestive system? a. the liver, pancreas, and small intestine b. a group of organs that work together to break down food c. the large intestine, gallbladder, and esophagus d. a group of veins and arteries that work together to digest food DIGESTIVE SYSTEM AT A GLANCE ______ 2. Which of the following organs is NOT part of the digestive tract? a. stomach b. pharynx c. large intestine d. kidneys

3. Food passes through some of the organs of the digestive system but not others. Which organs does food NOT pass through?

BREAKING DOWN FOOD ______ 4. What are the two main kinds of digestion? a. mechanical and chemical b. mechanical and liquid c. mechanical and solid d. mechanical and heat

5. The kind of digestion that takes place when you chew your

food is

.

6. When your body breaks down food into nutrients,

digestion takes place.

7. The major types of nutrients are

, fats,

and proteins.

8. What substances cut up the protein chains?

9. Proteins are made up of chains of smaller molecules

called

.

Copyright © by Holt, Rinehart and Winston. All rights reserved.

Holt Science and Technology

1

The Digestive and Urinary Systems

Back

Print

Name Class Date

Directed Reading A continued

DIGESTION BEGINS IN THE MOUTH

10. Why is chewing important?

For each kind of tooth listed, write whether it shreds, grinds, or mashes food.

11. premolars 12. incisors 13. canines 14. molars 15. As you chew your food, it is mixed with 16. Saliva changes complex carbohydrates into

. ,

which are easier to digest.

17. How does the food get from your mouth to your throat?

18. What is the function of the esophagus?

THE HARSH ENVIRONMENT OF THE STOMACH

19. What does the stomach do?

20. What do glands in the stomach produce?

21. What happens to most of the bacteria that you swallow with your food?

22. When the food moves out of the stomach, it is a soupy mixture

called

.

Copyright © by Holt, Rinehart and Winston. All rights reserved.

Holt Science and Technology

2

The Digestive and Urinary Systems

Back

Print

Name Class Date

Directed Reading A continued

23. Where does the chyme go when it leaves the stomach?

THE PANCREAS AND SMALL INTESTINE

24. What organ makes fluid that protects the small intestine from the acid in the chyme?

25. The pancreas produces 26. Why is the small intestine called "small"?

to regulate blood sugar.

27. What do the villi in the small intestine do?

THE LIVER AND GALLBLADDER ______28. Which of the following is NOT a job of the liver? a. It stores bile. b. It stores nutrients. c. It breaks down toxins. d. It breaks up fat.

29. What is the job of the gallbladder?

30. What does bile do?

31. Which organ breaks down chemicals in the body such as alcohol and drugs?

Copyright © by Holt, Rinehart and Winston. All rights reserved.

Holt Science and Technology

3

The Digestive and Urinary Systems

Back

Print

Name Class Date

Directed Reading A continued

THE END OF THE LINE ______32. Which of the following is NOT a job of the large intestine? a. absorbing water b. producing fiber c. producing feces d. storing excess material

33. What is fiber?

34. How does solid waste, or feces, leave the body?

Copyright © by Holt, Rinehart and Winston. All rights reserved.

Holt Science and Technology

4

The Digestive and Urinary Systems

Back

Print

Name Class Date

Skills Worksheet

Directed Reading A

Section: The Urinary System

______ 1. What is excretion? a. the process of digesting food b. the process of breathing c. the process of removing waste from the body d. the process of adding nutrients to the body

2. What is the job of the urinary system?

CLEANING THE BLOOD

3. What are two examples of wastes that the urinary system removes from the blood?

THE KIDNEYS AS FILTERS ______ 4. How many kidneys does a person normally have? a. one b. two c. three d. four ______ 5. Which of the following is the job of the nephrons? a. They remove wastes from the blood. b. They produce urea. c. They produce urine. d. They clean the kidneys.

6. What do the kidneys do?

7. What is urea?

Copyright © by Holt, Rinehart and Winston. All rights reserved.

Holt Science and Technology

5

The Digestive and Urinary Systems

Back

Print

Name Class Date

Directed Reading A continued

WATER IN, WATER OUT ______ 8. Why do humans sweat? a. to cleanse the skin b. to cool the body c. to produce saliva d. to control thirst

9. Why does your body need to excrete as much water as it brings in?

10. What does ADH do?

11. What effect does a diuretic have on your body?

URINARY SYSTEM PROBLEMS ______12. Kidney stones are made of which of the following substances? a. viruses b. waste materials c. ADH d. bacteria

13. How can bacteria get into the bladder and ureters?

14. What can happen if the nephrons are damaged?

Copyright © by Holt, Rinehart and Winston. All rights reserved.

Holt Science and Technology

6

The Digestive and Urinary Systems

Back

Print

Name Class Date

Skills Worksheet

Directed Reading A

Section: The Nervous System

TWO SYSTEMS WITHIN A SYSTEM

1. What is the central nervous system?

2. What is the peripheral nervous system?

Mark each of the following statements P for peripheral nervous system or C for central nervous system.

______ 3. includes nerves ______ 4. acts as the control center for your body ______ 5. includes your brain and spinal cord ______ 6. connects all areas of your body to the brain and spinal cord

THE PERIPHERAL NERVOUS SYSTEM

7. Nerve cells specialized to receive and conduct electrical impulses are

called

8. Electrical messages, called

. , may travel as fast as

150 m/s or as slow as 0.2 m/s.

Match the correct description with the correct term. Write the letter in the space provided.

______ 9. allows the neuron to receive information ______10. a long fiber that transmits information to other cells ______11. contains cell organelles and a nucleus 12. The tip of each branch of an axon is called a(n)

a. cell body b. dendrite c. axon

.

Copyright © by Holt, Rinehart and Winston. All rights reserved.

Holt Science and Technology

1

Communication and Control

Back

Print

Name Class Date

Directed Reading A continued

13. Specialized nerve endings on sensory neurons that detect changes inside and

outside the body are called

.

14. Neurons that send impulses from the brain and spinal cord to other systems

are called NERVES

______15. Nerves do NOT contain a. muscle fiber. b. blood vessels. c. axons. d. connective tissue.

.

16. Nerves may contain the axons of both

and

neurons. SOMATIC AND AUTONOMIC NERVOUS SYSTEMS ______ 17. The two parts of the peripheral nervous system are a. neurons and cell bodies. b. nerve cells and brain cells. c. CNS and PNS. d. sensory neurons and motor neurons.

18. The

part of the peripheral nervous system is

composed of the somatic and autonomic nervous systems.

Mark each of the following statements S for somatic nervous system or A for autonomic nervous system.

______19. is under your conscious control ______20. controls digestion and heart rate ______21. is composed of sympathetic and parasympathetic nervous systems ______22. is used for writing, talking, and other voluntary movements ______23. maintains a stable internal environment (homeostasis) THE CENTRAL NERVOUS SYSTEM

24. What is the largest organ of the central nervous system?

Copyright © by Holt, Rinehart and Winston. All rights reserved.

Holt Science and Technology

2

Communication and Control

Back

Print

Name Class Date

Directed Reading A continued

Mark each of the following actions V for voluntary or I for involuntary.

______25. digestion

______26. moving your arm ______ 27. body processes that happen automatically 28. The three connected parts of the brain are the

, the . . hemisphere of

, and the

29. Most memories are stored in the 30. The right hand is controlled by the

the cerebrum.

31. Which part of the brain keeps track of your body's position?

32. Your body's involuntary processes, such as heart rate, are controlled

by the THE SPINAL CORD

33. The spinal cord is protected by 34. The spinal cord is made of

.

. and

.

35. Nerve fibers in your spinal cord allow your brain to communicate

with your

nervous system.

36. A spinal cord injury may block all information to and from

the

.

37. What is the possible effect of a spinal cord injury?

38. What are two ways to help prevent spinal cord injuries?

Copyright © by Holt, Rinehart and Winston. All rights reserved.

Holt Science and Technology

3

Communication and Control

Back

Print

Name Class Date

Skills Worksheet

Directed Reading A

Section: Responding to the Environment

1. How do you know when someone is tapping on your shoulder if you don't see them?

SENSE OF TOUCH

______ 2. Which of these is NOT sensed by skin receptors? a. vibration b. pressure c. pain d. light 3. A thermoreceptor responds to changes in 4. The purpose of the integumentary system is to

. .

RESPONDING TO SENSORY MESSAGES

5. An involuntary and almost immediate response to a stimulus is

called a(n)

.

6. A series of events in which one step controls or affects a previous

step is a(n)

.

7. How frequently does the brain process information from skin receptors?

SENSE OF SIGHT

______ 8. Why does a carrot look orange to you? a. My rods see only orange light. b. The carrot deflects blue light. c. The carrot reflects orange light. d. None of the above

Copyright © by Holt, Rinehart and Winston. All rights reserved.

Holt Science and Technology

4

Communication and Control

Back

Print

Name Class Date

Directed Reading A continued

Match the correct description with the correct term. Write the letter in the space provided.

______ 9. photoreceptor needed to see color ______10. opening in the eye ______11. carries nerve impulses from photoreceptors ______12. protects the eye and allows light to enter ______13. neuron that changes light into electrical impulses ______14. photoreceptor important for night vision ______15. light-sensitive layer in the back of the eye

a. cornea b. pupil c. retina d. optic nerve e. rod f. cone g. photoreceptor

16. The part of the eye that gives it color and controls the light passing to the

retina is the

.

17. How does the shape of the lens change in order to focus on an object?

18. Which type of vision problem occurs when the lens of the eye focuses light in front of the retina instead of on the retina?

19. If you want to correct farsightedness, should you choose a lens that is convex or concave?

SENSE OF HEARING

20. When vibrations push on air particles, which push on other air particles,

they create

energy.

Copyright © by Holt, Rinehart and Winston. All rights reserved.

Holt Science and Technology

5

Communication and Control

Back

Print

Name Class Date

Directed Reading A continued

Put the following statements in the proper sequence from 1 to 5 to explain how we hear. Write the appropriate number in the space provided.

______21. One of the tiny ear bones vibrates against a fluid-filled organ. ______22. Inside the cochlea, vibrations create waves. ______23. Sound waves are funneled to the ear canal. ______24. Neurons convert waves into electrical impulses and send them to the brain. ______25. The eardrum vibrates against tiny bones.

26. A coiled tube found in the inner ear is the

.

SENSE OF TASTE

Match the correct description with the correct term. Write the letter in the space provided.

______ 27. tiny bumps that cover the tongue ______28. contained inside papillae ______29. receptors for taste

30. Taste cells respond to saltiness, sweetness, sourness,

a. taste cells b. papillae c. taste buds

and SENSE OF SMELL

.

31. Smell receptors located in the upper part of your nasal cavity are

called

.

32. The sensation of flavor happens when the brain combines information from

your taste buds and your

.

Copyright © by Holt, Rinehart and Winston. All rights reserved.

Holt Science and Technology

6

Communication and Control

Back

Print

Name Class Date

Skills Worksheet

Directed Reading A

Section: The Endocrine System

HORMONES AS CHEMICAL MESSENGERS

Match the correct description with the correct term. Write the letter in the space provided.

______ 1. controls body function using chemicals made by endocrine glands ______ 2. group of cells that make special chemicals for the body ______ 3. substance made in one cell or tissue that causes a change in another cell or tissue

a. gland b. endocrine system c. hormone

4. What chemical messenger produces the "fight or flight" response?

MORE ENDOCRINE GLANDS

5. The sum of all the chemical processes that take place in an organism

is

6. The thymus gland produces

. , which help destroy

cells that invade your body.

Match the correct description with the correct term. Write the letter in the space provided.

______ 7. helps your body fight disease ______ 8. increases the rate at which you use energy ______ 9. regulates blood-sugar levels ______10. produce hormones involved in reproduction in males ______11. produce hormones involved in reproduction in females ______12. helps the body respond to danger ______13. regulates calcium levels ______14. secretes hormones that affect other glands and organs

Copyright © by Holt, Rinehart and Winston. All rights reserved.

a. thyroid b. adrenal c. testes d. pituitary e. ovaries f. pancreas g. parathyroid h. thymus

Holt Science and Technology

7

Communication and Control

Back

Print

Name Class Date

Directed Reading A continued

CONTROLLING THE ENDOCRINE GLANDS

15. How are endocrine glands controlled?

16. Insulin is the hormone in the

mechanism that

controls the level of glucose in the blood.

Place the following statements in the correct order from 1 to 5 to explain the feedback control that regulates blood sugar. Write the appropriate number in the space provided.

______ 17. Glucose is absorbed into the bloodstream by the small intestine. ______18. Blood-glucose level returns to normal, pancreas stops releasing insulin. ______19. The pancreas releases insulin into the blood. ______20. As blood sugar falls below normal, the liver breaks down stored glycogen and releases glucose into the blood. ______21. Insulin signals the liver to take in glucose, which is converted to glycogen and stored for future use. HORMONE IMBALANCES

22. What condition is caused when the body does not make enough insulin?

23. How can a person with diabetes keep the glucose in the blood at a safe level?

24. What happens if a child's pituitary gland doesn't make enough growth hormone?

25. A lack of growth hormone is likely to be treated by a prescription

of

.

Copyright © by Holt, Rinehart and Winston. All rights reserved.

Holt Science and Technology

8

Communication and Control

Back

Print

Name Class Date

Skills Worksheet

Directed Reading A

Section: Animal Reproduction

1. Why is it necessary for living things to reproduce?

ASEXUAL REPRODUCTION

2. When an offspring has one parent, it is called

reproduction.

3. An offspring produced by asexual reproduction is

identical to its parent.

4. When a part of a parent organism pinches off and forms a new organism, it is

called

. , parts of it break

5. When an organism reproduces by

off and develop into an identical individual.

6. A sea star reproduces by

.

SEXUAL REPRODUCTION ______ 7. In sexual reproduction, two parents contribute part of the offspring's a. genes. c. eggs. b. nucleus. d. parents. ______ 8. What is a female's sex cell called? a. zygote c. gene b. egg d. sperm ______ 9. What is a male's sex cell called? a. penis b. DNA

c. sperm d. zygote

______10. The union of a male sex cell with a female's sex cell is called a. meiosis. c. fertilization. b. generations. d. chromosomes. ______11. All human cells, except sex cells and mature red blood cells, contain how many chromosomes? a. 46 c. 23 b. 2 d. 12

Copyright © by Holt, Rinehart and Winston. All rights reserved.

Holt Science and Technology

1

Reproduction and Development

Back

Print

Name Class Date

Directed Reading A continued

______12. The number of chromosomes in sex cells is produced by a cell division process called a. combination. c. meiosis. b. fertilization. d. a zygote. INTERNAL AND EXTERNAL FERTILIZATION ______13. What occurs during external fertilization? a. The sperm fertilizes eggs outside the female's body. b. The female must find water. c. The male puts sperm inside the female. d. The female produces both eggs and sperm. ______14. Which of the following is an advantage of internal fertilization? a. More offspring are produced. b. It's easier to find a mate. c. The males produce fewer sperm. d. The fertilized eggs are protected. ______15. Many mammals that use internal fertilization give birth to live young that develop a. inside an egg. c. inside a pouch. b. inside the female's body. d. in a moist environment. MAMMALS ______16. All mammals reproduce sexually and feed their young on a. milk. c. eggs. b. seeds. d. blood.

Match the correct description with the correct term. Write the letter in the space provided.

______ 17. The female nourishes young inside her body before birth. ______18. The partially developed young continue to develop inside the mother's pouch. ______19. The female lays eggs that hatch, then nourishes them with milk.

a. monotreme b. placental mammal c. marsupial

Copyright © by Holt, Rinehart and Winston. All rights reserved.

Holt Science and Technology

2

Reproduction and Development

Back

Print

Name Class Date

Directed Reading A continued

For each type of mammal listed, write whether it is a marsupial, a placental mammal, or a monotreme.

20. 21. 22. 23. 24. 25.

human platypus opposum echidna kangaroo bat

Copyright © by Holt, Rinehart and Winston. All rights reserved.

Holt Science and Technology

3

Reproduction and Development

Back

Print

Name Class Date

Skills Worksheet

Directed Reading A

Section: Human Reproduction

THE MALE REPRODUCTIVE SYSTEM

Match the correct definition with the correct term. Write the letter in the space provided.

______ 1. place where male's sperm is produced ______ 2. male hormone that regulates the development of sperm ______ 3. mixture of sperm and other fluids ______ 4. place where sperm mixes with fluid ______ 5. tube that stores sperm ______ 6. tube through which semen is carried out of the penis ______ 7. male's exterior sex organ THE FEMALE REPRODUCTIVE SYSTEM

a. testes b. urethra c. epididymis d. semen e. vas deferens f. testosterone g. penis

______ 8. A female's eggs and her sex hormones are produced in her a. zygote. c. fallopian tubes. b. estrogen. d. ovaries. ______ 9. An egg travels into a fallopian tube during a. menstruation. c. fertilization. b. ovulation. d. pregnancy. ______10. Fallopian tubes connect the ovaries with the a. uterus. c. vagina. b. zygote. d. eggs. ______11. A zygote develops in the female's a. ovary. b. vagina.

c. uterus. d. placenta.

______12. The canal between the outside of the body and the uterus is the a. zygote. c. vagina. b. placenta. d. fallopian tubes.

Copyright © by Holt, Rinehart and Winston. All rights reserved.

Holt Science and Technology

4

Reproduction and Development

Back

Print

Name Class Date

Directed Reading A continued

13. When does a woman begin menstruating? When does menstruation stop?

14. On the first day of the menstrual cycle, what does the uterus discharge?

15. What occurs on about the 14th day of the menstrual cycle?

16. About how long does a complete menstrual cycle last?

MULTIPLE BIRTHS

17. Children who are born at the same time and who share the exact same genes

are called

. .

18. Of all twin births, identical twins make up about

19. Children who are born at the same time but who can look very different from

each other are called

.

20. A rare type of multiple birth occurring when a mother gives birth to five

babies is called REPRODUCTIVE SYSTEM PROBLEMS

.

______21. Which one of the following is a sexually transmitted disease (STD)? a. influenza c. herpes b. tuberculosis d. smallpox ______22. How can an infected person can pass on an STD to another person? a. through sneezing b. through casual contact c. by shaking hands d. through sexual contact ______23. Hepatitis B is an STD that mainly affects which organ? a. the penis c. the liver b. the heart d. the uterus ______24. AIDS is an STD that is caused by a. herpes. b. a virus.

c. the immune system. d. poor hygiene.

Copyright © by Holt, Rinehart and Winston. All rights reserved.

Holt Science and Technology

5

Reproduction and Development

Back

Print

Name Class Date

Directed Reading A continued

______25. Which one of the following is a common reproductive system cancer among men? a. cancer of the prostate b. cancer of the liver c. cancer of the vas deferens d. cancer of the blood ______26. Which one of the following is a common reproductive system cancer among women? a. cancer of the vagina b. cancer of the breast c. cancer of the neck d. cancer of the fallopian tubes ______ 27. The most common cause of male infertility is a. cancer. b. blockage of the epididymis. c. the lack of healthy sperm. d. a virus. ______28. The most common cause of female infertility is a. abnormal ovulation. c. hepatitis B. b. cancer. d. a recent pregnancy.

Copyright © by Holt, Rinehart and Winston. All rights reserved.

Holt Science and Technology

6

Reproduction and Development

Back

Print

Name Class Date

Skills Worksheet

Directed Reading A

Section: Growth and Development

FROM FERTILIZATION TO EMBRYO ______ 1. Ordinarily, how many sperm fertilize a female's egg? a. several million c. one b. a few hundred d. six to ten ______ 2. An egg is fertilized after the union of the egg's and sperm's a. membranes. c. semen. b. nucleus. d. zygote. ______ 3. About 5 days after fertilization, the egg arrives at the a. fallopian tubes. c. cervix. b. vagina. d. uterus. ______ 4. Which one of the following is a characteristic of an embryo? a. It is a tiny ball of cells. c. It develops in the vagina. b. It is not yet fertilized. d. It is less than 1 day old. FROM EMBRYO TO FETUS ______ 5. Which of the following is a characteristic of the placenta? a. It's an exchange organ between mother and embryo. b. It contains very few blood vessels. c. It becomes an organ in the developing embryo. d. It contracts to help the mother give birth. ______ 6. The child developing inside the mother's uterus is connected to the placenta by a tube called a. the vagina. c. the amnion. b. an embryo. d. the umbilical cord. ______ 7. A developing embryo is called a. an amnion. b. a fetus.

c. a zygote. d. a placenta.

Copyright © by Holt, Rinehart and Winston. All rights reserved.

Holt Science and Technology

7

Reproduction and Development

Back

Print

Name Class Date

Directed Reading A continued

Match the correct description with the correct term. Write the letter in the space provided.

______ 8. the heartbeat begins ______ 9. the spinal cord and regions of the brain begin to develop ______10. the fetus's eyes can perceive light ______11. the fetus doubles in size and begins to move ______12. the fetus is able to hear sounds BIRTH

a. weeks 1­4 b. weeks 5­8 c. weeks 9­16 d. weeks 17­24 e. weeks 25­36

______13. The mother's muscle contractions that help a baby to be born are called a. the uterus. c. labor. b. the placenta. d. full-term. ______14. Your navel is the place on your body that was once attached to a. the uterus. c. a fallopian tube. b. the amnion. d. the umbilical cord. FROM BIRTH TO DEATH ______15. Which of the following is a characteristic of infancy? a. baby teeth appear c. begin to read b. begin to run d. need little sleep ______16. Which of the following is a characteristic of childhood? a. grow relatively slowly c. produce sex hormones b. lose flexibility d. have well-coordinated muscles

17. You become an adolescent after you have reached 18. What are two ways in which a male's body changes after puberty?

.

19. What are two ways in which a female's body changes after puberty?

20. What are two early signs of aging in adults under the age of 40?

21. What are two signs of aging in adults over the age of 65?

Copyright © by Holt, Rinehart and Winston. All rights reserved.

Holt Science and Technology

8

Reproduction and Development

Back

Print

Name Class Date

Skills Worksheet

Directed Reading A

Section: Disease

CAUSES OF DISEASE

1. When you have a(n)

, your normal body processes

are disrupted.

2. Diseases that are not spread from one person to another are

called

diseases.

Match the correct definition with the correct term. Write the letter in the space provided.

______ 3. a type of noninfectious disease ______ 4. a disease that is caused by a pathogen ______ 5. a type of infectious disease ______ 6. a disease that is not spread from one person to another ______ 7. an agent that causes infectious disease

a. noninfectious disease b. cancer c. pathogen d. infectious disease e. strep throat

8. When a disease can be passed from one person to another, it is

a(n)

disease.

9. Viruses and some bacteria, fungi, protists, and worms may all be disease-

causing agents called PATHWAYS TO PATHOGENS

.

______10. Which is NOT a way that pathogens are passed to someone? a. through contact with contaminated objects b. through other persons or animals c. through the air or water d. through genetic defects

Copyright © by Holt, Rinehart and Winston. All rights reserved.

Holt Science and Technology

1

Body Defenses and Disease

Back

Print

Name Class Date

Directed Reading A continued

Match the correct description with the correct term. Write the letter in the space provided.

______11. one way that pathogens move through the air ______12. something a sick person might contaminate ______13. a disease people might catch from dogs ______14. a disease often spread by ticks ______15. one way that people touch and spread disease

16. When water lines break,

a. Lyme disease b. ringworm c. shaking hands d. a doorknob e. sneezing

can enter the public

water supply.

17. People sometimes get sick because of

that grow

in food.

18. Meat, fish, or eggs can be dangerous if they are not

enough.

19. Leaving food out at room temperature allows bacteria such

as

to grow.

20. The growth of pathogens is slowed when food is put in

a(n)

. also helps to

21. Keeping counters and cooking tools

make eating safer. PUTTING PATHOGENS IN THEIR PLACE ______22. Until the twentieth century, surgery patients often died of a. Lyme disease. c. bacterial infections. b. Rocky Mountain fever. d. AIDS. ______23. Among the things modern-day hospitals use to stop infections are a. ice and heating pads. c. cold water and towels. b. boiling water and chemicals. d. viruses and worms. ______24. What did Louis Pasteur find in wine? a. bacteria c. ticks b. viruses d. chemicals

Copyright © by Holt, Rinehart and Winston. All rights reserved.

Holt Science and Technology

2

Body Defenses and Disease

Back

Print

Name Class Date

Directed Reading A continued

______25. What did Pasteur use to kill most of the bacteria? a. ice c. heat b. chemicals d. medicine ______26. The process of using heat to kill bacteria is called a. pasteurization. c. immunization. b. vaccination d. depathogenization.

27. What did Edward Jenner find out about people who had been infected with cowpox?

28. The ability to resist or recover from an infectious disease is known

as

. .

29. Jenner's work led to the first modern

30. What do modern vaccines contain to help your body develop defenses against disease?

31. Doctors can usually treat bacterial infections with _______________________. 32. List the two things that antibiotics can do to bacteria.

33. Why can't antibiotics kill viruses?

34. How can viruses be destroyed?

Copyright © by Holt, Rinehart and Winston. All rights reserved.

Holt Science and Technology

3

Body Defenses and Disease

Back

Print

Name Class Date

Skills Worksheet

Directed Reading A

Section: Your Body's Defenses

1. Your body has to constantly protect itself against

that are trying to invade it. FIRST LINES OF DEFENSE ______ 2. Which of these is NOT a first line of defense for your body? a. enzymes c. dead skin b. mucus d. antibiotics ______ 3. Most pathogens that are carried to the stomach a. have gotten through the defenses. b. cause hunger. c. are digested. d. may get into the blood. ______ 4. What two lines of defense does human skin have? a. dead skin flakes and oil glands b. living skin and mucus c. oil and water d. enzymes and mucus FAILURE OF FIRST LINES

5. Pathogens can enter the body when skin is

or punctured.

6. Cell parts called

help to seal an open wound. .

7. The body system that fights pathogens is the 8. The purpose of the immune system is to protect the body from

invading CELLS OF THE IMMUNE SYSTEM

.

9. Name the three main kinds of cells that make up the immune system.

Copyright © by Holt, Rinehart and Winston. All rights reserved.

Holt Science and Technology

4

Body Defenses and Disease

Back

Print

Name Class Date

Directed Reading A continued

Match the correct definition with the correct term. Write the letter in the space provided.

______10. engulf and digest many microorganisms or viruses ______11. make antibodies ______12. bind to specific antigens ______13. coordinate the immune system and attack infected cells ______14. stimulate an immune response ______15. recognizes and attacks foreign substances RESPONDING TO A VIRUS

a. antibodies b. B cells c. antigen d. T cells e. macrophages f. immune system

16. When virus particles invade a body, some of the particles are engulfed and

broken up by

.

17. If virus particles survive in the body, they may enter a cell and start

to

.

18. What do macrophages, infected body cells, and virus particles all display?

19. What two responses do helper T cells activate to fight viruses?

20. What do killer T cells destroy?

21. When activated B cells divide, what do they form?

22. Describe how antibodies help to destroy viruses.

Copyright © by Holt, Rinehart and Winston. All rights reserved.

Holt Science and Technology

5

Body Defenses and Disease

Back

Print

Name Class Date

Directed Reading A continued

FEVERS

23. When macrophages tell the brain to "turn up the thermostat," the result is

a(n)

.

24. List two reasons why having a mild fever actually helps you to fight infections.

MEMORY CELLS

25. Why are you much more likely to get sick the first time you are infected with a pathogen?

26. A B cell that responds more strongly to a second infection is known as

a(n)

.

CHALLENGES TO THE IMMUNE SYSTEM

Match the correct description with the correct term. Write the letter in the space provided.

______ 27. an overreaction to a harmless substance ______28. an attack by the immune system on the body's own cells ______29. uncontrolled cell growth leading to invasion of healthy tissues ______30. an example of an infection in the immune system

31. Allergies may be caused by certain foods, medicines,

a. autoimmune disease b. cancer c. allergy d. HIV

and

32. In a(n)

. , immune-system cells mistake body cells

for pathogens.

33. What do cancers do that may lead to death?

Copyright © by Holt, Rinehart and Winston. All rights reserved.

Holt Science and Technology

6

Body Defenses and Disease

Back

Print

Name Class Date

Directed Reading A continued

34. Cells growing at an uncontrolled rate are usually destroyed by

cells.

35. To what condition does HIV infection lead?

36. Explain why the immune system of people with AIDS is compromised.

Copyright © by Holt, Rinehart and Winston. All rights reserved.

Holt Science and Technology

7

Body Defenses and Disease

Back

Print

Name Class Date

Skills Worksheet

Directed Reading A

Section: Good Nutrition

NUTRIENTS ______ 1. To stay healthy, you need to take in six kinds of a. cholesterols. b. fats. c. sugars. d. nutrients.

2. What are the six classes of nutrients?

3. Energy is provided for the body in units called 4. Your body's main source of energy is 5. What are the two kinds of carbohydrates?

. .

6. You get quick energy from 7. For long-lasting energy, you need

. .

8. Carbohydrates are energy-giving nutrients that include sugars,

, and fiber.

Copyright © by Holt, Rinehart and Winston. All rights reserved.

Holt Science and Technology

1

Staying Healthy

Back

Print

Name Class Date

Directed Reading A continued

9. What are three sources of fiber?

10. Nutrients used to build and repair your body are called

.

11. To build proteins, your body needs to obtain building blocks called

from food.

12. Food sources that provide all of the essential amino acids are called

.

13. Food sources that contain only some of the essential amino acids are called

.

14. Energy-storage nutrients are 15. What are the two types of fats?

.

16. What do saturated fats do to blood cholesterol levels?

17. High levels of cholesterol increase the risk for 18. What do unsaturated fats do to blood cholesterol levels?

.

19. What are two sources of unsaturated fats?

20. What nutrient makes up 70% of your body?

21. What are the three main functions of water in the body?

Copyright © by Holt, Rinehart and Winston. All rights reserved.

Holt Science and Technology

2

Staying Healthy

Back

Print

Name Class Date

Directed Reading A continued

22. How many glasses of water a day do some scientists think people should drink?

23. Elements that are essential for certain body processes are

.

24. What are the six minerals that your body needs in large amounts?

25. How many minerals does your body need in lesser amounts?

26. Which mineral regulates heartbeat?

27. Which mineral helps produce red blood cells?

28. A class of nutrients called

are needed in small

amounts to control many body functions.

Match the correct description with the correct term. Write the letter in the space provided.

______29. protects red blood cells ______30. helps the body fight disease ______31. assists with blood clotting ______32. helps keep skin healthy and build strong teeth ______33. helps the body use calcium

a. vitamin A b. vitamin K c. vitamin C d. vitamin D e. vitamin E

Copyright © by Holt, Rinehart and Winston. All rights reserved.

Holt Science and Technology

3

Staying Healthy

Back

Print

Name Class Date

Directed Reading A continued

EATING FOR GOOD HEALTH ______34. How can you use the Food Guide Pyramid? a. to make healthy food choices b. to count Calories c. to explain food labels d. to compare nutrients

Match the correct description with the correct term. Write the letter in the space provided.

______35. 3 to 5 servings recommended on the Food Guide Pyramid ______36. 2 to 4 servings recommended on the Food Guide Pyramid ______ 37. use sparingly according to the Food Guide Pyramid ______38. 6 to 11 servings recommended on the Food Guide Pyramid READING FOOD LABELS

a. fats, oils, and sweets b. vegetables c. fruits d. bread, cereal, rice, and pasta

______39. What kind of food must carry food labels? a. soups only c. packaged foods b. home-grown foods d. fresh fruit

40. What do Nutrition Facts labels tell you about the nutrients in a food?

NUTRITIONAL DISORDERS ______41. What can cause nutritional disorders? a. healthy eating habits b. unhealthy eating habits c. not washing hands d. badly cooked food

Copyright © by Holt, Rinehart and Winston. All rights reserved.

Holt Science and Technology

4

Staying Healthy

Back

Print

Name Class Date

Directed Reading A continued

Match the correct definition with the correct term. Write the letter in the space provided.

______42. not eating enough nutrients ______43. having an extremely high percentage of body fat ______44. binge eating followed by vomiting ______45. an intense fear of gaining weight

a. malnutrition b. anorexia nervosa c. bulimia nervosa d. obesity

46. What are three consequences of anorexia nervosa and bulimia nervosa?

47. What are two actions that can help reduce obesity?

Copyright © by Holt, Rinehart and Winston. All rights reserved.

Holt Science and Technology

5

Staying Healthy

Back

Print

Name Class Date

Skills Worksheet

Directed Reading A

Section: Risks of Alcohol and Other Drugs

WHAT IS A DRUG?

1. A chemical substance that causes a physical or psychological change is called

a(n)

.

Match the correct description with the correct term. Write the letter in the space provided.

______ 2. speed up the central nervous system ______ 3. control cold and allergy symptoms ______ 4. fight bacterial infections ______ 5. slow down the central nervous system

______ 6. relieve pain

a. analgesics b. antibiotics c. antihistamines d. stimulants e. depressants

DEPENDENCE AND ADDICTION

7. The body can develop

to

a drug, which means that larger and larger doses are needed.

8. The body can form a(n)

or need for a drug.

9. If a person has a physical dependence on a drug, and does not get the drug,

he or she may experience

.

10. The loss of control of drug-taking behavior is known as

.

11. Some people feel powerful cravings for a drug, a sign of

. TYPES OF DRUGS

12. Some herbs contain

with important healing

properties.

13. Herbal tea containing

may help sleep.

Copyright © by Holt, Rinehart and Winston. All rights reserved.

Holt Science and Technology

6

Staying Healthy

Back

Print

Name Class Date

Directed Reading A continued

14. Why should herbal drugs be used carefully?

15. Drugs that can be bought without a prescription are called

.

16. A doctor writes a(n)

for some drugs.

17. What are three things that a prescription describes?

18. What are unwanted symptoms caused by a drug called?

19. Where can information on proper drug use be found?

20. List five drug safety tips.

21. Cigarettes contain

, an extremely addictive

substance.

22. Smoking increases your chances for

.

23. How many deaths in the United States each year are related to smoking?

24. Smokeless tobacco can lead to mouth or

cancer.

Copyright © by Holt, Rinehart and Winston. All rights reserved.

Holt Science and Technology

7

Staying Healthy

Back

Print

Name Class Date

Directed Reading A continued

Match the correct description with the correct term. Write the letter in the space provided.

______25. drugs that distort the senses ______26. illegal for people under 21 in most of the United States ______ 27. a disease of physical or mental dependence on alcohol ______28. an illegal drug that causes intense excitement ______29. drugs made from the opium plant ______30. an illegal drug that comes from the Indian hemp plant

a. alcohol b. marijuana c. alcoholism d. cocaine e. narcotics f. hallucinogens

31. What are two ways that alcohol may affect the mind or body?

32. A drug made with a small change to an existing drug is called a(n)

.

33. Sniffing glue or solvents can cause hallucinations or serious

. DRUG ABUSE ______34. Which of these statements is NOT a drug myth? a. I can quit whenever I want. b. Cigarettes are not addictive. c. Some people abuse drugs as a way to make friends. d. Alcohol abuse is not as severe as drug abuse.

35. Why does a legal drug user take a drug?

36. What is one reason that a drug abuser takes drugs?

37. The first drugs that a person abuses are called 38. A reason that young people often begin to use drugs is

.

.

Copyright © by Holt, Rinehart and Winston. All rights reserved.

Holt Science and Technology

8

Staying Healthy

Back

Print

Name Class Date

Directed Reading A continued

39. Why do many drug abusers not recognize the dangers of drugs?

40. People who abuse drugs go through physical and

changes.

41. What is the first step to quitting drugs?

42. What are two reasons that getting off drugs can be very difficult?

43. One place people may turn to for help with drug abuse is

a(n)

.

Copyright © by Holt, Rinehart and Winston. All rights reserved.

Holt Science and Technology

9

Staying Healthy

Back

Print

Name Class Date

Skills Worksheet

Directed Reading A

Section: Healthy Habits

TAKING CARE OF YOUR BODY

______ 1. What is the science of preserving and protecting health known as? a. aerobics b. hygiene c. healthiness d. washing

______ 2. What is the best way to prevent the spread of disease? a. using sunscreen b. washing hands c. brushing teeth d. shampooing

3. What are three parts of your body that you should take care of for good hygiene?

4. To have good posture, imagine a(n) 5. How can you maintain good posture at a desk?

passing

through your ear, shoulder, hip, knee, and ankle when you stand.

6. Vigorous, constant activity for 20 minutes or more is known as

.

7. What are three examples of aerobic exercise?

8. Because aerobic exercise increases the heart rate, more

is taken in by the body.

Copyright © by Holt, Rinehart and Winston. All rights reserved.

Holt Science and Technology

10

Staying Healthy

Back

Print

Name Class Date

Directed Reading A continued

9. What are three benefits of regular aerobic exercise?

10. Teenagers need more

than younger children.

11. How many hours of sleep should a teenager get each night?

12. What will you miss out on if you don't get enough sleep?

COPING WITH STRESS ______13. What is the body's physical and mental response to pressure? a. stress c. aerobics b. hygiene d. withdrawal symptoms ______14. What does stress help your body to do? a. sleep c. prepare for difficult situations b. overcome disease d. relax ______15. Which of these is NOT a sign of stress? a. getting upset c. having a headache b. being relaxed d. having trouble sleeping ______16. Which of these is NOT a good way of coping with stress? a. sharing problems c. making a list b. washing hands d. exercising INJURY PREVENTION

17. Injury and even death are caused by 18. What are three safety tips for camping and hiking?

.

19. What are two safety steps for swimming and diving?

Copyright © by Holt, Rinehart and Winston. All rights reserved.

Holt Science and Technology

11

Staying Healthy

Back

Print

Name Class Date

Directed Reading A continued

20. Never touch an electrical switch while also touching

.

21. Have a parent install 22. Never leave objects on

on every floor of the house. or someone may trip

and fall.

23. Keep grease and drippings away from open 24. Keep electrical cords out of 25. In the car, always wear a(n) 26. When riding a bike, always wear a(n) 27. In a lab or woodworking class, always wear the proper

. . . .

.

28. In class, always follow the teacher's

.

WHEN ACCIDENTS HAPPEN

29. If an accident happens, what number can you call for help in most communities?

30. After describing where an accident is, what three things should you be able to describe about the accident?

31. To learn more about helping in emergencies, take a(n)

or CPR course.

32. A person who is not breathing and has no heartbeat can be revived with

.

33. What do you need to be before attempting any lifesaving procedures?

Copyright © by Holt, Rinehart and Winston. All rights reserved.

Holt Science and Technology

12

Staying Healthy

Back

Print TEACHER RESOURCE PAGE

Answer Key

Directed Reading A

SECTION: ASKING ABOUT LIFE

1. life science 2. diversity 3. Answers will vary. Sample answer: 14. Answers will vary. Sample answer: so

other scientists may repeat the experiments to see if they get the same results; so scientists with similar interests can compare hypotheses and form consistent explanations

Where does it live?

4. anyone 5. anywhere--in a laboratory, on farms,

SECTION: SCIENTIFIC MODELS

1. 2. 3. 4. 5. 6. 7. 8.

6. 7. 8. 9.

10.

in forests, on the ocean floor, in space, for business, hospitals, government agencies, universities, as teachers his or her curiosity AIDS inherited Many environmental problems are caused by people's misuse of natural resources. By learning about the needs of Siberian tigers, scientists hope to develop a plan that will help them survive.

C C B A D theory law scientific theories are used to explain observations and to predict what might happen: Scientific law is a summary of observations and tells us what will happen. 9. theories, facts, laws

SECTION: SCIENTIFIC METHODS

1. making observations; forming a 2. 3. 4. 5. 6. 7.

SECTION: TOOLS, MEASUREMENT, AND SAFETY

1. Life scientists use tools to make obser-

8. 9. 10.

11. 12.

13.

hypothesis The order depends on what works best to answer their questions. B hypothesis testable prediction an experiment that tests only one factor at a time by using a comparison of a control group with one or more experimental groups a factor that differs between the control group and experimental groups planning The more organisms tested, the more certain scientists can be of the data they collect in an experiment. Answers will vary. Sample answer: in a graph or a data table Both are helpful. Either way, the scientist has learned something, which is the purpose of using scientific methods. another investigation

2. 3. 4.

5. 6. 7. 8. 9. 10.

11. 12. 13. 14. 15. 16.

vations and to gather, store, and analyze information. the application of science for practical purposes 1946 to create graphs, solve complex equations, analyze data, share data and ideas, and publish reports B D C A C It helps scientists share and compare observations and results. Almost all units are based on the number 10, which makes conversions easy. millimeter area square volume liters, milliliters, cubic meters, cubic centimeters, and cubic millimeters mass

Copyright © by Holt, Rinehart and Winston. All rights reserved.

Holt Science and Technology

95

The World of Life Science

Back

Print TEACHER RESOURCE PAGE

17. kilograms, metric tons, and grams 18. temperature 19. degrees Celsius, degrees Fahrenheit, 20.

SECTION: TOOLS, MEASUREMENT, AND SAFETY

1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14. 15. 16. 17. 18. 19. 20.

21. 22. 23. 24. 25. 26. 27. 28. 29.

and kelvins Sample answer: Ask teacher for permission and read the lab procedure carefully. B D C G F I E A H

Directed Reading B

SECTION: ASKING ABOUT LIFE

1. 2. 3. 4. 5.

B A D D C

6. 7. 8. 9.

B diseases inherited tigers

tools technology computer analyze data B D C A B C A A C D A B D B C A

Vocabulary and Section Summary

SECTION: ASKING ABOUT LIFE

1. life science: the study of living things

SECTION: SCIENTIFIC METHODS

1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14. 15.

scientific methods asking questions counting accurate hypothesis if-then factor controlled experiment variable A A A C A B

7. 8. 9. 10. 11.

SECTION: SCIENTIFIC METHODS

1. scientific methods ­ a series of steps

followed to solve problems 2. hypothesis: an explanation that is based on prior scientific research or observations and that can be tested 3. controlled experiment: an experiment that tests only one factor at a time by using a comparison of a control group with an experimental group 4. variable: a factor that changes in an experiment in order to test a hypothesis

SECTION: SCIENTIFIC MODELS

1. model: a pattern, plan, representation,

SECTION: SCIENTIFIC MODELS

1. 2. 3. 4. 5. 6.

A B A C A A

B B B D A

or description designed to show the structure or workings of an object, system, or concept 2. theory: an explanation that ties together many hypotheses and observations

Copyright © by Holt, Rinehart and Winston. All rights reserved.

Holt Science and Technology

96

The World of Life Science

Back

Print TEACHER RESOURCE PAGE

Answer Key

Directed Reading A

SECTION: CHARACTERISTICS OF LIVING THINGS

1. 2. 3. 4. 21. metabolism 22. The cell gets larger and divides, which

makes other organisms.

23. The number of cells increases, and the

5.

6. 7. 8.

9. 10.

11. 12.

13. 14. 15. 16. 17. 18. 19. 20.

cell cells membrane Answers will vary. Sample answer: A cell contains all of the materials necessary for life. Answers will vary. Sample answer: The cell's membrane separates the contents of a cell from the surrounding environment. Different kinds of cells perform specialized functions. stimulus Answers will vary. Sample answer should include three of the following: chemicals, gravity, light sounds, hunger, touch, anything that causes a response homeostasis Answers will vary. Sample answer: Many chemical reactions that keep an organism alive can take place only when conditions are just right, so the organism's internal conditions must stay stable. It's trying to return itself to its normal temperature. Answers will vary. Sample answer: Animals control their temperatures by changing their environments. When they get too hot they move to the shade. When they get too cold, they move into the sunlight. sexual asexual asexual sexual A C heredity Answers will vary. Sample answer should include three of the following: making food, breaking down food, moving materials into and out of cells, building cells

organism gets bigger. 24. Answers will vary. Sample answer: As they grow, living things may develop and change, passing through different stages on their way to adulthood.

SECTION: THE NECESSITIES OF LIFE

1. 2. 3. 4. 5. 6. 7. 8. 9.

10.

11.

12.

13. 14. 15. 16. 17. 18. 19.

20. 21. 22. 23. 24. 25. 26.

water, air, a place to live, food D C three days B A D photosynthesis Answers will vary. Sample answer: All organisms need all the things they need to survive in the place where they live. Answers will vary. Sample answer: They compete for food, water, and other necessities. Answers will vary. Sample answer: Food gives organisms energy and the raw materials needed to perform life processes. Answers will vary. Sample answer: Organisms use nutrients to replace cells and to build body parts. C D C P P D Answers will vary. Sample answer: Organisms break down food in order to use the nutrients in it. molecules compounds proteins, carbohydrates, lipids, ATP, nucleic acids C A D B

It's Alive!! Or Is It?

Copyright © by Holt, Rinehart and Winston. All rights reserved.

Holt Science and Technology

80

Back

Print TEACHER RESOURCE PAGE

27. carbohydrates 28. Cells use carbohydrates as a source of 17. 18. 19. 20. 21. 22. 23. 1. 2. 3. 4. 9. 10. 11. 12. 13. 14. 15. 16. 17. 18. 19. 20. 21. 22. 23. 24. 25. 26. 27. 28. 29. 30. 31. 32. 33.

energy and for energy storage.

29. simple carbohydrates 30. Answers will vary. Sample answer:

table sugar or sugar in fruits

31. complex carbohydrate 32. Answers will vary. Sample answer:

offspring heredity D C A A B D C B A producers plant consumers frog decomposers mushroom nutrients molecule proteins amino acids hemoglobin enzyme carbohydrate energy simple fruits complex starch C B A C A D D 5. 6. 7. 8. B D D B

33. 34. 35.

36.

37. 38.

39. 40.

When I eat mashed potatoes, I am eating a potato's stored starch. Starch is a complex carbohydrate. A phospholipids Answers will vary. Sample answer: An organism that has used up most of its carbohydrates can get energy from two lipids, fats and oils. Answers will vary. Sample answer: At room temperature, most fats are solids and most oils are liquids. Most lipids stored in plants are oils. Most lipids stored in animals are fats. ATP Answers will vary. Sample answer: The energy in carbohydrates and lipids is transferred to ATP, which then provides fuel for cellular activities. nucleic acids Answers will vary. Sample answer: Nucleic acids contain all the information needed for a cell to make proteins. DNA is a nucleic acid.

SECTION: THE NECESSITIES OF LIFE

Directed Reading B

SECTION: CHARACTERISTICS OF LIVING THINGS

1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14. 15. 16.

C B C A D A stimulus stable homeostasis shiver reproduce sexual asexual single-celled DNA cells

Vocabulary and Section Summary

SECTION: CHARACTERISTICS OF LIVING THINGS

1. cell: the smallest unit that can perform

all life processes; cells are covered by a membrane and have DNA and cytoplasm 2. stimulus: anything that causes a reaction or change in an organism or any part of an organism 3. homeostasis: the maintenance of a constant internal state in a changing environment

Copyright © by Holt, Rinehart and Winston. All rights reserved.

Holt Science and Technology

81

It's Alive!! Or Is It?

Back

Print TEACHER RESOURCE PAGE

Answer Key

Directed Reading A

SECTION: THE DIVERSITY OF CELLS

1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 7. B 8. to keep the cell's membrane from col-

11. 12. 13. 14. 15. 16. 17. 18. 19.

20. 21. 22. 23. 24. 25. 26. 27. 1. 2. 3. 4.

cell C D A E B C A B All organisms are made of one or more cells. The cell is the basic unit of all living things. All cells come from existing cells. cell of plants and fungi B E D A C cell membranes, organelles, cytoplasm, and DNA eukaryotic and prokaryotic Prokaryotes are organisms that consist of a single cell that does not have a nucleus or membrane-bound organelles. eubacteria, or bacteria tiny, round organelles made of protein and other material Archaebacterial ribosomes are different from eubacterial ribosomes heat-loving, salt-loving, and methane-making D B A "many cells"

lapsing and to help its organelles move C A D ribosomes amino acids endoplasmic reticulum or ER smooth, rough A a mitochondria ATP B C C B a vesicle a lysosome is a vesicle responsible for digestion inside a cell. 25. Lysosomes destroy worn-out or damaged organelles, get rid of waste materials, and protect the cell from foreign invaders. 26. Vacuoles are large organelles that act like lysosomes or store water and other materials.

9. 10. 11. 12. 13. 14. 15. 16. 17. 18. 19. 20. 21. 22. 23. 24.

SECTION: THE ORGANIZATION OF LIVING THINGS

1. by making more cells 2. larger size, longer life, and

specialization

3. A tissue is a group of similar cells that 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14. 15.

SECTION: EUKARYOTIC CELLS

to give support to a cell cellulose chitin or a chemical similar to chitin a protective layer that encloses the cell and separates the cell's contents from the cell's environment. 5. lipids, phospholipids, and proteins 6. proteins and lipids

perform a common function. nerve, muscle, connective, protective transport, protective, ground organ organ system leaves, stems, roots D B A D structure function alveoli

Copyright © by Holt, Rinehart and Winston. All rights reserved.

Holt Science and Technology

85

Cells: The Basic Units of Life

Back

Print TEACHER RESOURCE PAGE

Answer Key

Directed Reading A

SECTION: EXCHANGE WITH THE ENVIRONMENT

1. Like a factory, an organism must 9. 10. 11. 12. 13.

2. 3. 4. 5. 6. 7. 8.

9. 10. 11. 12. 13. 14. 15. 16. 17.

18. 19.

20. 21.

obtain energy and raw materials and get rid of wastes diffusion water molecules osmosis water particles move to where they are less concentrated osmosis The water will move out of the cells to where water molecules are less concentrated in the salty solution. The cells will shrivel up. Osmosis makes the plant firm again. C A B D E proteins endocytosis The cell surrounds a large particle and encloses it in a vesicle to bring the particle into the cell. exocytosis The cell forms a vesicle around the large particle and the vesicle carries the particle to the cell membrane. The vesicle fuses with the membrane and releases the particle to the outside of the cell. C, A, B B, A, C

14.

15.

16. 17. 18.

19.

20. 21.

22. 23. 24. 25. 26. 27.

Glucose is a plant's "food." glucose, oxygen cellular respiration fermentation Breathing allows many organisms to take in oxygen and get rid of CO2. The oxygen supplied to the cells helps them perform cellular respiration. Food, such as glucose, is broken down into CO2 and H2O, and energy is released. My body uses the energy released during cellular respiration to maintain my temperature. energy mitochondria In cellular respiration, cells use oxygen to break down glucose and release energy and CO2, H2O, and energy. When I exercise strenuously, my muscles don't receive enough oxygen needed for cellular respiration. Fermentation produces lactic acid, which contributes to muscles fatigue. Another type of fermentation occurs in some types of bacteria and in yeasts. Yeast forms carbon dioxide (CO2) during fermentation. The bubbles of carbon dioxide gas cause the dough to rise. D F B C A E

SECTION: CELL ENERGY

1. When I feel hungry, my body is telling 2. 3. 4. 5. 6. 7. 8.

SECTION: THE CELL CYCLE

1. It is important for your body to

me that my cells need energy. the sun food D photosynthesis pigments chlorophyll a simple sugar or carbohydrate

2. 3. 4.

5.

produce millions of new cells because this allows you to grow and replace cells that have died. A B Before it divides, a cell must make a copy of its deoxyribonucleic acid (DNA). the copying of chromosomes

Copyright © by Holt, Rinehart and Winston. All rights reserved.

Holt Science and Technology

89

The Cell in Action

Back

Print TEACHER RESOURCE PAGE

6. 7. 8. 9. 10. 11. 12. 13. 14. 15. 16.

17. 18. 19. 20. 21.

22.

23.

24. 25. 26. 27. 28. 29. 30. 31.

32. 33. 34.

prokaryotic eukaryotic prokaryotic eukaryotic prokaryotic binary fission the circle of DNA DNA 46, 8, 48 homologous chromosomes Homologous chromosomes have the same sequence of genes and the same structure organelles, chromosomes chromatids mitosis Chromatids are held together at a region called the centromere. The cell grows and copies its organelles and chromosomes. The chromosomes split into copies called chromatids.The chromatids twist into an X shape. During the second stage of the cell cycle, the chromatids come apart. This separation is called mitosis. During the third stage of the cell cycle, the cell divides into two cells that are identical to each other and to the original cell. B Phase 3 Phase 2 Interphase Phase 4 Phase 1 Cytokinesis In eukaryotic cells that do not have cell walls, the cell membrane pinches inward until it divides the cytoplasm and splits the cell in two. 3 1 2

5. 6. 7. 8. 9. 10. 11. 12. 13.

D C A C C D A B D

14. 15. 16. 17. 18. 19. 20. 21.

C B B A B B B A

SECTION: CELL ENERGY

1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14. 15. 16. 17.

sun food reproduce the sun food photosynthesis energy C B cellular respiration fermentation D 18. C 19. A 20. D 21. A 22. D

B A A D B

SECTION: THE CELL CYCLE

1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14. 15. 16. 17.

Directed Reading B

SECTION : EXCHANGE WITH THE ENVIRONMENT

1. 2. 3. 4.

C A A C C D less complex more complex binary fission DNA D B B C A B A

18. 19. 20. 21. 22. 23.

C D B C A A

energy and raw materials cell membrane healthy wastes

Copyright © by Holt, Rinehart and Winston. All rights reserved.

Holt Science and Technology

90

The Cell in Action

Back

Print TEACHER RESOURCE PAGE

Answer Key

Directed Reading A

SECTION: MENDEL AND HIS PEAS

1. The passing of traits from parents to 10. 11. 12. 13. 14. 15. 16. 17. 18. 19. 20. 21. 22.

offspring

2. Answers will vary. Sample answer: I 3. 4. 5. 6. 7. 8. 9. 10.

11. 12. 13.

14.

15. 16. 17. 18. 19. 20. 21.

have brown eyes like my mother. B C A self-pollinating true-breeding cross-pollinate wind, insects Answers will vary. Sample answer: Self-pollinating was important because it allowed Mendel to grow true-breeding plants. Cross-pollination was important because he could mix different traits to check results. characteristic traits Answers will vary. Sample answer: True-breeding plants are important because he then knew what to expect if his plants self-pollinated. Answers will vary. Sample answer: Mendel removed the anthers of one plant so that the plant could not self-pollinate. He then did the cross-pollinating himself. C B A B A C D

23. 24.

F D C E Pp It will be passed on to the next generation. PP, Pp, pP Pp, pP C 25% There are only two possibilities for each trait. incomplete dominance Answers will vary. Sample answer: A cross between a true-breeding red snapdragon and a true-breeding white snapdragon produces pink flowers, because both alleles of the gene have some degree of influence. trait environment

SECTION: MEIOSIS

1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14. 15. 16. 17. 18. 19. 20. 21. 22. 23. 24.

SECTION: TRAITS AND INHERITANCE

1. 2. 3. 4. 5. 6. 7. 8. 9.

C D A B A B H A B

C B one C A B B meiosis 46 nucleus genes Two identical copies of the original cell are formed. C A B D 3 5 8 1 7 4 6 2

Copyright © by Holt, Rinehart and Winston. All rights reserved.

Holt Science and Technology

91

Heredity

Back

Print TEACHER RESOURCE PAGE

25. half the number of chromosomes that 26. 27. 28. 29. 30. 31. 32. 33. 34. 35. 36. 37. 38.

were present in the original cell meiosis genotype sex chromosomes two X chromosomes one X and one Y chromosome the X chromosome the Y chromosome They are more likely to have a sex-linked disorder. Answers will vary. Sample answer: color blindness and hemophilia pedigree carrier recessive selective breeding

Directed Reading B

SECTION: MENDEL AND HIS PEAS

1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14. 15.

B B D C A C B B C A dominant recessive D B A

12. 13. 14. 15. 16. 17. 18. 19. 20. 21. 22.

4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14. 15. 16. 17. 18. 19. 20. 21. 22. 23. 24. 25.

C B B B B D C D B A C B A D meiosis X chromosomes Y chromosome hemophilia pedigree carriers recessive selective breeding

Vocabulary and Section Summary

SECTION: MENDEL AND HIS PEAS

1. heredity: the passing of genetic traits

from parent to offspring

2. dominant trait: the trait observed in

the second generation when parents with different traits are bred 3. recessive trait: a trait that reappears in the third generation after disappearing in the second generation when parents with different traits are bred. A B C D C A B A D B C

SECTION: TRAITS AND INHERITANCE

1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11.

C D A D B B C B D B A

SECTION: TRAITS AND INHERITANCE

1. gene: one set of instructions for an

inherited trait

2. allele: one of the alternative forms of a

SECTION: MEIOSIS

1. C 2. B 3. A

gene that governs a characteristic, such as hair color 3. phenotype: an organism's appearance or other detectable characteristic 4. genotype: the entire genetic makeup of an organism; also, the combination of genes for one or more specific traits 5. probability: the likelihood that a possible future event will occur in any given instance of the event

Copyright © by Holt, Rinehart and Winston. All rights reserved.

Holt Science and Technology

92

Heredity

Back

Print TEACHER RESOURCE PAGE

Answer Key

Directed Reading A

SECTION: WHAT DOES DNA LOOK LIKE?

1. 2. 3. 4. 12. gene 13. Answers will vary. Sample answer:

5. 6. 7. 8. 9. 10. 11. 12. 13. 14. 15. 16. 17. 18. 19. 20. 21. 22. 23. 24. 25. 26. 27. 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11.

D A B give instructions for building and maintaining cells and be able to be copied each time a cell divides Because each cell contains an identical set of genes. complex a sugar, a phosphate and a base adenine, thymine, guanine, cytosine A, T, G, C adenine cytosine X-ray diffraction spiral a long, twisted ladder how DNA is copied and how it functions in the cell double helix alternating sugar and phosphate molecules a pair of bases B A The matching bases are always present in equal amounts. replicate complementary down the middle complementary nucleotides every time a cell divides proteins 1.5 m A C gene 30,000 46 2 DNA bases amino acids protein

14. 15. 16. 17. 18. 19. 20. 21. 22. 23. 24. 25. 26. 27. 28. 29.

30. 31. 32.

33. 34. 35.

Proteins determine how tall you are, what colors you see, whether your hair is curly or straight. ribonucleic acid DNA ribosome messenger RNA transfer RNA 2 4 3 5 1 mutations B A C mutagens Answers will vary. Sample answers: high-energy radiation from Xrays, ultraviolet radiation from sunlight, asbestos, chemicals in cigarette smoke A D Answers will vary. Sample answers: Curing diseases, creating new drugs, new foods, or new fabrics fingerprinting DNA clone

Directed Reading B

SECTION: WHAT DOES DNA LOOK LIKE?

1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12.

SECTION: HOW DNA WORKS

B A C A C nucleotides guanine thymine cytosine B B C

Copyright © by Holt, Rinehart and Winston. All rights reserved.

Holt Science and Technology

77

Genes and DNA

Back

Print TEACHER RESOURCE PAGE

Answer Key

Directed Reading A

SECTION: CHANGE OVER TIME

1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 34. C 35. A

14. 15. 16. 17. 18. 19. 20. 21. 22. 23.

24. 25. 26. 27. 28. 29. 30.

31. 32. 33.

differences B C species population species change characteristics New species form. evolution A D A dead organism is covered by a layer of sediment. Over time, the organism is completely covered. Minerals in the sediment may gradually replace the organism with stone or the organism may leave an imprint on the surrounding rock. the fossil record by the fossils' ages and physical similarities organisms less likely exist B A hypotheses by a branch Answers will vary and may include any two of these: camels, llamas, pigs, peccaries, hoofed grazing animals, and hippopotamuses ancestors tree of life that their knowledge is not complete by examining living organisms Whales breathe air, give birth to live young, and produce milk. tiny hip bones a sequence of fossils in the fossil record between ancient mammals and modern whales B B D

SECTION: HOW DOES EVOLUTION HAPPEN?

1. Scientists learned that Earth is much

2. 3. 4. 5. 6. 7. 8. 9.

10.

11. 12. 13. 14. 15. 16. 17. 18. 19. 20. 21. 22. 23. 24. 25. 26. 27. 28. 29. 30. 31.

older than previously thought, gradual processes have changed Earth's surface, and that Earth had a fossil record. A B Galápagos Islands Their beaks were different. obtaining food D C The finches were descended from South American finches blown to the islands by a storm. Over many generations, the finches adapted to life on the island. He spent many years analyzing evidence and gathering other people's ideas. C A B to produce plants and animals with desired traits to produce stronger or quicker horses to produce larger fruit offspring competition survive evolve that the Earth was old enough to allow for slow changes On the Origin of Species by Means of Natural Selection natural selection C A B D how organisms inherit traits, or why organisms show so much variation genes offspring selection

Copyright © by Holt, Rinehart and Winston. All rights reserved.

Holt Science and Technology

81

The Evolution of Living Things

Back

Print TEACHER RESOURCE PAGE

Answer Key

Directed Reading A

SECTION: EVIDENCE OF THE PAST

1. D 2. Answers will vary. Sample answer: 23. 24. 25. 26. 27.

3.

4. 5. 6. 7. 8.

9. 10. 11. 12. 13. 14.

15. 16.

17. 18.

19.

20. 21. 22.

Fossils show us life on earth has changed a great deal; fossils provide clues about how changes happened. Answers will vary. Sample answers: Fossils are traces or imprints of living things preserved in rock; remains or physical evidence of an organism preserved by geological processes. 3 2 1 relative dating Answers will vary. Sample answer: the bottom layers because those were formed first absolute dating atoms energy, smaller particles, or both half-life the approximate age of the rock Answers will vary. Sample answer: the span of time from the beginning of Earth to the present is very long. geologic Answers will vary. Sample answer: they put the fossil in chronological order with other fossils; by looking at the fossils in order they can see the changes over time. eras Answers will vary. Sample answer: Eras began with a change in the type of organism that was most dominant. As paleontologists find evidence of different dominant life they add more details to the geologic time scale. extinct mass extinctions Answers will vary. Sample answer: Dinosaurs may have become extinct because of temperature changes caused by a giant meteorite hitting earth or because of forces within the Earth causing volcanoes or earthquakes.

B C C D Answers will vary. Sample answer: Slow changes give time for organisms to adapt. Sudden changes may cause mass extinctions. 28. Answers will vary. Sample answer: Conditions on Earth have changed many times and life changes with conditions.

SECTION: ERAS OF THE GEOLOGIC TIME SCALE

1. Precambrian, Paleozoic, Mesozoic,

Cenozoic

2. B 3. Answers will vary. Sample answer:

4.

5. 6. 7. 8. 9. 10.

11.

12.

13. 14. 15. 16.

The atmosphere was made of gases such as water vapor, carbon dioxide and nitrogen; it was a place of great turmoil with volcanoes, meteorites, and violent storms. Answers will vary. Sample answer: Energy from radiation and storms may have caused a reaction in simple chemicals; eventually molecules became cells. prokaryotes cyanobacteria eukaryotes ozone C Answers will vary and may include three of these: sponges, corals, snails, clams, squids, trilobites, fishes, sharks. Answers will vary. Sample answer: At first scientists thought the earliest forms of life were from that time. Answers will vary and may include three of these: ferns, club mosses, horsetails, conifers. 2 1 3 The largest known mass extinction wiped out entire categories of marine organisms.

Copyright © by Holt, Rinehart and Winston. All rights reserved.

Holt Science and Technology

81

The History of Life on Earth

Back

Print TEACHER RESOURCE PAGE

17. 18. 19. 20. 21. 22. 23. 24. 25.

26.

B "middle life" Age of Reptiles Answers will vary. Sample answer: dinosaurs, lizards, birds 65 million years ago B C A Answers will vary and may include: mastodons, sabertoothed cats, camels, ground sloths, horses and any modern animals. Answers will vary. Sample answer: Ice sheets and glaciers extended from the Earth's poles and many organisms migrated toward the equator. Other organisms adapted to the cold. Some organisms became extinct.

17. 18. 19. 20.

Neanderthals and Homo sapiens they disappeared (became extinct) Homo sapiens Answers will vary. Sample answer: the preserved villages and burial grounds. 21. Answers will vary. Sample answer: They learn new things as they find more hominid fossils and more evidence.

Directed Reading B

SECTION: EVIDENCE OF THE PAST

1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14. 15. 16. 17. 18. 19.

SECTION: HUMANS AND OTHER PRIMATES

1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12.

13.

14. 15.

16.

C B C primates chimpanzee hominids bipedalism B A C australopithecines Answers will vary. Sample answer: Australopithecines had bigger brains, used stone tools, climbed trees, and walked on two legs Answers will vary. Sample answer: Australopithecines had slender bodies, humanlike jaws and teeth and probably lived in forests and grasslands. Other hominids had large bodies and massive teeth and jaws. They lived in tropical forests and probably ate tough plant material. Homo Answers will vary. Sample answer: The group Homo had larger, more complex brains, rounder skulls, and flatter faces than australopithecines, advanced toolmaking abilities and walked upright. Homo Erectus

D B relative absolute atoms C A B A C C B C tectonic plate plate tectonics B C B A

SECTION: ERAS OF THE GEOLOGIC TIME SCALE

1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14. 15. 16. 17. 18. 19.

A C C B A C B C B B B C B B C C C B C

Copyright © by Holt, Rinehart and Winston. All rights reserved.

Holt Science and Technology

82

The History of Life on Earth

Back

Print TEACHER RESOURCE PAGE

Answer Key

Directed Reading A

SECTION: SORTING IT ALL OUT

1. Classification is the division of organ-

2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14. 15. 16. 17. 18. 19. 20. 21.

22. 23. 24. 25. 26. 27. 28. 29. 30. 31. 32. 33.

isms into groups, or classes, based on specific characteristics. B B B C A D A plants and animals Carolus Linnaeus seven They all have hair and mammary glands. They give birth to live young. A D B phyla genus kingdom, phylum, class, order, family, genus, species scientific name Before Linnaeus, scholars used names that had as many as 12 words to identify species. The system was difficult because scientists didn't always refer to organisms using the same names. Carolus Linnaeus genus capital letter lowercase letter organism Latin, Greek species T. rex Felis domesticus C dichotomous key Answers will vary. Sample answer: A dichotomous key uses paired statements to help someone find the identity of a mystery organism. The two paired statements are different from each other, such as "this mammal has

wings and flies" and "this mammal does not fly and has no wings." The person would choose the statement which fits the organism. Beside each statement is a direction that will take the person to another set of statements. The person chooses the best statement from this pair, is given directions to go to another set, and so on. Soon, there are no more statements, and the person can then see the identify of the organism. 34. C 35. D 36. A

SECTION: THE SIX KINGDOMS

1. 2. 3. 4. 5. 6. 7.

8. 9. 10. 11. 12. 13. 14. 15. 16. 17. 18. 19. 20. 21. 22. 23.

24. 25.

plants, animals D B C A protista Answers will vary. Sample answer: I don't think there will always be six kingdoms for classifying organisms because scientists haven't found all the organisms that exist, and some might not fit into the present kingdoms. prokaryotes archaebacteria, eubacteria Eubacteria Eubacteria Archaebacteria Archaebacteria Eubacteria C protozoans algae slime mold A B B molds and mushrooms Members of kingdom Plantae are green, multicellular, have cell walls, and make their own food using the sun's energy. light land, water

Classification

Copyright © by Holt, Rinehart and Winston. All rights reserved.

Holt Science and Technology

80

Back

Print TEACHER RESOURCE PAGE

26. The sugar, or glucose, that plants

27.

28. 29. 30. 31. 32.

33.

make for themselves is also important to other organisms because some, such as animals, eat the plants and others, such as fungi, absorb and digest dead plant material that contains the glucose. Besides making food for other organisms, plants such as trees, grasses, and bushes can be habitat for birds, insects, and other animals. C C animals Animals may eat plants, and some use them for habitat. Animals depend on bacteria and fungi to recycle nutrients found in dead organisms. sponges

Directed Reading B

SECTION: SORTING IT ALL OUT

1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14. 15. 16. 17. 18. 19. 20. 21. 22. 1. 2. 3. 4. 5. 6.

B B D C A C D B A B kingdoms classes genera species C B D B B C D A A D C D B B

7. 8. 9. 10. 11. 12. 13. 14. 15. 16. 17. 18. 19. 20. 21. 22. 23. 24. 25. 26. 27. 28. 29. 30. 31.

B D C A C D C eukaryotes protists algae protozoans kingdom Euglena C A C A B A C D C B A B

Vocabulary and Section Summary

SECTION: SORTING IT ALL OUT

1. classification: the division of organ-

isms into groups, or classes, based on specific characteristics 2. taxonomy: the science of describing, naming, and classifying organisms 3. dichotomous key: an aid that is used to identify organisms and that consists of the answers to a series of paired statements.

SECTION: THE SIX KINGDOMS

1. Archaebacteria: a kingdom made up

SECTION: THE SIX KINGDOMS

of bacteria that live in extreme environments 2. Eubacteria: a kingdom that contains all prokaryotes except archaebacteria 3. Protista: a kingdom of mostly onecelled eukaryotic organisms that are different from plants, animals, bacteria, and fungi

Copyright © by Holt, Rinehart and Winston. All rights reserved.

Holt Science and Technology

81

Classification

Back

Print TEACHER RESOURCE PAGE

Answer Key

Directed Reading A

SECTION: BACTERIA

1. 2. 3. 4. 5. 6. 7. 15. 16. 17. 36. archaebacteria 37. one with little or no oxygen 38. Answers will vary. Sample answer: hot

18. 19. 20. 21.

22. 23. 24. 25. 26. 27. 28. 29. 30. 31. 32. 33. 34. 35.

D 8. B C 9. C A 10. A B 11. flagella A 12. nucleus C 13. prokaryote D 14. eukaryote Answers will vary. Sample answer: move; get energy; reproduce binary fission Answers will vary. Sample answer: Bacteria reproduce by binary fission through three steps. (1) The cell's DNA is copied and binds to the cell membrane. (2) The DNA and its copy separate as the cell and membrane grow. (3) When the cell is about double its original size, the membrane pinches inward. A new cell wall forms and separates the two new cells. Answers will vary. Sample answer: moist, warm places Answers will vary. Sample answer: dry or cold places endospore Answers will vary. Sample answer: Bacteria can surround their own bodies with a thick, protective membrane called an endospore, which allows them to remain inactive until conditions are favorable for growth. D C C A B C A energy in sunlight cyanobacteria pigments Answers will vary. Sample answer: by eating red cyanobacteria C A B

springs at Yellowstone National Park; below ice in Antarctica; far below the Earth's surface 39. Answers will vary. Sample answer: Many archaebacteria do not have cell walls. Archaebacteria with cell walls have a different kind than those eubacteria have. Archaebacteria also often live where nothing else can live.

SECTION: BACTERIA'S ROLE IN THE WORLD

1. Answers will vary. Sample answer:

2. 3. 4. 5. 6.

7. 8.

9.

10. 11.

12. 13. 14. 15.

16. 17.

Bacteria live in water, air, and the human body. D B C Answers will vary. Sample answer: It's in a form they can't use. Answers will vary. Sample answer: Nitrogen-fixing bacteria take in nitrogen from the air and change its form. nitrogen fixation Answers will vary. Sample answer: Decomposer bacteria break down dead plants and animal matter. Answers will vary. Sample answer: It makes nutrients available to other living things. bioremediation Answers will vary. Sample answer: Some bacteria change harmful chemicals into harmless ones. B C lactose Answers will vary. Sample answer: Bacteria break down the sugar in milk, or lactose, and change it into lactic acid. antibiotics bacteria

Copyright © by Holt, Rinehart and Winston. All rights reserved.

Holt Science and Technology

85

Bacteria and Viruses

Back

Print TEACHER RESOURCE PAGE

18. Answers will vary. Sample answer: 15. Answers will vary. Sample answer: The

19. 20.

21.

22. 23. 24. 25. 26. 27.

28.

Genes are put into bacteria so that it makes insulin and then the insulin is separated from the bacteria for use by people who have diabetes. genetic engineering Answers will vary. Sample answer: They put genes from a frog into the bacterium Escherichia coli. The bacterium then started making copies of the frog genes. Answers will vary. Sample answer: products such as insecticides, cleansers, and adhesives A B B D A Answers will vary. Sample answer: plants, animals, protists, fungi, other bacteria Answers will vary. Sample answer: Plants can be treated with antibiotics. Some plants also have been genetically engineered to be resistant to diseases caused by bacteria.

16. 17. 18. 19. 20.

21.

22.

23. 24. 25. 26. 27. 28. 29.

SECTION: VIRUSES

1. A 2. Answers will vary. Sample answer:

30. 31.

3. 4. 5.

6.

7. 8. 9. 10. 11. 12.

13. 14.

chickenpox, acquired immune deficiency syndrome (AIDS), common cold, flu A C Answers will vary. Sample answer: Viruses are so small and they change so often that it makes it hard to tell how many types there are. Answers will vary. Sample answer: Viruses are hard to fight because they are so small and change so often. L N N N L Answers will vary. Sample answer: Viruses can reproduce only inside a living cell that acts as a host. host Answers will vary. Sample answer: It forces the cell to make viruses rather than healthy new cells.

32.

33.

characteristics that scientists use to group viruses are shape, the type of disease they cause, their life cycle, and the kind of genetic material they contain. C B D A Answers will vary. Sample answer: It protects its genetic material and helps a virus enter a host cell. Answers will vary. Sample answer: viruses that cause warts and chickenpox Answers will vary. Sample answer: viruses that cause colds and flu and HIV, which causes AIDS C 3 4 2 1 lysogenic Answers will vary. Sample answer: In the lysogenic cycle, new viruses are not produced immediately. lysogenic Answers will vary. Sample answer: Viruses are hard to treat because antibiotics don't kill them. Answers will vary. Sample answer: Antiviral medications stop viruses from reproducing. Answers will vary. Sample answer: People can get vaccinations, wash their hands to prevent infection, and never touch wild animals.

Directed Reading B

SECTION: BACTERIA

1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12.

B C A B A C B C A flagella nucleus prokaryote

13. 14. 15. 16. 17. 18. 19. 20. 21. 22. 23. 24.

eukaryote binary fission endospore D B C A B A C D D

Bacteria and Viruses

Copyright © by Holt, Rinehart and Winston. All rights reserved.

Holt Science and Technology

86

Back

Print TEACHER RESOURCE PAGE

Answer Key

Directed Reading A

SECTION: PROTISTS

1. 2. 3. 4. 5. 25. An infected mosquito bites a human

6.

7. 8. 9. 10. 11. 12. 13. 14. 15. 16.

17.

18. 19. 20. 21. 22.

23.

24.

C D eukaryotic Answers will vary. Sample answer: ulvar, pretzel slime mold Answers will vary. Sample answer: Some protists produce their own food. Some protists control their own movement. Some protists eat decaying matter. Protists are less complex than other eukaryotic organisms. They do not have specialized tissues. A photosynthesis Protists can make their own food or eat other organisms. producer heterotrophs parasites host decomposers Heterotrophs eat bacteria, yeast, and other protists. by eating small organisms, by breaking down rotting matter, and by invading other organisms to get its nutrients A parasite damaged most of the potatoes in Ireland in the mid,1800s causing starvation. A B C A Two individuals join together and exchange genetic material by using a small second nucleus. Then, they divide to produce four protists that have new combinations of genetic material. If there is little food or water, a protist that normally reproduces asexually will reproduce sexually until conditions improve. P. vivax, the protist that causes malaria

and releases P. vivax. The liver cells are infected, it reproduces, and the P. vivax enters the blood. The P. vivax invades red blood cells, grows, and the cells open with P. vivax in another form. A mosquito bites a human and picks up the P. vivax. It matures in the mosquito until it bites another human.

SECTION: KINDS OF PROTISTS

1. producers, heterotrophs that move, 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14.

15. 16.

17. 18. 19. 20. 21. 22. 23. 24.

heterotrophs that don't move B D B B A F B C G E D A Answers will vary. Sample answer: water, moist soil, melting snow, on tree trunks colonies Answers will vary. Sample answer: seaweeds in cool climates are brown algae; they attach to rocks and form large floating beds in water; some grow 60 m in one season; only the tops are exposed to sunlight in both salt water and fresh water cellulose flagella photosynthesis, consumers, decomposers, parasites because they can get food in several ways A fresh and salt water, in soil, and as parasites in animals for moving and for catching food

Copyright © by Holt, Rinehart and Winston. All rights reserved.

Holt Science and Technology

90

Protists and Fungi

Back

Print TEACHER RESOURCE PAGE

25. When the amoeba surrounds its food 11. In one type the hyphae break apart

26.

27. 28. 29. 30. 31. 32. 33. 34. 35.

36. 37.

38. 39. 40. 41.

with is pseudopodia a food vacuole is formed. Enzymes move into the vacuole to digest the food and the digested food then passes to the amoeba. It is also used to help remove waste. A B C E D when one organism lives closely with another and they both benefit to help a ciliate move and feed micronucleus Answers will vary. Sample answer: Spore-forming protists are parasites and they have no cilia or flagella. in moist soil or other organisms as decomposers eating dead matter, or as parasites using living plants, animals, algae, or fungi as hosts Slime molds look like thin, colorful, shapeless globs of slime. yeast spores Spores develop into new slime molds when stressful environmental conditions improve.

12. 13. 14. 15. 16. 17. 18.

19. 20. 21. 22.

SECTION: FUNGI

1. Fungi are eukaryotic heterotrophs

2.

3. 4.

5. 6. 7. 8. 9. 10.

that have rigid cell walls and no chlorophyll. Fungi get nutrients by secreting digestive juices onto a food source and then absorbing the dissolved food. decomposers, parasites The plant provides nutrients to the fungus and the fungus protects the plant from disease causing organisms. C D A B eukaryotic underneath the ground

23. 24. 25. 26. 27. 28. 29. 30. 31. 32. 33. 34. 35. 36. 37.

38. 39.

40.

and each new piece becomes a new fungus. In the second type, spores are produced and will grow into a new fungus. sex cells C A A B threadlike, sac, club, imperfect They reproduce asexually when the sporangia break open and release spores. They reproduce sexually when a hypha from one individual joins another hypha. The hyphae grow into specialized sporangia that release sexual spores. sac fungi yeasts, powdery mildews, truffles, morels ascus Answers will vary. Sample answer: Yeasts are used in making bread. Sac fungi are also used as sources of antibiotics. C E D B F H G They usually grow at the edges of the mass of hyphae. gill club sexually athlete's foot A C The protective wall of a lichen keeps water inside them and keeps them from drying out. because they only need air, light, and minerals to grow Lichens make acid that makes cracks in rocks. Dead lichens fall in the cracks and form soil so other organisms can grow in the soil. Lichens absorb water and minerals from the air.

Copyright © by Holt, Rinehart and Winston. All rights reserved.

Holt Science and Technology

91

Protists and Fungi

Back

Print TEACHER RESOURCE PAGE

Answer Key

Directed Reading A

SECTION: WHAT IS A PLANT?

1. Almost all food is made from plants or 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14. 15. 16. 17. 18. 19. 7. club mosses 8. rhizome 9. The fern gametophyte is tiny, green,

from animals that eat plants. B C C C E A D B sporophyte gametophytes sporophyte F A E B C D Answers will vary. Sample answers: Modern green algae and plants contain the same kinds of chlorophyll. They both make food through photosynthesis. They both store energy as starch. They both have a two-stage life cycle. They have similar cell walls.

and heart-shaped. fiddleheads C F H D G A B E Answers will vary. Sample answers: They help form soil. They help prevent soil erosion. In rocky areas, ferns can play a role in the formation of communities. Ferns add to soil depth, which allows other plants to grow. 20. Answers will vary. Sample answer: ferns and some club mosses 21. Answers will vary. Sample answer: fiddleheads of some ferns, young horsetail shoots and roots 22. Their remains formed coal, which is used for energy.

10. 11. 12. 13. 14. 15. 16. 17. 18. 19.

SECTION: SEED PLANTS

1. Answers will vary. Sample answer:

SECTION: SEEDLESS PLANTS

1. nonvascular plants: liverworts,

2. 3. 4. 5. 6.

mosses, hornworts; seedless vascular plants: horsetails, ferns, club mosses B C C D Answers will vary. Sample answer: They are usually the first plants to live in a new environment. When they die, they form a thin layer of soil that new plants can grow in. They reduce soil erosion. They are food for some animals. Some animals use them for nesting material. Humans can dry and burn some types of nonvascular plants as a fuel. Some types of nonvascular plants are used in potting soil.

2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12.

Gymnosperms do not have flowers or fruits. Angiosperms have flowers and fruits and the fruits protect the seeds. seed plants seed plants seedless plants seed plants seed plants seed plants E D A B C

Copyright © by Holt, Rinehart and Winston. All rights reserved.

Holt Science and Technology

108

Introduction to Plants

Back

Print TEACHER RESOURCE PAGE

13. Answers will vary. Sample answer:

14. 15. 16. 17. 18. 19. 20. 21. 22. 23. 24. 25. 26. 27. 28.

29. 30. 31. 32. 33. 34. 35.

36.

Seeds have stored food that young plants can use to start growing, while spores do not have stored food. Seeds can be spread by animals, while spores are generally spread by the wind, which is not as efficient as animals. D B A A C D A B cones gametophytes wind forest fires pollination B Answers will vary. Sample answer: Some seeds are carried by the wind. Some fruits are eaten by animals, which discard the seeds. Some fruits, such as burrs, are carried by sticking to animal fur. M M D M D D Answers will vary. Sample answer: A field mouse uses flowering plants directly as food when it eats seeds and berries. An owl uses flowering plants indirectly as food when it eats a field mouse. Answers will vary. Sample answer: major food crops, such as corn, wheat, and rice; as building materials; to make clothing and rope; to make medicines, rubber, and perfume oils

SECTION: STRUCTURES OF SEED PLANTS

1. 2. 3. 4.

5. 6. 7. 8. 9. 10. 11. 12. 13. 14. 15. 16. 17.

18.

19. 20. 21. 22. 23. 24. 25. 26. 27. 28. 29. 30.

31. 32. 33. 34. 35.

B C underground Answers will vary. Sample answer: They supply plants with water and minerals from the soil. They hold plants in the soil. They store surplus food. F H E C G B D A A C A B Answers will vary. Sample answers: clovers, poppies, buttercups, beans, tomatoes, corn Answers will vary. Sample answer: A growth ring is a ring of dark cells, formed by small xylem cells produced in fall, surrounding lighter cells, formed by larger xylem cells produced in spring. C upper epidermis, palisade layer, spongy layer, lower epidermis palisade layer B E D A C F modified leaves insects Answers will vary. Sample answer: Flowers are adaptations for sexual reproduction. sepals petals stamen pistil ovary, ovule

Copyright © by Holt, Rinehart and Winston. All rights reserved.

Holt Science and Technology

109

Introduction to Plants

Back

Print TEACHER RESOURCE PAGE

36. Answers will vary. Sample answers: in

37. 38. 39. 40. 41. 42. 43. 44. 45. 46.

floral arrangements; as food; to make tea; as spices; in perfumes, lotions, and shampoos J A H I C E G B D F

21. D 22. A 23. B 24.flowers 25. pollen 26. fruit 27. wind

28. 29. 30. 31. 32. 33. 34.

seeds fur monocot dicot B C A

SECTION: STRUCTURES OF SEED PLANTS

1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14. 15. 16. 17. 18. 19. 20. 21. 22.

Directed Reading B

SECTION: WHAT IS A PLANT?

1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11.

B C D C C vacuole chloroplast cell membrane cell wall C A

12. 13. 14. 15. 16. 17. 18. 19. 20. 21. 22.

C D A B C A B plants cell walls ancestor photosynthesis

SECTION: SEEDLESS PLANTS

1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11.

C B B C B B C A B A D

12. 13. 14. 15. 16. 17. 18. 19. 20. 21.

A C B silica stems club mosses mosses A A B

A B C C B A C C D C C D D support roots shoots water C A D C A

23. 24. 25. 26. 27. 28. 29. 30. 31. 32. 33. 34. 35. 36. 37. 38. 39. 40. 41. 42. 43. 44.

C B A D C B A C B A A A B pistil ovary stamen D A C broccoli chamomile cloves

Vocabulary and Section Summary

SECTION: WHAT IS A PLANT?

1. nonvascular plants: the three groups

SECTION: SEED PLANTS

1. 2. 3. 4. 5. 6. 7. 8. 9. 10.

A B B A B D A B D A

11. 12. 13. 14. 15. 16. 17. 18. 19. 20.

C D D C A B D B A C

of plants (liverworts, hornworts, and mosses) that lack specialized conducting tissues and true roots, stems, and leaves 2. vascular plant: a plant that has specialized tissues that conduct materials from one part of the plant to another 3. gymnosperm: a woody, vascular seed plant whose seeds are not enclosed by an ovary or fruit 4. angiosperm: a flowering plant that produces seeds within a fruit

Copyright © by Holt, Rinehart and Winston. All rights reserved.

Holt Science and Technology

110

Introduction to Plants

Back

Print TEACHER RESOURCE PAGE

Answer Key

Directed Reading A

SECTION: PHOTOSYNTHESIS

1. C 2. the process by which plants make 3. 4. 5. 6. 7.

SECTION: PLANT RESPONSES TO THE ENVIRONMENT

1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14.

8. 9. 10. 11. 12. 13. 14. 15. 16. 17.

their own food glucose B A chlorophyll Chlorophyll reflects more wavelengths of green light than wavelengths of other colors. Light energy is used to help form glucose. oxygen the process by which cells use oxygen to release energy from food sucrose, starch C A D B C They eat animals that eat plants.

15. 16. 17. 18. 19. 20. 21.

SECTION: REPRODUCTION OF FLOWERING PLANTS

1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14. 15. 16. 17. 18. 29. 20.

C C E, I F or J F or J B G H A D pollination fertilization ovule ovary an inactive seed the sprouting of a seed water, air, and warm temperatures C A B

light, gravity, and changing seasons growth in response to a stimulus plant growth toward a stimulus plant growth away from a stimulus positive tropism negative tropism positive tropism phototropism gravitropism The plant likely would not be able to produce seeds and fruit. Plants respond to the change in length of day and night. short-day plants long-day plants Some leaves are always on the trees. They lose their leaves year-round, a few at a time. All leaves are lost at about the same time every year. deciduous deciduous evergreen deciduous evergreen The chlorophyll breaks down. The yellow and orange pigments in the leaves are then revealed.

Directed Reading B

SECTION: PHOTOSYNTHESIS

1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14.

C D C A chloroplast grana glucose oxygen cellular respiration starch C 15. C A 16. A D 17. B B

Copyright © by Holt, Rinehart and Winston. All rights reserved.

Holt Science and Technology

80

Plant Processes

Back

Print TEACHER RESOURCE PAGE

Answer Key

Directed Reading A

SECTION: WHAT IS AN ANIMAL?

1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14. 15. 16. 17. 18. 19. 20. 21. 22. 23. 24. 25. 26. 27. 12. mating, raising their young, and

finding food

13. Answers will vary. Sample answer:

B D B D vertebrate invertebrates V V I V I V I V I plants multicellular eukaryotic cell walls cell membranes sexually eggs; sperm embryo budding tissues organ search for food; search for shelter; search for mates 28. consumer

resources; territories; food

14. Answers will vary. Correct responses

15. 16. 17. 18. 19. 20. 21. 22. 23. 24. 25. 26.

SECTION: ANIMAL BEHAVIOR

1. 2. 3. 4. 5. 6. 7. 8. 9.

10. 11.

C B D A learned marking territory, defensive action, courtship, and parenting predators prey A frog can be both a predator and a prey. When the frog eats an insect, the frog is the predator; but when a snake eats the frog, the frog is the prey. territory energy; competition

27. 28. 29. 30.

31.

32.

will include three of the following: a dog growling while eating; lions fighting to defend mates; a bird using distraction to defend its offspring; a rabbit freezing to blend into the background; a rabbit outrunning a predator; a bee, ant, or wasp injecting acid into an attacker; a skunk spraying an irritating chemical at a predator; a bird chasing another bird out of its territory courtship parents food hunt C F D A B E migrate to avoid cold weather, to find water, to find food, and to find safe nesting grounds landmarks inactivity; body temperature body fat Answers will vary. Correct responses will include the following information: While an animal hibernates, its temperature, heart rate, and breathing rate drop. The animal may sleep for weeks at a time and survives on stored body fat. Answers will vary. Correct responses will include the following information: No, bears slow down, but do not enter full hibernation. The bear's body temperature does not drop as far as a hibernating animal's does, and the bear sleeps for shorter periods of time than a hibernating animal does. estivation

Copyright © by Holt, Rinehart and Winston. All rights reserved.

Holt Science and Technology

90

Animals and Behavior

Back

Print TEACHER RESOURCE PAGE

33. Answers will vary. Correct responses 23. predators

34. 35. 36. 37.

will include two of the following: so they know when to store food; so they know when to migrate; so they know when to reproduce; so they know when to hibernate; so they know when to sleep; so they know when to undergo cycles of physical changes, like metamorphosis biological clock the length of the day and the temperature circadian rhythms Answers will vary. Sample answer: migration, reproduction

Directed Reading B

SECTION: WHAT IS AN ANIMAL?

1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14. 15. 16. 17. 18. 19. 20. 21. 22.

SECTION: SOCIAL RELATIONSHIPS

1. 2. 3. 4. 5.

6. 7. 8. 9. 10. 11. 12. 13. 14. 15. 16. 17. 18.

19. 20.

21. 22.

social behavior communication language signal Answers will vary. Sample answer: to defend a territory from other members of the species; to find food; to warn others of danger; to identify family members; to frighten predators; to find mates sound, touch, chemicals, sight C E B A D sound can reach many animals over a large area to communicate and to calm and comfort one another pheromones secrete; alarm chemicals; recognition chemicals mate body language Answers will vary. Sample answer: humans smile; a bird may ruffle its feathers; a dog or other animal may show its teeth; fireflies blink signals pride Answers will vary. Sample answer: can spot a predator more quickly; can work together to defend themselves; can hunt together to kill larger prey food, mates They move around in search of food.

B D C B B A D D multicellular eukaryotic cell walls cell membranes B C D C B C D A C A

SECTION: ANIMAL BEHAVIOR

1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14. 15. 16. 17. 18. 19. 20. 21. 22. 23. 24. 25.

innate genes learned flying walking food and water predators prey territory C B A defend predators distraction acid courtship nests parents food hunt Northern Hemisphere monarch butterflies migrate food or water

Copyright © by Holt, Rinehart and Winston. All rights reserved.

Holt Science and Technology

91

Animals and Behavior

Back

Print TEACHER RESOURCE PAGE

Answer Key

Directed Reading A

SECTION: SIMPLE INVERTEBRATES

1. 2. 3. 4. 5. 6. 7. 8.

SECTION: MOLLUSKS AND ANNELID WORMS

1. 2. 3. 4. 5. 6. 7. 8. 9. 10.

9. 10. 11. 12. 13.

14. 15. 16. 17. 18. 19. 20. 21. 22. 23. 24. 25. 26. 27. 28. 29. 30. 31. 32. 33. 34. 35. 36. 37. 38.

invertebrates more than 1 million millions more A tissues symmetry bilateral symmetry, radial symmetry, and asymmetry allow animals to sense their environment and carry messages around the body C E A Sponges cannot make their own food. A sponge sweeps water into its body through its pores. The water brings oxygen and food with it. regenerate reproduce C D B A C polyp and medusa to protect themselves and to catch food medusa polyp polyp corals B planarians, flukes, and tapeworms bilateral sensory lobes parasites B A C C C B They break down dead tissue, which helps make soil rich and healthy.

11.

12. 13. 14. 15. 16. 17. 18.

19. 20.

21. 22.

23. 24. 25. 26. 27.

C B C A B C A ganglia nervous systems a circulatory system in which circulatory fluid is not contained entirely within vessels a circulatory system in which the heart circulates blood though a network of blood vessels that form a closed loop squid and octopus C D A B segmented Annelid worms have a closed circulatory system and a complex nervous system. 100 to 175 They break down animal and plant matter and leave behind castings that enrich the soil. bristles Leeches that are parasites suck the blood of other animals. Leeches that are scavengers eat dead animals. Leeches that are predators eat insects, slugs, and snails. Doctors sometimes use leeches to prevent swelling near a wound. D B C A

SECTION: ARTHROPODS

1. B 2. a segmented body with specialized

parts, jointed limbs, an exoskeleton, and a well-developed nervous system

Copyright © by Holt, Rinehart and Winston. All rights reserved.

Holt Science and Technology

96

Invertebrates

Back

Print TEACHER RESOURCE PAGE

3. 4. 5. 6. 7. 8. 9.

10. 11. 12. 13. 14. 15. 16. 17.

18. 19. 20. 21. 22. 23. 24. 25. 26. 27. 28.

head, thorax, and abdomen foot exoskeleton move protects organs and keeps water inside the body brain Simple eyes can detect light but not see images; compound eyes can see images. B antenna bristles, antenna, and eyes B C D A Centipedes have one pair of legs per segment, while millipedes have two pairs of legs per segment. two pairs of antennae chelicerae head, thorax, and abdomen metamorphosis 3 2 4 1 5 incomplete metamorphosis molting

Directed Reading B

SECTION: SIMPLE INVERTEBRATES

1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14. 15. 16. 17. 18. 19.

A D bilateral symmetry radial symmetry asymmetry C 20. B 21. C 22. A 23. C 24. A 25. B 26. C 27. B 28. D 29. C 30. C 31. A 32. B 33.

D B A C B A B B C B A C C C

SECTION: MOLLUSKS AND ANNELID WORMS

1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11.

SECTION: ECHINODERMS

1. 2. 3. 4.

5. 6. 7. 8. 9. 10. 11. 12. 13. 14. 15.

echinoderms sea stars, sea urchins, and sand dollars endoskeleton Some echinoderms may have long and sharp spines. Other echinoderms may have short and bumpy spines. radial bilateral D nerve ring radial nerve move, eat, breathe, and sense its environment 5 16. B 4 17. D 1 18. A 3 19. C 2

C B C A B C A B A B A

12. 13. 14. 15. 16. 17. 18. 19. 20. 21.

foot visceral mass mantle shell B C B A A D

SECTION: ARTHROPODS

1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13.

C B A D B C D B A C B antenna mandible

14. 15. 16. 17. 18. 19. 20. 21. 22. 23. 24. 25.

gills cephalothorax chelicerae insect A D C B D A E B

Copyright © by Holt, Rinehart and Winston. All rights reserved.

Holt Science and Technology

97

Invertebrates

Back

Print TEACHER RESOURCE PAGE

Answer Key

Directed Reading A

SECTION: FISHES: THE FIRST VERTEBRATES

1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14. 15. 16. 17. 18. 19. 20. 21. 22. 23. 24. 25. 26. 27. 28. 29. 12. 13. 14. 15.

vertebrates A vertebrates tail vertebrae cartilage fish endotherms ectotherms endotherms E A C D fins gill external fertilization B A A C C C B B B D B B

C D salamanders The vocal sac increases the volume of the song. 16. ecological indicators 17. Amphibians' thin skin absorbs chemicals in the water or air. Their lungs take in chemicals from the air. Their body temperature depends on the temperature of the environment.

SECTION: REPTILES

1. Amphibians need to spend part of

2. 3. 4.

5.

SECTION: AMPHIBIANS

1. 2. 3. 4. 5. 6.

7. 8. 9. 10. 11.

an amphibian the ancestors of lungfish-like fishes lung double life Amphibians can absorb water through their thin skin. Amphibians can breathe by gulping air into their lungs and by absorbing oxygen through their skin. brightly colored skin tadpole metamorphosis B A

6. 7. 8. 9. 10. 11. 12. 13. 14. 15.

16. 17.

18.

their lives in or near water; but reptiles can live their whole lives on land. amphibians dinosaurs They have lungs to breathe air. They have thick skin that provides a watertight layer. They use their surroundings to control their temperature. They have a special kind of egg to help them live on land. The skin forms a watertight layer that keeps cells from losing water by evaporation. ectotherms the amniotic egg D B A C E internal fertilization turtles and tortoises, crocodiles and alligators, lizards and snakes, tuataras Tortoises live on land, and turtles spend all or most of their lives in water. their shells An alligator has a broad head and a rounded snout, whereas a crocodile has a narrow head and a pointed snout. snakes and lizards.

Copyright © by Holt, Rinehart and Winston. All rights reserved.

Holt Science and Technology

82

Fishes, Amphibians, and Reptiles

Back

Print TEACHER RESOURCE PAGE

19. Unlike lizards, tuataras do not have 2. endotherm: an animal that can use

visible ear openings, and they are most active when the temperature is low.

Directed Reading B

SECTION: FISHES: THE FIRST VERTEBRATES

1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11.

3.

D C B A C D B B A D C

12. 13. 14. 15. 16. 17. 18. 19. 20. 21.

C B D A B D C A B B

4.

5.

6.

body heat from chemical reactions in the body's cells to maintain a constant body temperature ectotherm: an organism that relies primarily on sources of heat outside of itself lateral line: a faint line visible on both sides of a fish's body that runs the length of the body and marks the location of sense organs that detect vibrations in the water gill: a respiratory organ in which oxygen from the water is exchanged with carbon dioxide from the blood swim bladder: a gas-filled sac that is used to control buoyancy; also known as a gas bladder

SECTION: AMPHIBIANS

1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13.

SECTION: AMPHIBIANS

1. lung: a respiratory organ in which

D lungs amphibian tadpoles metamorphosis C D C D D D A B

oxygen from the air is exchanged with carbon dioxide from the blood 2. tadpole: the aquatic, fish-shaped larva of a frog or toad 3. metamorphosis: a phase in the life cycle of many animals during which a rapid change from the immature form of the organism to the adult form takes place

SECTION: REPTILES

1. amniotic egg: a type of egg that is

SECTION: REPTILES

1. 2. 3. 4. 5. 6. 7. 8. 9.

B C D B C C D B A

10. 11. 12. 13. 14. 15. 16. 17.

A C B D C A A C

surrounded by a membrane, the amnion, and that in reptiles, birds, and egg-laying mammals contains a large amount of yolk and is surrounded by a shell

Section Review

SECTION: FISHES: THE FIRST VERTEBRATES

1. Sample answer: Fishes are vertebrates.

Vocabulary and Section Summary

SECTION: FISHES: THE FIRST VERTEBRATES

1. vertebrate: an animal that has a

backbone

The lateral line system is a row or rows of sense organs along the side of a fish's body. Fishes get oxygen through their gills. A swim bladder is a balloon-shaped organ that fills with gases to help keep bony fishes afloat. 2. Sample answer: An endotherm is an animal that can generate body heat from chemical changes in its cells. An ectotherm is an animal that needs sources of heat outside of itself.

Copyright © by Holt, Rinehart and Winston. All rights reserved.

Holt Science and Technology

83

Fishes, Amphibians, and Reptiles

Back

Print TEACHER RESOURCE PAGE

Answer Key

Directed Reading A

SECTION: CHARACTERISTICS OF BIRDS

1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14. 15. 16. 17. 18. 5. The seven common characteristics of

B A molting down contour They spread their feathers and pant. C A B wings, lightweight bodies, powerful flight muscles, rapid heartbeat lift large sexually brooding B D A C

6. 7.

8.

9. 10. 11. 12. 13. 14.

mammals are the ability to make milk, to breathe oxygen, to be endotherms, to stay warm by having hair, to have specialized teeth, to be able to reproduce sexually, and to use the large brain to learn and think quickly. to feed the young a dome-shaped muscle at the bottom of the rib cage that functions as the main muscle in respiration Being endotherms helps mammals survive in cold areas and stay active in cool weather. hair, fur, blubber canine teeth incisors, molars until they are grown They can think and act quickly in response to events around them. vision, hearing, smell, touch, taste

SECTION: PLACENTAL MAMMALS

1. B 2. placental mammals, monotremes, mar3. 4. 5. 6. 7. 8.

SECTION: KINDS OF BIRDS

1. 2. 3. 4. 5. 6. 7. 8. 9. 10.

D C by running and by swimming B A Its feet automatically close around a branch when it lands in a tree. It will not fall. birds that hunt and eat other vertebrates Answers will vary. Sample answer: mammals, fish, reptiles, insects sharp claws, sharp beaks, good vision

9. 10. 11. 12. 13. 14. 15. 16. 17. 18. 19.

SECTION: CHARACTERISTICS OF MAMMALS

1. 2. 3. 4.

C C A More land and food were available. These resources allowed mammals to spread out and live in different environments.

supials placental uterus placenta gestation C Answers will vary. Sample answers: small, long, pointed noses, small brains to gnaw and chew food They have sharp, gnawing teeth. two sets of incisors in upper jaw, shorter tails bat the use of echoes to find things slicing meat pinnepeds nose, upper lip picking up food, spraying water to cool off a thick, hard pad that covers a mammal's toe, fast runners, large, flat molars for grinding food

Copyright © by Holt, Rinehart and Winston. All rights reserved.

Holt Science and Technology

95

Birds and Mammals

Back

Print TEACHER RESOURCE PAGE

20. 21. 22. 23. 24.

A Both use echolocation to find fish. front flippers and tails seaweed and water plants five fingers on each hand and five toes on each foot; flat fingernails; large brain; forward-facing eyes; opposable thumbs 25. grasping hands and feet, flexible shoulder joints

11. 12. 13. 14. 15. 16. 17. 18. 19. 1. 2. 3. 4. 5. 6. 7. 8.

B D A C C A D precocial altricial C B D C A D C A

SECTION: KINDS OF BIRDS

SECTION: MONOTREMES AND MARSUPIALS

1. 2. 3. 4. 5. 6.

7. 8. 9. 10. 11. 12. 13. 14. 15. 16.

17.

B C A It uses its flat, rubbery bill to search for food. mammal that carries and nourishes its young in a pouch Marsupials give birth to live young very early in their development. The young continue to grow in their mother's pouch. opossum It uses small front limbs to pull itself through the mother's fur to the pouch. marsupial marsupial monotreme marsupial marsupial marsupial monotreme the introduction of foreign predators into the environment; habitat destruction It was hunted by people who thought it was a threat to their livestock.

SECTION: CHARACTERISTICS OF MAMMALS

1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14. 15. 16. 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14. 15.

A C C mammary protein C A D blubber fur molars incisors canines A D B B D C A C A B C B D B C A D B

SECTION: PLACENTAL MAMMALS

Directed Reading B

SECTION: CHARACTERISTICS OF BIRDS

1. 2. 3. 4. 5. 6. 7. 8. 9. 10.

C A preening molting contour feathers down feathers B B A C

Copyright © by Holt, Rinehart and Winston. All rights reserved.

Holt Science and Technology

96

Birds and Mammals

Back

Print TEACHER RESOURCE PAGE

Answer Key

Directed Reading A

SECTION: EVERYTHING IS CONNECTED

1. D 2. Answers will vary. Sample answer: 14. 15. 16. 17. 18. 13. Answers will vary. Sample answer:

3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14. 15. 16. 17.

18.

19. 20.

Ecology is the study of interactions of living organisms and their environment. all organisms that live together and interact with one another nonliving factors, like water, soil, and light biotic biotic abiotic abiotic biotic abiotic 2 5 1 4 3 population Answers will include four of the following: gull, sparrow, snail, algae, egret, cordgrass, heron, jellyfish, shrimp, sea croaker, turtle Answers will include three of the following: eating, building nests, eating the algae growing on it, hiding in it abiotic biosphere

19. 20.

21.

22. 23.

fungi, bacteria, or other organisms that break down food food chain web toward the one doing the eating land and aquatic Answers will vary. Sample answer: The grass uses most of the energy for its life processes and only stores some of the energy. energy pyramid There were a lot of elk, since the wolves didn't eat them, and they overgrazed grass, so it was almost gone. Answers will vary. Sample answer: They think that returning the wolves will restore the natural energy flow, bring populations back into balance, and help the environment stay healthy. Wolves sometimes eat cows and sheep. Answers will vary. Sample answer: Elk: number reduced. Plants: more grow. Snowshoe hares and foxes: increased number.

SECTION: TYPES OF INTERACTIONS

1. B 2. Answers will vary. Sample answer: The

3. 4.

SECTION: LIVING THINGS NEED ENERGY

B producers, consumers, decomposers producers photosynthesis consumers herbivore carnivore omnivore Answers may vary. Sample answer: grasshopper, prairie dog, bison 10. grasshopper mouse 11. scavengers 12. decomposers

1. 2. 3. 4. 5. 6. 7. 8. 9.

5. 6.

7. 8. 9.

10. 11.

population remains about the same because most offspring do not survive. limiting factor Answers will vary. Sample answer: if population gets too large for the amount of food that is available carrying capacity Answers will vary. Sample answer: Some sort of limiting factor will cause the population to fall again. predators competition Answers will vary. Sample answer: Elk in Yellowstone compete for food; different species of trees compete for sunlight. A D

Copyright © by Holt, Rinehart and Winston. All rights reserved.

Holt Science and Technology

87

Interactions of Living Things

Back

Print TEACHER RESOURCE PAGE

12. Answers will vary. Sample answer:

13.

14.

15.

16. 17. 18. 19. 20. 21. 22. 23. 24.

25.

A cheetah runs very quickly to catch its prey; a goldenrod spider blends in with a flower to catch its prey when the prey lands on the flower. Answers will vary. Sample answer: Two of the following: run away, stay in groups, camouflage, use poison, use warning coloration Answers will vary. Sample answer: Two of the following: bombardier beetle and skunk spray irritating chemicals; bees, ants, and wasps inject acid; dart-poison frog and the hooded pitohui contain toxin It can serve as a warning that this type of animal is poisonous or causes some other kind of harm. A mutualism, commensalism, parasitism mutualism commensalism parasitism parasite host no; they would have to find new hosts Answers will vary. Sample answer: This is called coevolution. The ant and the acacia tree have evolved so that the tree provides food for the ant and the ant attacks all other insects that come to the tree. Answers will vary. Sample answer: Some bats have evolved long thin noses so that they can better get nectar and pollinate the flowers.

3. 4. 5. 6. 7. 8. 9. 10.

producers photosynthesis algae A C D B C

13. 14. 15. 16. 17. 18. 19.

B B C C C B B

SECTION: TYPES OF INTERACTIONS

1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14. 15. 16. 17.

A A B D B B B C prey predator B C A A C B B

18. 19. 20. 21. 22. 23. 24. 25. 26. 27. 28. 29. 30. 31. 32. 33.

C D B C A B D A symbiosis host parasite C B D A A

Vocabulary and Section Summary

SECTION: EVERYTHING IS CONNECTED

1. ecology: the study of the interaction of

Directed Reading B

SECTION: EVERYTHING IS CONNECTED

1. 2. 3. 4. 5. 6. 7.

B biotic abiotic individual population community ecosystem

8. 9. 10. 11. 12. 13. 14.

C C C B B C A

living organisms with one another and with their environment 2. biotic: describes living factors in the environment 3. abiotic: describes the nonliving part of the environment, including water, rocks, light, and temperature 4. population: a group of organisms of the same species that live in a specific geographical area

SECTION: LIVING THINGS NEED ENERGY

1. D 2. B 11. A 12. D

Copyright © by Holt, Rinehart and Winston. All rights reserved.

Holt Science and Technology

88

Interactions of Living Things

Back

Print TEACHER RESOURCE PAGE

Answer Key

Directed Reading A

SECTION: THE CYCLES OF MATTER

1. 2. 3. 4. 5. 6. 7. 8. 12. D 13. a slow-growing species that is well-

adapted to an area over time

14. Answers will vary. Sample answer:

9. 10. 11. 12. 13.

14.

15. 16. 17. 18. 19. 20. 21. 22. 23.

water cycle evaporation condensation precipitation runoff groundwater transpiration It helps transport nutrients; it helps transport wastes; it helps regulate temperature. C D C Plants use it to make sugars. Answers will vary. Sample answer: During decombustion, fungi and bacteria break down organic matter. Combustion: a substance burns. Answers will vary. Sample answer: During combustion, a substance burns. nitrogen cycle nitrogen fixation to build proteins and DNA for new cells Decomposition and lightning performnitrogen fixation. Plant roots take up nitrogen from the soil. by eating plants or organisms that eat plants Nitrogen is released into the soil. D calcium, phosphorous

Biodiversity makes a community better able to survive disturbances such as insects and disease.

Directed Reading B

SECTION: THE CYCLES OF MATTER

1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14. 15. 16. 17.

C C D A B runoff groundwater B C C A decomposition combustion C C B B

SECTION: ECOLOGICAL SUCCESSION

1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11.

SECTION: ECOLOGICAL SUCCESSION

1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11.

Most were dead but still standing. B D pioneer species lichens insects no soil, and usually just bare rock hundreds or thousands of years B C B

D B B D D A D B D D C

Vocabulary and Section Summary

SECTION: THE CYCLES OF MATTER

1. evaporation: the change of a substance

from a liquid to a gas

2. condensation: the change of state from

a gas to a liquid

Copyright © by Holt, Rinehart and Winston. All rights reserved.

Holt Science and Technology

68

Cycles in Nature

Back

Print TEACHER RESOURCE PAGE

Answer Key

Directed Reading A

SECTION: LAND BIOMES

1. 2. 3. 4. 5. 6. 7.

SECTION: MARINE ECOSYSTEMS

1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12.

8.

9. 10.

11. 12. 13. 14. 15. 16. 17. 18.

19. 20. 21. 22. 23. 24. 25. 26. 27.

abiotic biotic biome temperate deciduous forests, coniferous forests, tropical rain forests to save water during the winter coniferous most produce seeds in cones; have leaves that are like needles with thick, waxy coating helps keep coniferous leaves from drying out; protects needles from damage by cold winter temperatures; allows conifers to keep leaves all year covered with thick layer of needles; little light reaches the ground because they have more kinds of plants and animals than any other land biome. in the canopy in plants C B B C C Desert plants grow far apart to avoid competition for water; have shallow, widespread roots to take up water after a storm; have fleshy stems and leaves to store water; and have a waxy coating to prevent water loss. C D A B tundra permafrost The layer of thawed soil is too shallow for deep-rooted plants. It is located at the top of tall mountains. an area on a mountain above a certain elevation where trees cannot grow.

13. 14.

15.

16. 17. 18. 19.

marine ecosystems blue whales plankton They use photosynthesis to make their own food. A C D B C D A Through evaporation, oceans provide much of Earth's precipitation; ocean temperatures and currents affect world climates and wind patterns; and people and animals depend on oceans for food. mudflats, sandy beaches, rocky shores Some have rootlike structures called holdfasts to attach themselves to rocks; others release a special glue that attaches them to rocks. Answers will vary. Sample answers: algae, brightly colored fishes, sponges, sea stars, sea urchins estuary plankton Most of the animals in the Sargasso Sea are the same color as sargassum. Yes, because the icy waters are rich in nutrients that support plankton, which in turn support larger animals.

SECTION: FRESHWATER ECOSYSTEMS

1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11.

melting ice or snow and a spring river tributary how quickly water moves C A B B A C Sunlight reaches the bottom of the littoral zone.

Copyright © by Holt, Rinehart and Winston. All rights reserved.

Holt Science and Technology

89

The Earth's Ecosystems

Back

Print TEACHER RESOURCE PAGE

12. Answers will vary. Sample answers:

13. 14. 15. 16.

17. 18. 19. 20.

catfish; carp; worms; crustaceans; fungi; bacteria C A B Wetlands support many different kinds of plants and animals; they play a role in flood control by soaking up large amounts of water; they help replenish underground water supplies. in shallow areas along shores of lakes, ponds, rivers, and streams in low-lying areas and beside slowmoving rivers C B

Vocabulary and Section Summary

SECTION: LAND BIOMES

1. biome: a large region characterized by

Directed Reading B

SECTION: LAND BIOMES

1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11.

a specific type of climate and certain types of plant and animal communities 2. savanna: a grassland that often has scattered trees and that is found in tropical and subtropical areas where seasonal rains, fires, and drought happen 3. desert: a region that has little or no plant life, long periods without rain, and extreme temperatures; usually found in hot climates 4. tundra: a treeless plain found in the Arctic, in the Antarctic, or on the tops of mountains that is characterized by very low winter temperatures and short, cool summers

biotic biome abiotic B C A D C C A C

12. 13. 14. 15. 16. 17. 18. 19. 20. 21.

B B A C D A B C B C

SECTION: MARINE ECOSYSTEMS

1. plankton: the mass of mostly

microscopic organisms that float or drift freely in freshwater and marine environments 2. estuary: an area where fresh water from rivers mixes with salt water from the ocean

SECTION: FRESHWATER ECOSYSTEMS

1. littoral zone: the shallow zone of a

SECTION: MARINE ECOSYSTEMS

1. 2. 3. 4. 5. 6. 7. 8.

C B B C C B D D

9. 10. 11. 12. 13. 14. 15.

B B B B A B D

2.

3.

SECTION: FRESHWATER ECOSYSTEMS

1. 2. 3. 4. 5. 6. 7. 8.

4.

B D C A B A D B

9. 10. 11. 12. 13. 14. 15.

B C D C B D A

5. 6.

lake or pond where light reaches the bottom and nurtures plants open-water zone: the zone of a pond or lake that extends from the littoral zone and that is only as deep as light can reach. deep-water zone: the zone of a lake or pond below the open-water zone, where no light reaches wetland: an area of land that is periodically underwater or whose soil contains a great deal of moisture marsh: a treeless wetland ecosystem where plants such as grasses grow swamp: a wetland ecosystem in which shrubs and trees grow

Copyright © by Holt, Rinehart and Winston. All rights reserved.

Holt Science and Technology

90

The Earth's Ecosystems

Back

Print TEACHER RESOURCE PAGE

Answer Key

Directed Reading A

SECTION: ENVIRONMENTAL PROBLEMS

1. The Industrial Revolution began in the 23. habitat 24. biodiversity 25. When habitats are damaged or

destroyed, biodiversity is lost.

26. deforestation 27. Answers will vary. Sample answer:

2. 3. 4. 5. 6. 7. 8.

9.

10. 11. 12.

13.

14.

15. 16. 17. 18. 19.

20.

21. 22.

late 1700s. People started relying more and more on machines, which released harmful substances into the air, water, and soil. C B D B C C Chemicals can be used to treat diseases. Some are used in plastics and preserved foods. Answers will vary. Sample answer: Two groups of harmful chemicals are CFCs and PCBs. CFCs destroy ozone, the protective layer around the Earth that shields us from harmful ultraviolet light. PCBs are poisonous and may cause cancer. radioactive wastes carbon dioxide Many scientists think the increase in atmospheric carbon dioxide has increased global temperatures. The rise in global temperatures could cause polar icecaps to melt. This could raise the level of the world's oceans, causing floods in coastal areas. Noise pollution can affect a person's ability to hear and think clearly and can damage hearing. A B B C An exotic species is an organism that makes a home for itself in a new place. Without knowing it, people carry exotic species with them on boats, airplanes, and cars. C A

28. 29. 30.

31. 32. 33.

Without the trees, the soils of the tropical rain forest may be damaged. There will be a loss of biodiversity. point-source nonpoint-source Animals may mistake plastics for food, or they may become tangled in plastics. Drinking polluted water may make people sick. Breathing polluted air harms people with respiratory problems. Some chemicals may cause cancers many years after a person is exposed to the chemicals.

SECTION: ENVIRONMENTAL SOLUTIONS

1. food, healthcare, transportation, and

waste disposal C A C D packaging material biodegradable Answers will vary. Sample answer: by using mulch, compost, manure, and natural pest controls instead of chemical fertilizers and pesticides 9. Answers will vary. Sample answer: New energy-producing sources being studied include the sun, wind, tides, and falling water. 10. Answers will vary. Sample answer: Car companies have developed electric and hydrogen-fueled automobiles. 11. Answers will vary. Sample answer: Plastic bags can be made into park benches.

2. 3. 4. 5. 6. 7. 8.

Copyright © by Holt, Rinehart and Winston. All rights reserved.

Holt Science and Technology

78

Environmental Problems and Solutions

Back

Print TEACHER RESOURCE PAGE

12. Answers will vary. Sample answer: Old 28. Answers will vary. Sample answer: vol-

13.

14. 15. 16. 17. 18.

19.

20.

21.

22.

23.

24. 25.

26.

27.

tires can be reused for playground surfaces and to make walls for new homes. Plants and filter-feeding animals, such as clams, are used to clean the water. The water isn't pure enough to drink, but it can be used to water golf courses, lawns, and crops. Sometimes, the reclaimed water is returned to underground water supplies. D C A A Answers will vary. Sample answer: Plastics, glass, and wood can be recycled. Old glass can be made into new bottles and jars. Some communities have recycling centers or they collect materials from the curb where people place them. Some people worry that waste-toenergy plants pollute the air or that the plants reduce recycling. Biodiversity is important to an ecosystem because every species has a unique role in the ecosystem. If an important predator in an ecosystem is lost, then the number of prey will increase. The prey might eat plants, keeping other animals from getting food. Eventually, even the prey will run out of food. The Endangered Species Act forbids activities that would harm a species on the endangered species list. California condor Each organism is part of an interconnected web. To protect these organisms, the entire web must be protected. To do so, complete habitats must be preserved. The EPA works to help people have a clean environment, keeps people informed about environmental issues, and enforces environmental laws. reduce pollution, reduce pesticide use, protect habitats, enforce the Endangered Species Act, develop alternative energy sources

unteer at a local preserve or nature center; give away old toys; use recycled paper; wear hand-me-downs; recycle glass, plastics, paper, aluminum, and batteries

Directed Reading B

SECTION: ENVIRONMENTAL PROBLEMS

1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 21. 22. 23. 24. 25. 26. 27. 28.

A C B C A D B B B C habitat biodiversity C A B A D B

11. 12. 13. 14. 15. 16. 17. 18. 19. 20.

A B B A C B A C B C

SECTION: ENVIRONMENTAL SOLUTIONS

1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13.

C C D C A C C B A B A C C

14. 15. 16. 17. 18. 19. 20. 21. 22. 23. 24. 25. 26.

A A C D C D A C B D D A C

Copyright © by Holt, Rinehart and Winston. All rights reserved.

Holt Science and Technology

79

Environmental Problems and Solutions

Back

Print TEACHER RESOURCE PAGE

Answer Key

Directed Reading A

SECTION: BODY ORGANIZATION

1. 2. 3. 4. 10. 11. 12. 13.

5.

6. 7. 8. 9. 10. 11. 12. 13. 14. 15. 16. 17. 18. 19. 20. 21. 22. 23. 24. 25. 26. 27.

homeostasis C C If homeostasis is disrupted, cells may not get the materials they need. So, they may be damaged or die. Your body is like a soccer team because each cell in your body has a job in maintaining homeostasis. tissue D C A B Nervous tissue sends out signals to your brain when the stomach is full. connective tissue epithelial tissue organ systems D F L A G C K E J B H I The cardiovascular and circulatory systems work very closely together to deliver the materials cells need to survive.

14. 15. 16. 17. 18. 19. 20. 21.

22. 23.

compact bone compact bone spongy bone Red marrow produces both red and white blood cells. Yellow marrow, found in the central cavity of long bones, stores fat. In children, red marrow fills the center of long bones. Red marrow is replaced with yellow marrow as children become adults. C F E G D B A Bones may be fractured. Bones in joints may be dislocated. A sprain may happen if a ligament is stretched too far or torn. osteoporosis arthritis

SECTION: THE MUSCULAR SYSTEM

1. It is impossible to sit still and never

2. 3. 4. 5. 6. 7.

SECTION: THE SKELETAL SYSTEM

1. 2. 3. 4. 5. 6. 7. 8. 9.

bone, cartilage, connective tissue B D protection, storage, movement, and blood cell formation ribs, vertebrae, skull minerals or fat marrow osteoblasts spongy bone

8. 9. 10. 11. 12. 13.

move any muscles at all because somewhere in your body, muscles are always working. B C A voluntary involuntary When you want to move, signals travel from your brain to your skeletal muscle cells. The muscle cells then contract, or get shorter. skeletal muscles, bones flexor extensor biceps triceps Strong muscles can help organs. Contracting muscles squeeze blood vessels and increase blood flow without requiring the heart to work more. More endurance also lets muscles work longer without getting tired.

Copyright © by Holt, Rinehart and Winston. All rights reserved.

Holt Science and Technology

90

Body Organization and Structure

Back

Print TEACHER RESOURCE PAGE

14. resistance exercises 15. weight 16. Answers will vary. Sample answer: 27. A blood clot forms over a cut to stop

17. 18. 19. 20. 21.

Jogging, cycling, skating, swimming, and walking are examples of aerobic exercise. aerobic exercises A B D Anabolic steroids can damage the heart, liver, and kidneys. They can cause high blood pressure. They can cause bones to stop growing if they are taken before the skeleton is mature.

bleeding and keep bacteria from entering the wound. Bacteria-fighting cells then come to the area to kill bacteria. Damaged cells are replaced through cell division. Eventually, all that is left on the surface is a scar.

Directed Reading B

SECTION: BODY ORGANIZATION

1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14. 15. 16. 17. 18. 19. 20. 21. 22. 23. 24. 25.

SECTION: THE INTEGUMENTARY SYSTEM

1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14. 15. 16. 17. 18. 19. 20. 21. 22. 23. 24.

25. 26.

C skin, hair, nails water, foreign particles nerve endings sweat glands wastes melanin Melanin absorbs ultraviolet light from the sun. D E C D A B F epidermis dermis epithelial keratin collagen D A melanin Hair helps protect skin from ultraviolet light. Hair keeps particles out of your eyes and nose. Hair helps regulate body temperature in most mammals. nail root Damage to the genetic material in the skin cells can cause cancer. Acne can develop if excess oil combines with dead skin cells and bacteria to clog hair follicles.

A C B D C A B organ muscle tissue nervous tissue epithelial tissue organ system B A D B C C A B D B D A C

SECTION: THE SKELETAL SYSTEM

1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14. 15. 16.

cartilage movement ribs minerals marrow B D A B blood vessels compact bone spongy bone C B C A

Copyright © by Holt, Rinehart and Winston. All rights reserved.

Holt Science and Technology

91

Body Organization and Structure

Back

Print TEACHER RESOURCE PAGE

Answer Key

Directed Reading A

SECTION: THE CARDIOVASCULAR SYSTEM

1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14. 15. 16. 17. 18. 19. 20. 21. 22. 23. 24. 25. 26. 27. 28. 29. 30. 31. 32. 33. 34. 7. destroy pathogens and help clean

circulatory system cardiovascular system heart blood vessel blood vessels B A B B A C to prevent blood from flowing backward the valves E D A B C a capillary veins arteries C D C pulmonary systemic body exercise heart diseases D F E C heart attack

wounds viruses antibodies white blood cells temperature enlarge B when the ventricles contract when the ventricles relax heart and kidney D B They react as if the antigens were pathogens. 20. O 21. lost blood

8. 9. 10. 11. 12. 13. 14. 15. 16. 17. 18. 19.

SECTION: THE LYMPHATIC SYSTEM

1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14. 15. 16.

SECTION: BLOOD

1. 5 2. red blood cells, white blood cells,

B pathogens lymph capillaries They are too large. lymph into the large neck veins A C A D B A C T cells spleen fighting infection; removing dead or damaged cells 17. produces, monitors, stores, and destroys 18. tonsils 19. infection

SECTION: THE RESPIRATORY SYSTEM

1. 2. 3. 4. 5. 6. 7.

platelets, plasma

3. plasma 4. carry oxygen and nutrients through

the body 5. oxygen you inhale 6. platelets

energy E A B F C D

Copyright © by Holt, Rinehart and Winston. All rights reserved.

Holt Science and Technology

94

Circulation and Respiration

Back

Print TEACHER RESOURCE PAGE

8. 9. 10. 11. 12. 13. 14. 15. 16. 17. 18. 19. 20. 21.

J K I H G diaphragm, rib muscles diaphragm rib muscles oxygen red blood cells energy carbon dioxide B B

Directed Reading B

SECTION: THE CARDIOVASCULAR SYSTEM

1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14. 15. 16. 17. 18. 19. 20. 21. 22. 23. 24.

10. 11. 12. 13. 14. 15. 16. 17. 18. 19. 20. 21. 22. 23. 24. 25.

D A B A blood blood vessels temperature blood pressure systolic diastolic antigens antibodies type A type B C D

SECTION: THE LYMPHATIC SYSTEM

1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14. 15. 16. 17.

cardiovascular system blood heart blood vessels D A B D B B arteries capillaries veins pulse blood vessels B A B D D A C B C

A C lymph capillaries lymph lymphatic vessels bone marrow lymph nodes lymphocyte killer T cell C C A D B C B B

SECTION: THE RESPIRATORY SYSTEM

1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14. 15. 16.

SECTION: BLOOD

1. 2. 3. 4. 5. 6. 7. 8. 9.

A D C A C A A B B

A A C B B C A D B D A B diaphragm muscles oxygen energy

Copyright © by Holt, Rinehart and Winston. All rights reserved.

Holt Science and Technology

95

Circulation and Respiration

Back

Print TEACHER RESOURCE PAGE

Answer Key

Directed Reading A

SECTION: THE DIGESTIVE SYSTEM

1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 34. It is stored in the rectum until it is

expelled through the anus.

11. 12. 13. 14. 15. 16. 17. 18. 19.

20. 21. 22. 23. 24. 25. 26. 27. 28. 29. 30.

31. 32. 33.

B D pancreas, liver, gallbladder A mechanical chemical carbohydrate enzymes amino acids When you chew your food, you break it into small, slippery pieces. These pieces are easier to swallow. They are also easier to digest. mashing shredding shredding grinding saliva simple sugars The tongue pushes it in. It squeezes food into the stomach. The stomach squeezes food with muscular contractions. This is mechanical digestion. The stomach also mixes the food with digestive juices. This is chemical digestion. acid and enzymes It is killed by stomach acid. chyme the small intestine pancreas hormones It is small in diameter. absorb nutrients A It stores bile. Bile breaks large fat droplets into small droplets so they can be digested more easily. liver B It is another name for a carbohydrate called cellulose, which is found in fruits and vegetables. Humans cannot digest fiber.

SECTION: THE URINARY SYSTEM

1. C 2. It removes waste products from the 3. 4. 5. 6. 7. 8. 9. 10.

11.

12. 13. 14.

blood. carbon dioxide and ammonia B A They clean, or filter, the blood. a harmful substance containing nitrogen B to keep water levels in balance, otherwise your body would swell up When you're thirsty, ADH keeps your body from losing more water through urine. It signals the kidneys to take water from the nephrons and return it to the bloodstream. It causes the kidneys to make more urine. This decreases the amount of water in your blood. B through the urethra damage to nephrons can prevent normal kidney functioning and can lead to kidney disease

Directed Reading B

SECTION: THE DIGESTIVE SYSTEM

1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14. 15. 16. 17.

B C D A mechanical chemical amino acids enzymes C A C B saliva tongue esophagus stomach enzymes

Copyright © by Holt, Rinehart and Winston. All rights reserved.

Holt Science and Technology

75

The Digestive and Urinary Systems

Back

Print TEACHER RESOURCE PAGE

Answer Key

Directed Reading A

SECTION: THE NERVOUS SYSTEM

1. the brain and spinal cord. 2. all parts of the nervous system except 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14. 15. 16. 17. 18. 19. 20. 21. 22. 23. 24. 25. 26. 27. 28. 29. 30. 31. 32. 33. 34. 35. 36. 37. 38. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14. 15. 16. 17.

brain and spinal cord P C C P neurons impulses B C A axon terminal receptors motor neurons A sensory; motor D motor S A A S A the brain I V I cerebrum, cerebellum, medulla (any order) cerebrum left the cerebellum medulla vertebrae neurons; axons peripheral brain may block all information to and from the brain wear a seat belt; use safety equipment

18. 19. 20. 21. 22. 23. 24. 25. 26. 27. 28. 29. 30. 31. 32.

light temperature protect the body from damage reflex feedback mechanism most of the time C F B D A G E C iris The lens becomes more curved for close focus, and less curved to focus on objects far away. nearsightedness convex sound 3 4 1 5 2 cochlea B C A bitterness olfactory cells nose

SECTION: THE ENDOCRINE SYSTEM

1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14.

SECTION: RESPONDING TO THE ENVIRONMENT

1. Sensory receptors in your shoulders

send impulses to your brain.

B A C epinephrine (or adrenaline) metabolism killer T cells H A F C E B G D

Copyright © by Holt, Rinehart and Winston. All rights reserved.

Holt Science and Technology

82

Communication and Control

Back

Print TEACHER RESOURCE PAGE

15. 16. 17. 18. 19. 20. 21. 22. 23.

by feedback mechanisms feedback 1 4 2 5 3 diabetes mellitus A person with diabetes may need daily injections of insulin to keep his or her blood glucose level within safe limits. 24. The child's growth is stunted. 25. growth hormone

9. 10. 11. 12. 13. 14. 15. 16. 17. 18. 19. 26. 27. 28.

A iris lens retina optic nerve A B B A B C olfactory taste molecules

20. 21. 22. 23. 24. 25.

B A A B A C

Directed Reading B

SECTION: THE NERVOUS SYSTEM

1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 18. 19. 20. 21. 22. 23. 24. 25. 26. 27. 28. 29. 30. 31.

SECTION: THE ENDOCRINE SYSTEM

1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14. 15. 16. 17. 18. 19. 20. 21. 22.

B central command post information responds central peripheral C 13. C A 14. A B 15. B C 16. D A 17. C B somatic voluntary autonomic homeostasis brain involuntary voluntary C cerebrum hemisphere C D D C

B endocrine gland hormones bloodstream epinephrine B A A C D B feedback glands hormones B C A D C A B

Vocabulary and Section Summary

SECTION: THE NERVOUS SYSTEM

1. central nervous system (CNS): the

SECTION: RESPONDING TO THE ENVIRONMENT

1. 2. 3. 4. 5. 6. 7. 8.

brain and spinal cord

2. peripheral nervous system (PNS): all of

C A D D C receptors brain feedback mechanism

the parts of the nervous system except for the brain and the spinal cord 3. neuron: a nerve cell that is specialized to receive and conduct electrical impulses

Copyright © by Holt, Rinehart and Winston. All rights reserved.

Holt Science and Technology

83

Communication and Control

Back

Print TEACHER RESOURCE PAGE

Answer Key

Directed Reading

SECTION: ANIMAL REPRODUCTION

1. All living things must reproduce so 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14. 15. 16. 17. 18. 19. 20. 21. 22. 23. 24. 25. 17. 18. 19. 20. 21. 22. 23. 24. 25. 26. 27. 28.

that their species will survive. asexual genetically budding fragmentation regeneration A B C C A C A D B A B C A placental mammal monotreme marsupial monotreme marsupial placental mammal

identical twins one-third fraternal twins quintuplets C D C B A B C A

SECTION: GROWTH AND DEVELOPMENT

C B D A A D B A B E C D C D A D puberty Sample answers: His body becomes more muscular; his voice becomes deeper; body and facial hair appear. 19. Sample answers: The amount of fat in the hips and thighs increase; the breasts enlarge; body hair appears, menstruation begins. 20. Sample answers: Muscles lose their flexibility; eyesight deteriorates; body fat increases; and there is some hair loss. 21. Sample answers: Hair may turn gray; athletic abilities decline; and skin may wrinkle.

1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14. 15. 16. 17. 18.

SECTION: HUMAN REPRODUCTION

1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13.

A F D E C B G D B A C C A woman begins menstruating at puberty. A woman stops menstruating in her late 40s or early 50s. 14. blood and tissue 15. ovulation 16. 28 days

Copyright © by Holt, Rinehart and Winston. All rights reserved.

Holt Science and Technology

83

Reproduction and Development

Back

Print TEACHER RESOURCE PAGE

Answer Key

Directed Reading A

SECTION: DISEASE

1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14. 15. 16. 17. 18. 19. 20. 21. 22. 23. 24. 25. 26. 27. 28. 29. 30. 7. 8. 9. 10. 11. 12. 13. 14. 15. 16. 17. 18. 19. 20. 21. 22.

31. 32. 33. 34.

disease noninfectious B D E A C infectious pathogens D E D B A C microorganisms bacteria cooked salmonella refrigerator clean C B A C A They had more resistance to smallpox. immunity vaccine pathogens that have been killed or specially treated so that people can't become very sick antibiotics kill them, slow their growth Viruses are not alive and antibiotics kill only living things. by locating and destroying the cells the viruses have invaded

23. 24.

25.

26. 27. 28. 29. 30. 31. 32. 33. 34. 35. 36.

SECTION: YOUR BODY'S DEFENSES

1. 2. 3. 4. 5. 6.

pathogens D C A cut platelets

immune system pathogens macrophages, T cells, and B cells E B A D C F microphages replicate viral antigens a T cell response and a B cell response infected cells cells that can create antibodies Antibodies bind with viral antigens on viruses, forcing them to clump together. This marks the virus particles for destruction. fever A mild fever slows the growth of some pathogens and helps immune cells reproduce. B cells must have had contact with a pathogen before they can make the correct antibodies. This can take 2 weeks which is too long to prevent infection. memory B cell C A B D pollen autoimmune disease disrupt the normal activities of the organs they have invaded killer T cells AIDS (Acquired Immune Deficiency Syndrome) People with AIDS do not have enough helper T cells, so nothing activates B cells or killer T cells. Therefore the immune system cannot attack pathogens.

Copyright © by Holt, Rinehart and Winston. All rights reserved.

Holt Science and Technology

76

Body Defenses and Disease

Back

Print TEACHER RESOURCE PAGE

Answer Key

Directed Reading A

SECTION: GOOD NUTRITION

1. D 2. carbohydrates, fats, proteins, 40. the amount of each nutrient in one 41. 42. 43. 44. 45. 46.

water,vitamins, and minerals

3. Calories 4. carbohydrates 5. simple carbohydrates and complex 6. 7. 8. 9. 10. 11. 12. 13. 14. 15. 16. 17. 18. 19. 20. 21.

22. 23. 24. 25. 26. 27. 28. 29. 30. 31. 32. 33. 34. 35. 36. 37. 38. 39.

carbohydrates simple carbohydrates complex carbohydrates starches whole-grain foods, fruits, and vegetables proteins amino acids complete proteins incomplete proteins fats saturated fats and unsaturated fats Saturated fats raise blood cholesterol levels. heart disease Unsaturated fats lower blood cholesterol levels. vegetable oil and fish water transporting substances, regulating body temperature, and providing lubrication 8 minerals calcium, chloride, magnesium, phosphorus, potassium, and sodium 12 potassium iron vitamins E C B A D A B C A D C

serving of the food B A D C B weak bones, low blood pressure, and heart problems 47. exercise and healthy food choices

SECTION: RISKS OF ALCOHOL AND OTHER DRUGS

1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14.

15. 16. 17. 18. 19. 20.

21. 22. 23. 24. 25.

drug D C B E A tolerance physical dependence withdrawal symptoms addiction psychological dependence chemicals chamomile The FDA does not regulate herbal medicines and cannot guarantee their safety. over-the-counter drugs prescription a description of the drug, directions for use, and the amount to be taken side effect on the label Answers will vary. Sample answer: Never take another person's medicine; read the label before each use, and always follow the instructions and those provided by your doctor or pharmacist; do not take more or less medication than prescribed; consult a doctor if you have side effects; and throw away leftover and out-of-date medicines. nicotine lung cancer more than 430,000 throat F

Copyright © by Holt, Rinehart and Winston. All rights reserved.

Holt Science and Technology

93

Staying Healthy

Back

Print TEACHER RESOURCE PAGE

26. 27. 28. 29. 30. 31.

32. 33. 34. 35. 36.

37. 38. 39. 40. 41. 42. 43.

A C D E B Answers will vary. Sample answer: Alcohol slows the central nervous system, may cause memory loss, may cause damage to organs, may affect decision-making, and may lead to unhealthy risk-taking. designer drug brain damage C to prevent or improve a medical condition Answers will vary. Sample answer: A drug abuser may take drugs for the temporary good feelings they produce, to escape from problems, or to belong to a group. gateway drugs peer pressure Many people do not recognize the dangers of drugs because of misinformation. psychological admit to abusing drugs and decide to stop withdrawal symptoms are painful and cravings may remain for years drug treatment center

13. 14. 15. 16. 17. 18.

19.

20. 21. 22. 23. 24. 25. 26. 27. 28. 29. 30.

SECTION: HEALTHY HABITS

1. 2. 3. 4. 5. 6. 7.

8. 9.

10. 11. 12.

B B skin, hair, and teeth vertical line by pulling your chair forward and planting your feet firmly on the ground aerobic exercise Answers will vary. Sample answer: basketball, walking, biking, running, and swimming oxygen Answers will vary. Sample answer: Aerobic exercise strengthens the heart, lungs, and bones; conserves nutrients; burns calories; aids digestion; gives people more energy; and protects physical and mental health. sleep 9.5 hours the deepest, most restful period of sleep

31. 32. 33.

A C B B accidents Answers will vary. Sample answer: never hike or camp alone, dress for the weather and the activity, tell someone where you are going and when you will return, and purify any water you may find and drink in the wilderness Answers will vary. Sample answer: never swim alone; learn how to swim; do not dive into shallow or unknown water; and if a storm threatens, seek shelter water smoke detectors stairs flames walkways seat belt helmet safety equipment instructions 911 You should be able to describe the accident, the number of people injured, and the type of injuries. first-aid CPR You need to be trained before attempting any lifesaving procedures.

Directed Reading B

SECTION: GOOD NUTRITION

1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14. 15.

A C D B A B A B A C A D A B C

16. 17. 18. 19. 20. 21. 22. 23. 24. 25. 26. 27. 28. 29. 30.

B A C D A B C A D A C A D C B

Copyright © by Holt, Rinehart and Winston. All rights reserved.

Holt Science and Technology

94

Staying Healthy

Information

HST_CRF_04_02_03.qxd

302 pages

Report File (DMCA)

Our content is added by our users. We aim to remove reported files within 1 working day. Please use this link to notify us:

Report this file as copyright or inappropriate

119511

You might also be interested in

BETA
HST_CRF_04_02_03.qxd
C200_QR_Program_Overview-R
LS_ReadingComp07_1of2.qxd
Automated Conversion of English and Hindi Text to Braille Representation
HST_CRF_04_02_03.qxd