Read What_is_life.pdf text version

What Is Life? ­ Scavenger Hunt Authors: Joy Perry, Dave Burbach, Lynn Hudock


Students participate in a field scavenger hunt to collect a variety of specimens, sort living from nonliving, then classify and create a dichotomous key for the collection. This activity is designed to introduce students to the shared features of living organisms, systematics, and biodiversity.

Grade Range

Middle School/High School

Teaching/Learning Objective(s)

Students will: ß Distinguish between living and nonliving specimens by considering features that define life. ß Classify and organize specimens based upon observable traits. ß Construct and use a dichotomous key from collected field samples.

Time Required

3 (50-minute) classes

Materials and Preparation Procedures

ß ß ß Dissecting microscope and/or magnifying lenses Forceps Collection jars, paper bags, bucket ß Trowel


Teacher Background A dichotomous key is a biological tool that allows the user to determine the identity of an unknown item from a list of items. "Dichotomous" means "divided into two parts". A dichotomous key gives two choices in each step to direct the user to the correct name of the specimen. The Student Handout includes a description of the activity and related discussion questions. There may be many correct dichotomous keys for the same list of specimens. There is no wrong key as long as all specimens are accounted for correctly and can be identified. Examples of a dichotomous key in written and graphical form for a specific list of items are provided in the Dichotomous Key handout.


Posted August 2003

General precautions: Avoid collecting higher level organisms. Be aware of poisonous plants and other hazards on your site. Warn students against collecting venomous arthropods or touching sharp objects. Query students about known bee/wasp sting allergies before going into the field.

Student Assessment

Activity Checklist Criteria Score ­ Possible Points 1. Were 10 specimens used in the key? (5) 2. Was the key constructed with 2 choices in each step? (5) 3. Does the key work for all specimens? (5) 4. Are the characteristics appropriate? (4) 5. Were living and nonliving specimens distinguished correctly? (4) 6. Correct grammar/spelling. (2) TOTAL= 25

Wisconsin Science Standards

A: SCIENCE CONNECTIONS: Students will understand that there are unifying themes: systems, order, organization, and interactions; evidence, models, and explanations; consistency, change, and measurement; evolution, equilibrium, and energy; and form and function among scientific disciplines. Those themes are to be used to connect the science content standards for Wisconsin to each other. A.12.3 Give examples that show how partial systems, models and explanations are used to give quick and reasonable solutions that are accurate enough for basic needs. A.12.4 Construct arguments that show how conflicting models and explanations of events can start with similar evidence. A.12.6 Identify and, using evidence learned or discovered, replace inaccurate personal models and explanations for science-related events. B. NATURE OF SCIENCE: Students will understand that science is ongoing and inventive, and that scientific understandings have changed over time as new evidence is found. B.12.3 Relate the major themes of science to human progress in understanding science and the world. B.12.5 Explain how science is based on assumptions about the natural world and themes that describe the natural world.


Posted August 2003

C. SCIENCE INQUIRY: Students will investigate questions using scientific methods and tools, revise their personal understanding to accommodate knowledge and communicate these understandings to others. C.12.1 When studying science content, ask questions suggested by current social issues, scientific literature, and observations of phenomena, build hypotheses that might answer some of these questions, design possible investigations, and describe results that might emerge from such investigations. C.12.3 Evaluate the data being collected during an investigation, critique the datacollection procedures and results, and suggest ways to make any needed improvements. F. LIFE AND ENVIRONMENTAL SCIENCE: Students will demonstrate an understanding of the characteristics and structures of living things, the processes of life, and how living things interact with each other and their environment. F.12.5 Understand the theory of evolution, natural selection, and biological classification.

Additional Materials

· · Student Handout Dichotomous Key Examples


Posted August 2003


3 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