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GCSE Biology Specimen Assessment Materials

For first teaching from September 2011 For first assessment from Summer 2012 For first award in Summer 2013 Subject Code: 1010

Foreword

The awarding bodies have prepared new specifications to comply with revised GCSE and subject criteria. The specimen assessment materials accompanying new specifications are provided to give centres guidance on the structure and character of the planned assessments in advance of the first assessment. It is intended that the specimen assessment materials contained in this booklet will help teachers and students to understand, as fully as possible, the markers' expectations of candidates' responses to the types of tasks and questions set at GCSE level. These specimen assessment materials should be used in conjunction with CCEA's GCSE Biology specification.

BLANK PAGE

GCSE Biology Specimen Assessment Materials

Contents

Specimen Papers Unit B1: Unit B1: Unit B2: Unit B2: Foundation Tier Higher Tier Foundation Tier Higher Tier 1 3 25 49 73 101 103 105 113 123 131 141 143 147 155 163

Mark Schemes General Marking Instructions Unit B1: Foundation Tier Unit B1: Higher Tier Unit B2: Foundation Tier Unit B2: Higher Tier Controlled Assessment Controlled Assessment Task and Guidance Notes for Teachers Controlled Assessment Task: Candidate Response Booklet A Controlled Assessment Task: Candidate Response Booklet B Controlled Assessment Mark Scheme

Subject Code QAN

1010 600/1164/6

A CCEA Publication © 2011

You may download further copies of this publication from www.ccea.org.uk

SPECIMEN PAPERS

1

2

Centre Number 71

Candidate Number

General Certificate of Secondary Education 2012

Science: Biology Unit B1 Foundation Tier

[CODE] SPECIMEN PAPER

TIME 1 hour 15 minutes INSTRUCTIONS TO CANDIDATES Write your Centre Number and Candidate Number in the spaces provided at the top of this page. Write your answers in the spaces provided in this question paper. Answer all questions. INFORMATION FOR CANDIDATES The total mark for this paper is 80. Figures in brackets printed down the right-hand side of pages indicate the marks awarded to each question or part question. Quality of written communication will be assessed in questions 3, 5(a) and 11.

For Examiner's use only Question Marks Number

1 2 3 4 5 6 7 8 9 10 11

Total Marks

3

Answer all questions 1 The key below shows a system of classification using five kingdoms.

(a)

Use the key to identify the kingdoms A, B, C and D. Kingdom A ________________ Kingdom B ________________ Kingdom C ________________ Kingdom D ________________ [4]

4

(b)

The smallest group that living organisms can be classified into is a species. What is a species? ________________________________________________________________ ________________________________________________________________ ________________________________________________________________ ________________________________________________________________ [2]

(c)

Explain why viruses are difficult to classify. ________________________________________________________________ ________________________________________________________________ ________________________________________________________________ ________________________________________________________________ [2]

5

2

The table below shows the number of organisms at each stage of a food chain. Organisms Numbers Oak Tree 2 Caterpillar 100 Blackbird 2 Hawk 1

Source adapted from: M.Winterbottom and C.Jones, Science SCOPE BIOLOGY, Hodder & Stoughton Educational, 2002

(a)

Complete the pyramid of numbers for this food chain.

[2]

(b)

The diagram shows the pyramid of biomass for this food chain.

(i)

Explain the size of the oak tree bar in the pyramid of biomass. _________________________________________________________ _________________________________________________________ Give two reasons why the biomass of the oak tree does not all become biomass in the caterpillar. 1 ________________________________________________________ _________________________________________________________ 2 ________________________________________________________ ________________________________________________________ [1] [1] [1]

(ii)

6

3

Explain how the structure of the ileum is adapted to the function of absorption of digested food molecules. In this question you will be assessed on your written communication skills including the use of specialist science terms. _____________________________________________________________________ _____________________________________________________________________ _____________________________________________________________________ _____________________________________________________________________ _____________________________________________________________________ _____________________________________________________________________ _____________________________________________________________________ _____________________________________________________________________ _____________________________________________________________________ _____________________________________________________________________ _____________________________________________________________________ _____________________________________________________________________ [6]

7

4

The diagram below shows a lung model.

(a)

Name the structures of a human lung modelled by parts A and B. A ____________________________________ B ____________________________________ Complete the flowchart, showing the pathway of a molecule of oxygen through the lung and into the blood. [1] [1]

(b)

[3]

8

(c)

Describe the part played by the contraction of the intercostal muscles in the breathing mechanism. ________________________________________________________________ ________________________________________________________________ ________________________________________________________________ ________________________________________________________________ ________________________________________________________________ ________________________________________________________________ [3]

9

5

The graph below shows the changes in the blood glucose level of two boys, Patrick and Glen. Both have fasted (had no food intake) for 12 hours before taking an energy drink at time 0.

(a)

Compare the changes that take place in Patrick's blood glucose levels with those of Glen. Use the information in the graph to support your answer. In this question you will be assessed on your written communication skills including the use of specialist science terms. ________________________________________________________________ ________________________________________________________________ ________________________________________________________________ ________________________________________________________________ ________________________________________________________________ ________________________________________________________________ ________________________________________________________________ ________________________________________________________________ ________________________________________________________________ ________________________________________________________________ ________________________________________________________________ ________________________________________________________________ 10 [6]

(b)

Explain the changes taking place in Glen's blood glucose levels. ________________________________________________________________ ________________________________________________________________ ________________________________________________________________ ________________________________________________________________ Blood glucose levels above 10mmol per litre result in glucose appearing in the urine, a symptom of diabetes. (i) Use evidence from the graph to identify which of the boys has diabetes. ___________________________________________________________ (ii) State another symptom of diabetes that this boy might have. ___________________________________________________________ [1] [1] [2]

(c)

11

6

The diagram below shows an experiment to investigate the diffusion of substances through a membrane.

(a)

What is diffusion? ________________________________________________________________ ________________________________________________________________ ________________________________________________________________ ________________________________________________________________ [2]

(b)

After ten minutes the starch was a blue-black colour. What caused the colour change after ten minutes? ________________________________________________________________ ________________________________________________________________ ________________________________________________________________ ________________________________________________________________ [2]

12

(c)

One student concluded that the membrane allowed substances to diffuse only in an inwards direction. (i) Describe an experiment which could be set up to test that conclusion. ___________________________________________________________ ___________________________________________________________ ___________________________________________________________ ___________________________________________________________ Give one variable, other than time, which should be kept constant during this experiment. ___________________________________________________________ ___________________________________________________________ [1] [2]

(ii)

13

7

(a)

The graph below shows the daily energy requirements for humans at different ages.

© Biology Now by K.G. Brocklehurst and Peter Fielden (1984) published by Hodder and Stoughton, "Reproduction by permission of Hodder and Stoughton Limited".

(i)

Describe the trend for males aged: 0 ­ 17 years __________________________________________________________ __________________________________________________________ 20 ­ 65 years __________________________________________________________ __________________________________________________________ Why does the body need energy? __________________________________________________________ __________________________________________________________ [1] [1] [1]

(ii)

14

(iii)

Why are the female energy requirements lower than those for males? __________________________________________________________ __________________________________________________________ [1]

(iv)

Give one other factor which affects the energy requirements of adults. __________________________________________________________ Describe, using the information on the graph, what a starvation diet would be for a 25 year old female. __________________________________________________________ __________________________________________________________ __________________________________________________________ __________________________________________________________ [2] [1]

(v)

15

(b)

The apparatus below shown was used to calculate the energy in a piece of pasta.

©Biology Lives by Morton Jenkins (2001), published by Hodder and Stoughton Limited, "Reproduced by permission of Hodder and Stonghton Limited".

4.2J of energy will increase the temperature of 1cm3 of water by 1C. The temperature of the water increased by 25C during the experiment. (i) Use the information above to help calculate the energy in the piece of pasta. Show your working.

Answer________________J [2] (ii) Suggest one reason why the results of this experiment may be considered unreliable. __________________________________________________________ __________________________________________________________ 16 [1]

The table below shows the nutritional information for pasta.

(c)

Using two pieces of evidence from the table, explain why eating pasta may be an advantage as part of a balanced diet. _______________________________________________________________ _______________________________________________________________ _______________________________________________________________ _______________________________________________________________ _______________________________________________________________ _______________________________________________________________ _______________________________________________________________ _______________________________________________________________ [4]

17

8

The diagrams below show an investigation to find out how light affects the growth of seedlings.

(a)

Which of the terms below describes how the growth of the seedlings responds to light? A Respiration B Phototropism C Geotropism D Photosynthesis Answer________________ Explain how the slow rotation of the seedlings B caused them to grow straight. _______________________________________________________________ _______________________________________________________________ _______________________________________________________________ _______________________________________________________________ _______________________________________________________________ _______________________________________________________________ 18 [3]

[1]

(b)

9

The maps show the distribution of lakes in Norway where fish stocks have been killed by acid rain.

© UNEP/Grid-Arendal

(a)

Describe the trend shown in the maps. _______________________________________________________________ _______________________________________________________________ _______________________________________________________________ [1]

(b)

Give one other biological effect of acid rain. _______________________________________________________________ _______________________________________________________________ [1]

(c)

Sulfur dioxide, produced when fossil fuels are burned in other parts of Europe, is an important gas involved in the formation of acid rain. Explain how sulfur dioxide forms acid rain and reaches lakes in Norway. _______________________________________________________________ _______________________________________________________________ _______________________________________________________________ [2]

(d)

Since 2000, the number of lakes affected by acid rain has reduced. Surveys of fish populations are one way of monitoring such environmental change. Give one other example of biotic data which can help monitor pollution. _______________________________________________________________ _______________________________________________________________ 19 [1]

10

When placed in sunlight for eight hours, the apparatus below can be used to investigate one of the requirements for photosynthesis.

© Biology Lives by Morton Jenkins (2001), published by Hodder and Stoughton Limited, "Reproduced by permission of Hodder and Stonghton Limited".

(a)

Describe and explain the results of a starch test on the leaf after eight hours. _______________________________________________________________ _______________________________________________________________ _______________________________________________________________ _______________________________________________________________ _______________________________________________________________ _______________________________________________________________ Describe how a leaf can be tested for starch. _______________________________________________________________ _______________________________________________________________ _______________________________________________________________ _______________________________________________________________ _______________________________________________________________ _______________________________________________________________ _______________________________________________________________ _______________________________________________________________ [4] [3]

(b)

20

___________________________________________ QUESTIONS CONTINUED ON THE NEXT PAGE ___________________________________________

21

11

The graph below shows changes in the area of Arctic ice.

© National Snow and Ice Data Centre

Scientists are researching reasons for these changes. The research suggests that an increase in levels of carbon dioxide leads to global warming.

The graph below shows the concentration of carbon dioxide in the atmosphere

© National Snow and Ice Data Centre

22

Describe the trends shown in each of the graphs. Explain how these trends provide evidence for the theory that changing levels of carbon dioxide in the atmosphere are linked to changes in the area of Arctic ice. In this question you will be assessed on your written communication skills, including the use of specialist science terms. ____________________________________________________________________ ____________________________________________________________________ ____________________________________________________________________ ____________________________________________________________________ ____________________________________________________________________ ____________________________________________________________________ ____________________________________________________________________ ____________________________________________________________________ ____________________________________________________________________ ____________________________________________________________________ ____________________________________________________________________ ____________________________________________________________________ [6]

Total [80]

23

___________________________________________ THIS IS THE END OF THE QUESTION PAPER ___________________________________________

24

Centre Number 71

Candidate Number

General Certificate of Secondary Education 2012

Science: Biology Unit B1 Higher Tier

[CODE] SPECIMEN PAPER

TIME 1 hour 30 minutes INSTRUCTIONS TO CANDIDATES Write your Centre Number and Candidate Number in the spaces provided at the top of your page. Write your answers in the spaces provided in this question paper. Answer all questions. INFORMATION FOR CANDIDATES The total mark for this paper is 100. Figures in brackets printed down the right-hand side of pages indicate the marks awarded to each question or part question. Quality of written communication will be assessed in questions 3, 5 and 12(e).

For Examiner's use only Question Number 1 2 3 4 5 6 7 8 9 10 11 12 Total Marks Marks

25

Answer all questions 1 The shaded areas on the maps show the distribution of lakes in Norway where fish stock have been killed by acid rain.

© UNEP/Grid-Arendal

(a)

Describe the trend shown in the maps. _______________________________________________________________ _______________________________________________________________ [1]

(b)

Give one other biological effect of acid rain. _______________________________________________________________ [1]

(c)

Sulfur dioxide, produced when fossil fuels are burned in other parts of Europe, is an important gas involved in the formation of acid rain. Explain how sulfur dioxide forms acid rain which reaches lakes in Norway. _______________________________________________________________ _______________________________________________________________ _______________________________________________________________ _______________________________________________________________ [2]

(d)

Since 2000 the number of lakes affected has reduced. Surveys of fish populations are one way of monitoring such environmental change. Give one other example of biotic data which can help monitor pollution. _______________________________________________________________ _______________________________________________________________ 26 [1]

2

When placed in sunlight for eight hours, the apparatus below can be used to investigate one of the requirements for photosynthesis.

©Biology Lives by Morton Jenkins (2001), published by Hodder and Stoughton Limited, "Reproduced by permission of Hodder and Stonghton Limited".

(a)

Describe and explain the results of a starch test on the leaf after 8 hours. _______________________________________________________________ _______________________________________________________________ _______________________________________________________________ _______________________________________________________________ _______________________________________________________________ _______________________________________________________________ [3]

(b)

Describe how a leaf can be tested for starch. _______________________________________________________________ _______________________________________________________________ _______________________________________________________________ _______________________________________________________________ _______________________________________________________________ _______________________________________________________________ _______________________________________________________________ _______________________________________________________________ [4]

27

3

The graph below shows changes in the area of Arctic ice.

© National Snow and Ice Data Centre

Scientists are researching reasons for these changes. The research suggests that an increase in levels of carbon dioxide leads to global warming.

The graph below shows the concentration of carbon dioxide in the atmosphere.

© National Snow and Ice Data Centre

28

Describe the trends shown in each graph. Explain how these trends provide evidence for the theory that changing levels of carbon dioxide in the atmosphere are linked to the changes in the area of Arctic ice. In this question you will be assessed on your written communication skills including the use of specialist science terms. ____________________________________________________________________ ____________________________________________________________________ ____________________________________________________________________ ____________________________________________________________________ ____________________________________________________________________ ____________________________________________________________________ ____________________________________________________________________ ____________________________________________________________________ ____________________________________________________________________ ____________________________________________________________________ ____________________________________________________________________ ____________________________________________________________________ [6]

29

4

The graph below shows the average changes (based on measurements from 10 healthy people) for blood glucose and insulin concentrations over a six hour period.

(a)

What evidence is shown in the graph to support the conclusion that changes in glucose concentration cause changes in insulin concentration? ________________________________________________________________ ________________________________________________________________ ________________________________________________________________ ________________________________________________________________ [2]

(b)

Explain how the body reduces the blood glucose concentration between 4.5 and 6 hours. ________________________________________________________________ ________________________________________________________________ ________________________________________________________________ ________________________________________________________________ ________________________________________________________________ ________________________________________________________________ [3]

30

5

The graphs below show the summer populations of the Pied Wagtail and Swallow in Britain between 1962 and 1965.

The Pied Wagtail is resident in Britain twelve months of each year while the Swallow is only resident during the summer months. Compare changes in the populations of these two species between 1962 and 1965. Use the data above and your scientific knowledge to explain these changes and how they may be linked. In this question you will be assessed on your written communication skills including the use of specialist science terms. _____________________________________________________________________ _____________________________________________________________________ _____________________________________________________________________ _____________________________________________________________________ _____________________________________________________________________ _____________________________________________________________________ _____________________________________________________________________ _____________________________________________________________________ _____________________________________________________________________ _____________________________________________________________________ _____________________________________________________________________ _____________________________________________________________________ 31 [6]

6

(a)

Describe the mechanism of breathing. _______________________________________________________________ _______________________________________________________________ _______________________________________________________________ _______________________________________________________________ _______________________________________________________________ _______________________________________________________________ [3]

(b)

The graph below shows changes to the volume of air breathed and the number of breaths taken while walking.

Using values from the graph, calculate the volume of each breath when walking at 2km per hour.

Answer ________________ (c) The volume of air taken in each breath changes as walking speed increases. Explain how this helps gas exchange in the lungs. ________________________________________________________________ ________________________________________________________________ ________________________________________________________________ ________________________________________________________________ 32

[1]

[2]

7

The diagram below shows part of a leaf

© GCSE Biology for CCEA, authors Rose McIlwaine and James Napier, publisher Hodder Education (2003), "Reproduced by permission of Hodder Education".

(a)

(i)

Name parts A and D. A ____________________________ D ____________________________ [1] [1]

(ii)

Describe how part B is adapted to its function. ___________________________________________________________ ___________________________________________________________ ___________________________________________________________ ___________________________________________________________ [2]

(iii)

Describe the role of part C. ___________________________________________________________ ___________________________________________________________ ___________________________________________________________ ___________________________________________________________ [2]

(iv)

On the diagram label with: an X the type of cell which carries out most photosynthesis. a Y the type of cell which controls the movement of carbon dioxide in and out of the leaf. 33 [1]

[1]

(b)

The graph shows the effect of increasing the light intensity on the rate of oxygen production, which is a method for measuring the rate of photosynthesis.

© Heinemann Coordinated Science: Higher Biology Student Book by Fosbery and McLean, ISBN: 9780435580001.

(i)

On the graph, draw a curve showing the rate of photosynthesis at 0.04% carbon dioxide and 25°C. Explain why market gardeners enrich the air in their greenhouses with carbon dioxide. ___________________________________________________________ ___________________________________________________________ ___________________________________________________________ ___________________________________________________________

[2]

(ii)

[2]

(iii)

Explain why the oxygen production is zero at point A. ___________________________________________________________ ___________________________________________________________ ___________________________________________________________ ___________________________________________________________ ___________________________________________________________ ___________________________________________________________ 34 [3]

___________________________________________ QUESTIONS CONTINUED ON THE NEXT PAGE ___________________________________________

35

8

The chart below shows the body mass index (BMI) for age percentiles of males between 2 and 20 years.

36

(a)

What is the advantage of using this percentile chart to compare the BMI of males? ________________________________________________________________ ________________________________________________________________ ________________________________________________________________ ________________________________________________________________ Paul's BMI follows the 50th percentile. Calculate the percentage change in the BMI for Paul from when he is 10 to when he is 20 years old. Show your working. [1]

(b)

Answer ________________

[3]

(c)

Explain what causes obesity. _______________________________________________________________ _______________________________________________________________ _______________________________________________________________ _______________________________________________________________ [1]

(d)

Give one example of how obesity affects society. _______________________________________________________________ _______________________________________________________________ [1]

37

9

The table below shows reaction times in response to the stimulus of a light being switched on. Age/years 20 30 40 50 60 Reaction time/milliseconds Males 240 220 260 270 380 Females 320 260 340 360 440

© Adapted from www.sizes.com/people/reaction_time.htm 19/01/11

Based on data in the above table, the percentage increase in reaction times between ages 20 and 60 was calculated. Percentage increase in reaction times between ages 20 and 60 Males Females 58% 38%

(a)

Use the above data to compare the reaction times of males and females as they age. ________________________________________________________________ ________________________________________________________________ ________________________________________________________________ ________________________________________________________________ [2]

38

(b)

The diagram shows a reflex arc.

© GCSE Single Award Science CCEA, authors Theo Laverty, James Napier and Roy White publisher Hodder Murrary, "Reproduced by permission of Hodder Education".

(i) (ii)

Name part B ________________ Describe how B is adapted to its function. ___________________________________________________________ ___________________________________________________________

[1]

[2]

(c)

A is a synapse. How does the nerve impulse pass across this synapse? ________________________________________________________________ ________________________________________________________________ ________________________________________________________________ ________________________________________________________________ [2]

(d)

Explain why the response to the drawing pin through the reflex arc would be faster than those to the light being switched on. ________________________________________________________________ ________________________________________________________________ ________________________________________________________________ ________________________________________________________________ 39 [2]

10

The diagram below shows the energy flow through a food chain.

(a)

Calculate the percentage of the energy received by the cow which is available to the human. Show your working.

Answer ________________________________ [2] (b) Explain in terms of energy, why it would be better for humans to eat barley directly. ________________________________________________________________

___________________________________________________________ ___________________________________________________________ ___________________________________________________________ ___________________________________________________________ ___________________________________________________________

(c) Fungi are one group of organisms which act as decomposers. Describe how these fungi obtain their nutrients. _______________________________________________________________ _______________________________________________________________ _______________________________________________________________ _______________________________________________________________ 40 [2] [3]

11

The diagram below shows part of the nitrogen cycle.

(a)

Name the processes A and B. A ________________________________ B ________________________________ [1] [1]

(b)

Explain how nitrate passes into plants. _______________________________________________________________ _______________________________________________________________ _______________________________________________________________ _______________________________________________________________ [2]

41

(c)

The graph below shows the concentration of different nitrogen compounds in a fish tank. A number of fish were placed in the fish tank on day 0.

(i)

Why do the ammonium compounds increase from day 0 to day 10? ___________________________________________________________ ___________________________________________________________ ___________________________________________________________ ___________________________________________________________ [2]

(ii) Why does the nitrate concentration increase? ___________________________________________________________ ___________________________________________________________ ___________________________________________________________ ___________________________________________________________ (iii) Why does the total nitrogen in the tank increase throughout the 50 days? ___________________________________________________________ ___________________________________________________________ ___________________________________________________________ ___________________________________________________________ 42 [2] [2]

___________________________________________ QUESTIONS CONTINUED ON THE NEXT PAGE ___________________________________________

43

12

Enzymes are present in the human digestive system and are used commercially in biological washing powder. (a) What is an enzyme? ________________________________________________________________ ________________________________________________________________ ________________________________________________________________ ________________________________________________________________ [2]

(b)

Proteases are one type of enzyme used in biological washing powder. An investigation was carried out to measure the performance of two different types of protease, protease X and protease Y over a range of temperatures. The results are shown on the table below. Mass of protein broken down/arbitrary units Temperature/ºC Protease X 0 5 10 15 20 25 30 35 40 45 50 55 60 0 10 30 18 2 0 0 0 0 0 0 0 0 Protease Y 0 1 3 8 19 22 29 31 30 29 23 0 0

44

Use the data for protease Y from table on the previous page to complete the graph below, comparing the effect of temperature on the two protease enzymes. The data for protease X has already been plotted.

[3] (c) One possible conclusion of this investigation is that the protease enzymes would be equally good at stain removal. (i) What evidence from the graph supports this conclusion? ___________________________________________________________ ___________________________________________________________ [1]

(ii)

What evidence does not support this conclusion? ___________________________________________________________ ___________________________________________________________ [1]

(d)

(i)

Based on this investigation, explain which of the protease enzymes would produce a more environmentally friendly washing powder. ___________________________________________________________ ___________________________________________________________ ___________________________________________________________ ___________________________________________________________ [2]

45

(ii)

The manufacturers used a combination of protease X and protease Y in their washing powder. Why would they have decided on this? ___________________________________________________________ ___________________________________________________________ [1]

(iii)

Explain why a washing powder containing only protease enzymes would not remove grease and fat stains. ___________________________________________________________ ___________________________________________________________ ___________________________________________________________ ___________________________________________________________ [2]

46

(e)

The diagram below shows a model of part of a protein molecule and a molecule of protease X.

Use information from the graph and the model above to describe and explain the activity of protease X. In this question, you will be assessed on using your written communication skills, including the use of specialist science terms. _______________________________________________________________ _______________________________________________________________ _______________________________________________________________ _______________________________________________________________ _______________________________________________________________ _______________________________________________________________ _______________________________________________________________ _______________________________________________________________ _______________________________________________________________ _______________________________________________________________ _______________________________________________________________ _______________________________________________________________ [6]

Total [100]

47

___________________________________________ THIS IS THE END OF THE QUESTION PAPER ___________________________________________

48

Centre Number 71

Candidate Number

General Certificate of Secondary Education 2013

Science: Biology Unit B2 Foundation Tier

[CODE] SPECIMEN PAPER

TIME 1 hour 30 minutes INSTRUCTIONS TO CANDIDATES Write your Centre Number and Candidate Number in the spaces provided at the top of the page. Write your answers in the spaces provided in this question paper. Answer all questions. INFORMATION FOR CANDIDATES The total mark for this paper is 90. Figures in brackets printed down the right-hand side of pages indicate the marks awarded to each question or part question. Quality of written communication will be assessed in questions 13 and 16.

For Examiner's use only Question Marks Number 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 Total Marks

49

f

Answer all questions 1 (a) Complete the table on disease-causing microorganisms. The first one has been done for you. Disease Gonorrhoea Rubella Salmonella [2] Type of microorganism Bacterium

(b)

Rubella can be spread by droplet infection. Explain what this means. _______________________________________________________________ _______________________________________________________________ [1]

50

2

The diagram shows an external view of the heart.

© Biology GCSE Edition by Geoff Jones and Mary Jones (1988) publisher Cambridge University Press.

(a)

Name the blood vessels A and B. A ________________________ B ________________________ [2]

51

(b)

The diagram shows a section through a normal coronary artery and one from a heart attack victim.

Use the diagram above to suggest how a fatty deposit on the wall of the coronary artery causes a heart attack. _____________________________________________________________________ _____________________________________________________________________ _____________________________________________________________________ _____________________________________________________________________ [3]

(c)

Give two changes in lifestyle which could reduce the risk of a further heart attack. 1 _____________________________________________________________ 2 _____________________________________________________________ [2]

52

3

The diagram below shows one strand of a DNA molecule.

(a) (b)

Complete the diagram by drawing the missing strand. Name the two chemicals which make up the backbone. _______________________________________________________________

[1]

[2]

(c)

Describe the three-dimensional shape of DNA. _______________________________________________________________ [1]

53

4

An experiment was carried out to investigate the effect of a drug on the reaction time of a car driver. A reaction timer was used to record how quickly the driver pushed a button to stop the clock after a red light had flashed. The driver was tested three times before and after taking the drug. The results were recorded in the table below. Reaction time/seconds Before taking drug 0.2 0.1 0.2 (a) After taking drug 0.3 0.5 0.6

What can be concluded about the effect of the drug? _______________________________________________________________ _______________________________________________________________ [1]

(b)

Describe how these results can be made more: reliable ________________________________________________________ _______________________________________________________________ accurate _______________________________________________________ _______________________________________________________________ [1] [1]

54

5

AIDS is a sexually transmissible infection which may be prevented using a condom. (a) Explain what is meant by a sexually transmissible infection. _______________________________________________________________ _______________________________________________________________ (b) (i) Name the type of microorganism which causes AIDS. [1] [1]

_______________________________________________________________ (ii) Describe one other way this microorganism may be transmitted.

_______________________________________________________________ _______________________________________________________________ [1]

55

6

In the sweet pea plant when a red-flowered plant is crossed with a white-flowered plant, the offspring are red-flowered plants. Let R represent the allele (gene) for red flowers. Let r represent the allele (gene) for white flowers. Complete the diagram below by writing the correct letter or letters in each circle. Two circles have been completed for you.

[4]

56

7

The diagram below shows a human life cycle.

(a) (b)

Mark with an X on the diagram above where in the life cycle meiosis occurs. Name the processes A and B. A ________________________________ B ________________________________

[1]

[1] [1]

57

(c)

The diagram shows a cell dividing by process B.

Use the diagram to complete the table. Stage Description of stage

A

[2]

B

[2]

C

[2]

58

8

The graph below shows the percentage of people with different blood groups. Blood groups are an example of variation.

(a)

State the type of variation shown in the graph. Give a reason for your choice. _______________________________________________________________ _______________________________________________________________ _______________________________________________________________ _______________________________________________________________ [2]

(b)

Give two factors which bring about variation in humans. 1 ________________________________ 2 ________________________________ [2]

59

9

The photograph below shows two forms of the peppered moth, a pale form and a black form. Birds feed on both forms of moth.

© Michael W. Tweedie / Science Photo Library

(a)

What would happen to the black moths in a woodland with light coloured tree trunks? _______________________________________________________________ _______________________________________________________________ [1]

(b)

A wood with light coloured tree trunks, had the following proportion of the two forms of moth. Percentage Pale 98 Black 2

The tree trunks became blackened with soot from a nearby factory. What would happen to the percentage of each type of moth in the wood? _______________________________________________________________ _______________________________________________________________ _______________________________________________________________ _______________________________________________________________ [2]

60

10

(a)

Down Syndrome can be caused by a mutation which results in an extra chromosome. (i) Name the test used to determine whether a foetus has Down Syndrome. _________________________________________________________ _

[1]

(ii)

The diagram below shows a foetus in the uterus. To carry out this test, a sample of cells is taken and analysed.

© GCSE Single Award Science CCEA, authors Theo Laverty, James Napier and Roy White publisher Hodder Murrary (2006), "Reproduced by permission of Hodder Education".

Draw a circle around the letter to show where cells would be collected from to carry out a test for Down Syndrome. A B C D [1]

(iii)

What ethical dilemma could parents face if the test for Down Syndrome is positive? _________________________________________________________ _________________________________________________________ [1]

61

(b)

The table below shows how the age of the mother affects the number of babies born with Down Syndrome. Age of mother in years 35 ­ 36 Risk Number of babies born with Down Syndrome per 1000 births 3

1 in 325

37 ­ 38

1 in 200

39 ­ 40

1 in 110

9

41 ­ 42

1 in 77

13

(i)

Complete the table above. Show your working.

[2] (ii) Describe how the age of the mother affects the risk of having a baby with Down Syndrome. _______________________________________________________________ _______________________________________________________________ (iii) The information in the table could be shown in a graph. What data would be plotted on the: x­axis ________________________________ y­axis ________________________________? [2] [1]

62

11

(a)

The diagrams below show a cross-section through the bladder of a healthy man and one with prostate cancer.

(i)

Give one way the cancer patient's bladder differs from that of a healthy man. _________________________________________________________ _________________________________________________________ _________________________________________________________ _________________________________________________________ [1]

(ii)

What is cancer? _________________________________________________________ _________________________________________________________ _________________________________________________________ _________________________________________________________ [2]

(b)

Men can be screened for prostate cancer. Describe how this reduces deaths due to prostate cancer. _______________________________________________________________ _______________________________________________________________ _______________________________________________________________ _______________________________________________________________ 63 [2]

12

The graph below shows the percentage of each age of young people who drink alcohol in Northern Ireland.

(a)

How do the results for 16 year olds differ from all other age groups? _______________________________________________________________ _______________________________________________________________ [1]

(b)

Describe two trends in the graph. _______________________________________________________________ _______________________________________________________________ _______________________________________________________________ _______________________________________________________________ [2]

64

13

The diagram below shows the menstrual cycle.

Use the information in the diagram to help describe the changes that occur in the female reproductive system from day 1 of the menstrual cycle leading up to pregnancy. In this question you will be assessed on using your written communication skills including the use of specialist science terms. ____________________________________________________________________ ____________________________________________________________________ ____________________________________________________________________ ____________________________________________________________________ ____________________________________________________________________ ____________________________________________________________________ ____________________________________________________________________ ____________________________________________________________________ ____________________________________________________________________ ____________________________________________________________________ ____________________________________________________________________ ____________________________________________________________________ 65 [6]

14

(a)

Complete the flow chart showing different forms of immunity using words from the list below. Antibody Foreign Acquired Natural Active Antigen

[3]

(b)

A doctor was asked at short notice to travel abroad to help rescue survivors of an earthquake. To protect him against a disease, he was given an injection which provided him with artificial passive immunity. The table shows the level of antibodies in his blood over the next 15 weeks. Time since injection/weeks 0 1 3 5 7 9 11 13 15 Level of antibodies in blood/arbitrary units 0 20 18 16 13 9 5 2 0

66

Use evidence from the table to help explain artificial passive immunity. _______________________________________________________________ _______________________________________________________________ _______________________________________________________________ _______________________________________________________________ _______________________________________________________________ _______________________________________________________________ _______________________________________________________________ _______________________________________________________________ [4]

(c)

Explain how the antibodies in the injection and phagocytes in the doctor's blood would protect him if he was infected by the disease microorganism. _______________________________________________________________ _______________________________________________________________ _______________________________________________________________ _______________________________________________________________ _______________________________________________________________ _______________________________________________________________ _______________________________________________________________ _______________________________________________________________ [4]

(d)

The minimum level of antibodies in the blood which protect against the disease is 14.5 arbitrary units. Using this information and the table in part (b) answer the following questions. (i) How long would it be safe for the doctor to stay abroad? __________________________________________________________ (ii) Explain why the doctor should return home before this time. _________________________________________________________ _________________________________________________________ 67 [1] [1]

15

The diagram below shows a potometer used to measure the water uptake of a shoot.

© Biology for AQA by Ann Fullick, publisher Pearson (2001).

(a)

Give the function of the reservoir. _______________________________________________________________ _______________________________________________________________ [1]

(b)

Describe and explain one change that would be visible in the apparatus after it was left in a warm place for 5 minutes. Change _________________________________________________________ _______________________________________________________________ Explanation _____________________________________________________ _______________________________________________________________ _______________________________________________________________ [2] [1]

68

(c)

The graph shows the effect of placing plastic bags over the leafy shoot.

The average rate of movement of the bubble in moist air is 0.9mm per minute. (i) Calculate the average rate of movement of the bubble in dry air over the first ten minutes. Show your working.

Answer ________________________________________

[2]

(ii)

Some buildings use air-conditioning which dries out the air. Using these results explain why plants in buildings with air-conditioning would need to be watered more often than plants in buildings without air-conditioning. _________________________________________________________ _________________________________________________________ _________________________________________________________ _________________________________________________________ _________________________________________________________ _________________________________________________________ 69 [3]

16

The diagram below shows the apparatus used by Pasteur in an experiment.

© Pasteur, Louis. Scientific Papers. Vol. XXXVIII, Part 7. The Harvard Classics. New York: P.F. Collier & Son, 1909-14; Bartleby.com, 2001. www.bartleby.com/38/7/. (19/10/10)

The broth in the flask remained clear for many weeks after boiling. It quickly turned cloudy when Pasteur tilted the flask until the broth reached the bend in the neck. Explain these two observations and describe how Pasteur used this experiment to argue against the theory of spontaneous generation. In this question you will be assessed on using your written communication skills including the use of specialist science terms. ____________________________________________________________________ ____________________________________________________________________ ____________________________________________________________________ ____________________________________________________________________ ____________________________________________________________________ ____________________________________________________________________ ____________________________________________________________________ ____________________________________________________________________ ____________________________________________________________________ ____________________________________________________________________ ____________________________________________________________________ ____________________________________________________________________ [6]

Total [90] 70

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72

Centre Number 71

Candidate Number

General Certificate of Secondary Education 2013

Science: Biology Unit B2 Higher Tier

[CODE] SPECIMEN PAPER

TIME 1 hour 45 minutes INSTRUCTIONS TO CANDIDATES Write your Centre Number and Candidate Number in the spaces provided at the top of this page. Write your answers in the spaces provided in this question paper. Answer all questions. INFORMATION FOR CANDIDATES The total mark for this paper is 115 marks. Figures in brackets printed down the right-hand side of pages indicate the marks awarded to each question or part question. Quality of written communication will be assessed in questions 3 and 7(c) and 14(f).

For Examiner's use only Question Marks Number 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 Total Marks

73

Answer all questions 1 The graph below shows the growth of humans.

(a)

(i)

Describe the trend in the data for humans: from 4 to 11 years of age _____________________________________ _________________________________________________________ from 12 to 20 years of age ____________________________________ _________________________________________________________ [1] [1]

(ii)

Give one other trend in the data. _________________________________________________________ _________________________________________________________ [1]

(b)

What happens to the cells of the body to bring about growth? 1 _____________________________________________________________ 2 _____________________________________________________________ [2]

74

2

The diagram below shows a potometer used to measure the water uptake of a shoot.

© Biology for AQA by Ann Fullick, publisher Pearson (2001).

(a)

Give the function of the reservoir. _______________________________________________________________ _______________________________________________________________ [1]

(b)

Describe and explain one change that would be visible in the apparatus after it was left in a warm place for 5 minutes. Change ________________________________________________________ _______________________________________________________________ Explanation _____________________________________________________ _______________________________________________________________ _______________________________________________________________ [2] [1]

75

(c)

The graph shows the effect of placing plastic bags over the leafy shoot.

The average rate of movement of the bubble in moist air is 0.9mm per minute. (i) Calculate the average rate of movement of the bubble in dry air over the first ten minutes. Show your working.

Answer ______________________

[2]

(ii)

Some buildings use air conditioning which dries out the air. Using these results, explain why plants in buildings with air conditioning would need to be watered more often than plants in buildings without air conditioning. _________________________________________________________ _________________________________________________________ _________________________________________________________ _________________________________________________________ _________________________________________________________ _________________________________________________________ 76 [3]

3

The diagram below shows the apparatus used by Pasteur in an experiment.

© Pasteur, Louis. Scientific Papers. Vol. XXXVIII, Part 7. The Harvard Classics. New York: P.F. Collier & Son, 1909-14; Bartleby.com, 2001. www.bartleby.com/38/7/. (19/10/10)

The broth in the flask remained clear for many weeks after boiling. It quickly turned cloudy when Pasteur tilted the flask until the broth reached the bend in the neck. Explain these two observations and describe how Pasteur used this experiment to argue against the theory of spontaneous generation. In this question you will be assessed on your written communication skills including the use of specialist science terms. ____________________________________________________________________ ____________________________________________________________________ ____________________________________________________________________ ____________________________________________________________________ ____________________________________________________________________ ____________________________________________________________________ ____________________________________________________________________ ____________________________________________________________________ ____________________________________________________________________ ____________________________________________________________________ ____________________________________________________________________ ____________________________________________________________________ 77 [6]

4

The diagram below shows the chromosomes in an animal cell dividing by meiosis.

(a)

Complete the diagram by drawing in the remaining cells, the re-assorted chromosomes which would produce two genetically different cells. Describe the change in the number of chromosomes during meiosis. _______________________________________________________________ _______________________________________________________________ _______________________________________________________________ _______________________________________________________________

[2]

(b)

[2]

(c)

Where are chromosomes found in a cell? _______________________________________________________________ [1]

(d)

Where in the body does meiosis occur? _______________________________________________________________ [1]

(e)

Give two differences between mitosis and meiosis. 1 ______________________________________________________________ ______________________________________________________________ 2 ______________________________________________________________ ______________________________________________________________ 78 [2]

5

The diagram below shows part of a leaf and the pathway of water vapour through a leaf.

© Biology GCSE edition by Geoff Jones and Mary Jones, publisher Cambridge University press (1987).

(a)

Name parts A, B and C. A __________________________ B __________________________ C __________________________ [1] [1] [1]

(b)

Look at the diagram. Explain the movement of water along the arrow. _______________________________________________________________ _______________________________________________________________ _______________________________________________________________ _______________________________________________________________ _______________________________________________________________ _______________________________________________________________ 79 [3]

(c)

Explain how the cuticle and guard cells help reduce the loss of water from the leaf. _______________________________________________________________ _______________________________________________________________ _______________________________________________________________ _______________________________________________________________ _______________________________________________________________ _______________________________________________________________ [3]

80

6

In vitro fertilisation is one development which helps infertile couples. (a) Explain how a woman is made to produce a large number of ova at the start of in vitro fertilisation. _______________________________________________________________ _______________________________________________________________ [1]

(b)

Describe how the ova produced are fertilised during in vitro fertilisation. _______________________________________________________________ _______________________________________________________________ _______________________________________________________________ _______________________________________________________________ [2]

(c)

Describe what must happen to the resulting embryos, if the woman is to become pregnant. _______________________________________________________________ _______________________________________________________________ _______________________________________________________________ _______________________________________________________________ [2]

(d)

There is some controversy associated with the use of in vitro fertilisation. (i) Give one argument for in vitro fertilisation. _________________________________________________________ _________________________________________________________ [1]

(ii)

Give one argument against in vitro fertilisation. _________________________________________________________ _________________________________________________________ [1]

81

7

(a)

The diagrams show the results of a breeding experiment using fruit flies.

(i)

Which allele is dominant? __________________________________________________________ [1]

(ii)

Give the genotype of the first generation fly. Genotype _________________________________________________ [1]

(b)

A male and a female from the first generation were crossed. Complete the Punnett square to show the genotypes of the second generation flies. Long wing male gametes l

L Long wing female gametes

[2]

82

(c)

Geneticists wanted to determine the genotype of a long wing fly. Describe the procedure they would have to follow to determine its genotype. In this question you will be assessed on using your written communication skills including the use of specialist science terms. _______________________________________________________________ _______________________________________________________________ _______________________________________________________________ _______________________________________________________________ _______________________________________________________________ _______________________________________________________________ _______________________________________________________________ _______________________________________________________________ _______________________________________________________________ _______________________________________________________________ _______________________________________________________________ _______________________________________________________________ [6]

83

8

The diagram shows an early human foetus attached to its placenta.

© Figure from Biology: A Modern Introduction by B S Beckett (OUP, 1986), copyright. © Oxford University Press 1976, 1982, 1986, reprinted by permission of Oxford University Press.

(a)

On the diagram, draw an arrow to show the direction of the blood flow in vessel A.

[1]

(b)

Name one substance, other than oxygen, which passes from the mother's blood to the foetus. _______________________________________________________________ [1]

(c)

Give one feature of the placenta and explain how it maintains a high rate of exchange of substances between the mother and the foetus. Feature _________________________________________________________ Explanation _____________________________________________________ _______________________________________________________________ _______________________________________________________________ _______________________________________________________________ [2] [1]

84

9

Read the following passage about blood donation and answer the questions which follow. A blood donation occurs when a healthy person voluntarily has blood taken to be used for transfusion. In Northern Ireland over 62,000 blood donations are given each year from approximately 65,000 donors. Anyone between the ages of 17 and 65 can give blood for the first time, provided there is nothing in their medical history that would endanger their own health or might make their blood unsafe for the recipient. Donors can continue to give blood up to three times a year until the age of 70. Around 500 patients each week in Northern Ireland need blood. To meet supply needs, the transfusion service tries to keep enough blood for 5 days in stock. To maintain this stock the service needs to recruit about 9,000 new donors each year. (a) Explain why a person with a medical history of anaemia would not be accepted as a blood donor. (Line 5) _______________________________________________________________ _______________________________________________________________ _______________________________________________________________ _______________________________________________________________ [2] Line 1 3 5 7 8 10

(b)

Give two reasons why a patient may need blood. (Line 8) _______________________________________________________________ _______________________________________________________________ _______________________________________________________________ _______________________________________________________________ [2]

(c)

Suggest two reasons why there is a shortage of blood donors. (Line 10) _______________________________________________________________ _______________________________________________________________ _______________________________________________________________ _______________________________________________________________ [2]

85

10

(a)

The diagram below shows the location and function of DNA in a cell.

©BBC ­ GCSE ­ Bitesize http://www.bbc.co.uk/schools/gcsebitesize

(i)

Name structure A. _________________________________________________________ [1]

(ii)

Describe the effect on the final protein of a mutation, where G (guanine) was replaced by C (cytosine), in the DNA strand. _________________________________________________________ _________________________________________________________ _________________________________________________________ _________________________________________________________ [2]

86

(iii)

Use evidence from the diagram to suggest why a mutation of a single base may not have any effect on the organism. _________________________________________________________ _________________________________________________________ [1]

(iv)

Give one environmental cause of mutations. _________________________________________________________ _________________________________________________________ [1]

(b)

(i)

Chemical analysis of DNA molecules, from a wide variety of cells, shows that the total number of molecules of A (adenine) and G (guanine) equals the total amount of T (thymine) and C (cytosine). What conclusion could early scientists have made from this observation? _________________________________________________________ _________________________________________________________ _________________________________________________________ _________________________________________________________ [2]

(ii)

Describe two other lines of evidence which enabled Watson and Crick to discover the structure of DNA. _________________________________________________________ _________________________________________________________ _________________________________________________________ _________________________________________________________ [2]

87

11

In an experiment to demonstrate natural selection, populations of fish were placed in ponds which had coarse gravel and left to breed. Some ponds had predators present while others did not.

(a)

Describe what happened to the number of fish with large spots in each of the populations after 15 generations. _______________________________________________________________ _______________________________________________________________ _______________________________________________________________ _______________________________________________________________ [2]

88

(b)

Explain how natural selection could have brought about the changes in the pond with a predator present. _______________________________________________________________ _______________________________________________________________ _______________________________________________________________ _______________________________________________________________ _______________________________________________________________ _______________________________________________________________ [3]

89

12

The diagram below shows how genetic engineering can be used to produce human insulin from bacteria. Ampicillin and tetracycline are two types of antibiotic. Study the diagram carefully and answer the questions which follows.

90

In experiments like these, some bacteria take up the plasmid (ring of DNA) containing the insulin gene. Other bacteria fail to take up a plasmid, or they take up an unmodified plasmid (a ring of DNA which has not been cut open and which does not contain the insulin gene). Complete the table by putting a tick () in the correct boxes to show which bacteria would be able to multiply in the presence of ampicillin and which bacteria would be able to multiply in the presence of tetracycline. Bacterium multiply in the presence of Ampicillin Bacterium + plasmid with the insulin gene Bacterium without a plasmid Bacterium with an unmodified plasmid [3] Tetracycline

91

13

Haemophilia is a genetic disorder which is sex-linked. The diagram below shows a family tree.

Let XH represent a normal X chromosome Xh represent an X chromosome carrying the haemophiliac allele Y represent a Y chromosome (a) Give the genotypes of the parents. Father Mother ____________________ ____________________ [2]

(b)

Give the phenotype and genotype of Janet. Phenotype ____________________ Genotype ____________________ [2]

92

(c)

Explain how Michael is not a haemophiliac even though his father is. _______________________________________________________________ _______________________________________________________________ _______________________________________________________________ _______________________________________________________________ [2]

(d)

Michael and Siobhan have children. What proportion of the children will have haemophilia? _______________________________________________________________ [1]

(e)

Why are there fewer haemophiliac females than males? _______________________________________________________________ _______________________________________________________________ [1]

93

14

A pupil carried out the following investigation to find a sugar solution which would prevent potato chips gaining or losing mass. Potato chips were weighed and placed in test tubes containing a range of sugar solutions. After 24 hours the chips were removed, dried on a paper towel and reweighed. The experiment was repeated three times for each concentration of solution. The results are shown in the table. Concentration Initial Final Change in Percentage (%) Average of sugar mass/g mass/g mass/g change in mass percentage (%) solution in (+/-) (+/-) change in mass M (Moles) (+/-) 2.5 3.3 +0.8 0 3.3 4.0 +0.7 21 2.0 2.5 +0.5 25 3.5 3.4 -0.1 -2.8 0.50 -4 3.1 3.0 -0.1 -3.2 1.4 1.3 -0.1 -7.1 3.4 2.5 -0.9 -26.5 1.00 -33 3.2 2.0 -1.2 -37.5 1.4 0.9 -0.5 -35.7 (a) Complete the table by calculating: (i) the percentage (%) change in mass for the first chip in 0 molar sugar solution. Show your working.

[2] (ii) the average percentage (%) change in mass of the three chips in 0 molar sugar solution to the nearest whole number. Show your working.

[1] (b) Why is it necessary to calculate the percentage (%) change in mass for each potato chip? _______________________________________________________________ _______________________________________________________________ 94 [1]

(c)

Draw a graph of these results, showing the average percentage (%) change in mass against the concentration of sugar solution.

[4] (d) (i) Describe the trend shown by the results. _________________________________________________________ _________________________________________________________ [1]

(ii)

Use the graph to estimate the concentration of the sugar solution which would prevent potato chips losing or gaining weight. ________________M [1]

95

(e)

Suggest two ways this investigation should be improved. _______________________________________________________________ _______________________________________________________________ _______________________________________________________________ _______________________________________________________________ [2]

(f)

The photograph shows cells from the potato chips in the strong sugar solution.

Describe and explain, in detail, the appearance of these cells. In this question, you will be assessed on your written communication skills, including the use of specialist science terms. _______________________________________________________________ _______________________________________________________________ _______________________________________________________________ _______________________________________________________________ _______________________________________________________________ _______________________________________________________________ _______________________________________________________________ _______________________________________________________________ _______________________________________________________________ _______________________________________________________________ _______________________________________________________________ _______________________________________________________________ [6]

96

15

An investigation was carried out to compare the recovery of pupils of different athletic ability after a period of strenuous exercise. Two athletic and two non-athletic pupils ran 200 metres. Their pulses were counted over the two minutes immediately after the exercise. Pulses were recorded for each of four consecutive 30 second periods. The results for each pupil are given below: Athlete A: 75, 55, 40, 30 Athlete B: 78, 53, 42, 28 Non-athlete C: 71, 64, 58, 39 Non-athlete D: 67, 58, 46, 41 (a) Organise these results into an appropriate table below. Your table should have suitable column heading and include results.

[3] 97

(b)

Describe two trends in the results. 1 ______________________________________________________________ ______________________________________________________________ 2 ______________________________________________________________ ______________________________________________________________ [2]

(c)

(i)

Which group had the greatest decrease in pulse in the first minute after exercise? __________________________________________________________ [1]

(ii)

Suggest why this group had the greatest decrease in pulse in the first minute after exercise. _________________________________________________________ _________________________________________________________ [1]

Total [115]

98

___________________________________________ THIS IS THE END OF THE QUESTION PAPER ___________________________________________

99

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100

MARK SCHEMES

101

102

General Certificate of Secondary Education

Science: Biology

GENERAL MARKING INSTRUCTIONS

103

General Marking Instructions and Mark Grids Introduction Mark schemes are intended to ensure that the GCSE examination is marked consistently and fairly. The mark schemes provide markers with an indication of the nature and range of candidates' responses likely to be worthy of credit. They also set out the criteria that they should apply in allocating marks to candidates' responses. The mark schemes should be read in conjunction with these marking instructions. Quality of candidates' responses In marking the examination papers, examiners should be looking for a quality response reflecting the level of maturity which may reasonably be expected of a 16-year-old which is the age at which the majority of candidates sit their GCSE examinations. Flexibility in marking Mark schemes are not intended to be totally prescriptive. No mark scheme can cover all the responses which candidates may produce. In the event of unanticipated answers, examiners are expected to use their professional judgement to assess the validity of answers. If an answer is particularly problematic, then examiners should seek the guidance of the Supervising Examiner. Positive marking Examiners must be positive in their marking, giving appropriate credit for description, explanation and analysis, using knowledge and understanding and for the appropriate use of evidence and reasoned argument to express and evaluate personal responses, informed insights and differing viewpoints. Examiners should make use of the whole of the available mark range of any particular question and be prepared to award full marks for a response which is as good as might reasonably be expected of a 16-year-old GCSE candidate. Awarding zero marks Marks should only be awarded for valid responses and no marks should be awarded for an answer which is completely incorrect or inappropriate. Types of mark scheme Mark schemes for questions which require candidates to respond in extended written form are marked on the basis of levels of response which take account of the quality of written communication. Other questions which require only short answers are marked on a point for point basis with marks awarded for each valid piece of information provided.

104

General Certificate of Secondary Education 2012

Science: Biology Unit B1 Foundation Tier

[CODE] SPECIMEN

MARK SCHEME

105

1

(a)

Kingdom A ­ Animals/Animalia Kingdom B ­ Plants/Plantae Kingdom C ­ Fungi Kingdom D ­ Bacteria/Monera/Prokaryote Group of organisms with similar features/characteristics Capable of reproducing fertile/viable offspring Lack of cellular organisation Considered by many (biologists) as non-living

[1] [1] [1] [1] [1] [1] [1] [1] [8]

(b)

(c)

2

(a)

Bars drawn correctly for caterpillar and blackbird All bars correctly labelled (i) Each oak tree is a very large organism/contains large amount of living material Any two from: Energy lost by respiration/as heat Energy lost to decomposers/with excretion Caterpillar cannot eat/digest parts of the oak tree

[1] [1]

(b)

[1]

(ii)

[2] [5]

106

3

Indicative content Length/folds/villi provide a large surface area Thin epithelium/membrane gives a short diffusion distance Permeable epithelium/membrane allows digested food molecules to pass through easily Good blood supply/capillaries in villi maintain a high diffusion gradient Response Candidates must use appropriate specialist terms throughout to explain, using all of the four points how the structures of the ileum are related to the function of absorption. They use good spelling, punctuation and grammar and the form and style are of a high standard. Mark

[5­6]

Candidates use some appropriate specialist terms to partially explain, using two or three of the points above, how the structures of the ileum are related to the function of absorption. They use satisfactory spelling, punctuation and grammar and the form and style are of a satisfactory standard.

[3­4]

Candidates make little use of specialist terms to explain how the structures of the ileum are related to the function of absorption or use some or all of the points above but fail to relate structure to function. They use limited spelling, punctuation and grammar.

[1­2]

Response not worthy of credit

[0]

[6]

4

(a)

A ­ Bronchus B ­ Chest/thorax wall/ribs Bronchus Bronchiole Alveolus Ribs move up and out to increase lung/chest/thorax volume [1] This decreases lung/chest/thorax/pressure [1] So it's lower than atmospheric pressure/ air moves/drawn into lungs (down the pressure gradient) [1]

[1] [1] [1] [1] [1]

(b)

(c)

[3] [8]

107

5

Indicative content Patrick's blood glucose level is 6 at the start whereas Glen's is 4 Patrick's blood glucose level rises more steeply/quicker than Glen's to reach a maximum of 20.75(20­21) for Patrick compared to a mark of 8.5(8­9) for Glen Patrick's blood glucose level is approximately 2.5 times/over twice that for Glen 2 hours after taking energy drink, Patrick's blood glucose is 11 whereas Glen's is 5 (then) sharper decline in Patrick's blood glucose level compared to Glen Response Candidates compare the changes using at least 5 of the above points. They use good spelling, punctuation and grammar and the form and style are of a high standard. Mark [5­6]

Candidates compare the changes using at least 3 of the above points. They use satisfactory spelling, punctuation and grammar and the form and style are of a satisfactory standard.

[3­4]

Candidates describe at least one of the differences indicated above. They use limited spelling, punctuation and grammar and the form and style are of a limited standard.

[1­2]

Response not worthy of credit

[0]

[6] (b) Blood glucose levels increase as glucose absorbed from digestive system Insulin then causes blood glucose levels to decrease/insulin converts glucose to glycogen/glucose is respired (i) Patrick (ii) thirst/lethargy [1] [1] [1] [1] [10]

(c)

108

6

(a)

Movement of molecules/particles From where they are in high concentration to where they are in low concentration Iodine diffused through membrane Iodine reacted with the starch/iodine caused starch to turn blue-black (i) Same apparatus/set up Iodine inside membrane and starch outside Temperature/same concentration of iodine/starch

[1] [1] [1] [1] [1] [1] [1] [7]

(b)

(c)

(ii)

109

7

(a)

(i)

0­17: Steep increase in daily energy requirement 20­65: Slowly reducing daily energy requirement Growth/repair/reproduction/movement/active transport/nerve impulses Males have more muscle Allow converse for female Activity Any two from: Below required energy Starvation Cause weight loss 25 × 20 × 4.2 [1] 2100 [1] Correct answer gets full marks Any one from: Heat loss from around the sides of the boiling tube/tin can Pasta not burning completely Heat use to raise the temperature of the thermometer/boiling tube Heat added to the pasta to start it burning

[1] [1]

(ii)

[1]

(iii)

[1] [1]

(iv) (v)

[2]

(b)

(i)

[2]

(ii)

[1]

(c)

Any two pairs [evidence + advantage] from: High fibre Reduced risk of constipation/colon cancer Low salt Reduced risk of high blood pressure/stroke Low cholesterol/fat Reduced risk of obesity/ Reduced risk of cardiovascular disease Accept named example Source of calcium Healthy bones or Source of iron Needed for formation of red blood cells/prevents anaemia

[4] [14]

110

8

(a) (b)

Phototropism Any three appropriately linked points from: Rotation causes light to be evenly distributed on all sides of seedlings Accept converse for no rotation/one-sided light This causes an even distribution/same concentration of auxin/hormone on all sides of seedling Auxin causes cells of stem to lengthen/grow All cells of stem lengthen at the same rate causing straight growth

[1]

[3] [4]

9

(a) (b) (c)

More lakes affected/fish killed each year Kills trees/plants Any two from: Rises into atmosphere Reacts/combines with water in clouds to form acid Blown by winds towards Norway Lichens/blood worms

[1] [1]

[2] [1] [5]

(d)

10

(a)

Result: No colour change/remains yellow-brown/no starch present [1] Explanation: Sodium hydroxide absorbs CO2 [1] No photosynthesis [1] Place in boiling water/reference to dipping in water after step below [1] Boil in ethanol/alcohol [1] Add iodine [1] Blue-black colour positive result [1]

[3]

(b)

[4] [7]

111

11

Indicative content Description First graph shows that the area of arctic ice is decreasing (1979­2010) Second graph shows carbon dioxide concentration/levels increasing (1959­2010) Explanation Thicker layer of carbon dioxide allows less heat energy to escape the earth/pass back into space Heat is trapped/global temperatures rise/global warming Causes increased ice melting Which is shown in first graph Response Candidates describe and explain the trends using both description points and at least 3 explanation points. They use good spelling, punctuation and grammar and the form and style are of a high standard. Mark

[5­6]

Candidates use both description points and one explanation point to describe and partially explain the trends above. They use satisfactory spelling, punctuation and grammar and the form and style are of a satisfactory standard.

[3­4]

Candidates describe or explain one of the trends using at least one of the above points. They use limited spelling, punctuation and grammar and the form and style are of a limited standard.

[1­2]

Response not worthy of credit

[0] [6] Total [80]

112

General Certificate of Secondary Education 2012

Science: Biology Unit B1 Higher Tier

[CODE] SPECIMEN

MARK SCHEME

113

1

(a) (b) (c)

More lakes affected/fish killed each year Kills trees/plants Any two from: Rises into atmosphere Reacts/combines with water in clouds to form acid Blown by winds towards Norway Lichens/blood worms

[1] [1]

[2] [1] [5]

(d)

2

(a)

Result: No colour change/remains yellow-brown/no starch present [1] Explanation: Sodium hydroxide absorbs CO2 [1] No photosynthesis [1] Place in boiling water/reference to dipping in water after step below [1] Boil in ethanol/alcohol [1] Add iodine [1] Blue-black colour positive result [1]

[3]

(b)

[4] [7]

114

3

Indicative content Description First graph shows that the area of arctic ice is decreasing (1979­2010) Second graph shows carbon dioxide concentration/levels increasing (1959­2010) Explanation Thicker layer of carbon dioxide allows less heat energy to escape the earth/pass back into space Heat is trapped/global temperatures rise/global warming Causes increased ice melting Which is shown in first graph Response Candidates describe and explain the trends using all of the above points. They use good spelling, punctuation and grammar and the form and style are of a high standard. Mark

[5­6]

Candidates use both description points and one explanation point to describe and partially explain the trends above. They use satisfactory spelling, punctuation and grammar and the form and style are of a satisfactory standard.

[3­4]

Candidates describe or explain one of the trends using at least one of the above points. They use limited spelling, punctuation and grammar, and the form and style are of a limited standard.

[1­2]

Response not worthy of credit

[0]

[6]

4

(a)

Increase in glucose before increase in insulin Changes in glucose higher than changes in insulin Accept converse Any three appropriately linked points from: Pancreas monitors blood glucose level and produces insulin Glucose is absorbed in liver Excess glucose is changed into glycogen/fat Stored in liver/around organs Causes increased respiration of glucose in other cells

[1] [1]

(b)

[3] [5]

115

5

Indicative Content Pied Wagtail [PW] [PW] population decreases during winter 62­63/between summer 62 and 63 High [PW] death rate [PW] resident during harsh winter/low temperatures/lack of food [PW] population increases summer 63 to summer 65 [PW] birth rate + [PW] immigration greater than [PW] death rate + [PW] emigration Swallow [S] [S] population remains constant/shows little change 62 and 65 [S] birth rate + [S] immigration equals [S] death rate + [S] emigration Not resident during harsh winter/low temperatures/period of food shortage due to emigration/migration Response Candidates explain the changes in the population of the two species referring to at least 2 of the above points from each category above. They use specialist terms throughout and link changes in the population of each species. They use good spelling, punctuation and grammar and the form and style are of a high standard. Mark

[5­6]

Candidates explain the changes in the population of the two species referring to at least one of the points from each category above. They use some specialist terms and link changes in the population of each species. They use satisfactory spelling, punctuation and grammar and the form and style are of a satisfactory standard.

[3­4]

Candidates explain the changes in population of only one of the species and may not use any specialist terms. They use limited spelling, punctuation and grammar and the form and style are of a limited standard.

[1­2]

Response not worthy of credit

[0]

[6]

116

6

(a)

Any three appropriately linked points from: Intercostal muscles contract moving ribs up and out Diaphragm contracts become lower/flatter Increased volume/decreased pressure Higher atmospheric pressure forces air into lung 10 ÷ 28 = 0.36 litre per breath More air breathed in per min/per breath Increases concentration gradient of O2/CO2

[3] [1] [1] [1] [6]

(b) (c)

117

7

(a)

(i)

A ­ Upper epidermis D ­ Spongy Mesophyll Clear/thin [1] allows light through [1] Accept reference to: preventing evaporation of water from leaf [1] due to its being waterproof/waxy [1] Allow gases to move/gas exchange [1] quickly/easily [1] X on palisade layer/cell Y on a guard cell Line joined to 0.04% CO2 15°C line Line levels off above 0.04% CO2 15°C line Increased CO2 increases the rate of photosynthesis Plants show increased growth/yield or more profit Low light intensity Low rate of photosynthesis/production of O2 same as rate of respiration/use of O2 Compensation point

[1] [1]

(ii)

[2] [2] [1] [1] [1] [1] [1] [1] [1] [1] [1] [15]

(iii) (iv)

(b)

(i)

(ii)

(iii)

8

(a) (b)

Can compare BMI for a range of children of the same age and sex 23, 16.5 [1] (6.5 × 100) ÷ 16.5 [1] = 39.39% [1] Accept 39.4% or 39% Correct answer gets full marks Energy intake greater than energy requirements/energy used during exercise Increased costs to NHS treating illness related to obesity/cardiovascular disease/diabetes/arthritis

[1]

[3] [1]

(c) (d)

[1] [6]

118

9

(a)

Any two from: Males faster than females/Reaction times increase with age Both males and females have fastest reaction times at age 30 Percentage increase is greater in males than females (with age) (i) (ii) Sensory neurone Any two from: long branched ends insulating sheath

[2] [1]

(b)

[2]

(c)

Diffusion [1] of a transmitter substance [1] Accept correct named example Any two points from: Shorter distance Fewer neurones/synapses No coordination by brain/only involves spinal chord

[2]

(d)

[2] [9]

10

(a)

136 ÷ 3060 × 100 4% Any three appropriately linked points from: Energy lost at each trophic level As heat/by respiration Shorter food chain/fewer steps More energy available/less energy lost in total Any two appropriately linked points from: Saprophytic nutrition/extra-cellular digestion Secretion of enzymes Absorption of digested molecules

[1] [1]

(b)

[3]

(c)

[2] [7]

119

11

(a)

A: Nitrogen fixation [1] B: Consumption/eating[1] Absorbed by roots By active transport (i) Any two appropriately linked points from: Produced by breakdown/decomposition By bacteria/saprophytes Of excretion/urine/egestion/faeces

[2] [1] [1]

(b)

(c)

[2] [1] [1]

(ii) Nitrifying bacteria Convert ammonia compounds to nitrates (iii) Any two appropriately linked points from: All the compounds contain nitrogen/part of the nitrogen cycle A continuous chain of reactions Fish continue to produce faeces etc. No nitrogen/nitrogen compounds are removed from the fish tank

[2] [10]

12

(a)

Any two from: Protein Speeds up reactions Biological catalyst Not used up in the reaction Accurate plots [-1] for each inaccuracy [max -2] Line drawn Single line through all plotted points

[2] [2]

(b)

[1]

(c)

(i) (ii)

Both remove same/similar mass of protein (Their performance) depends on temperature used Protease x ­ it works best at lower temperatures [1] so less energy used to heat water (for washing) [1] Cleans across a range of temperatures Enzymes are specific/lipase needed to digest fat/grease [1] Protease works only on protein/wouldn't breakdown grease or fat [1] 120

[1] [1]

(d)

(i)

[2] [1]

(ii) (iii)

[2]

(e)

Indicative content Protease X works because it exactly fits part of the protein molecule/reference to lock and key model Protease X works in the temperature range 0­25ºC Its optimum temperature is 10ºC when 30 arbitrary units of protein are broken down Higher temperatures/above 10ºC changes shape of enzyme Denatures the enzyme Enzyme no longer fits/compliments the protein molecule Less protein digested/broken down Mark

Response Candidates must use appropriate specialist terms throughout to describe and explain, using at least six of the points above in a logical sequence, the activity of protease X. They use good spelling, punctuation and grammar and the form and style are of a high standard.

[5­6]

Candidates use some appropriate specialist terms to partially describe and explain, using at least four of the above points in a logical sequence, the activity of protease X. They use satisfactory spelling, punctuation and grammar and the form and style are of a satisfactory standard.

[3­4]

Candidates make little use of specialist terms to describe and explain the activity of protease X and use some of the points above but fail to present them in a logical sequence. They use limited spelling, punctuation and grammar and the form and style are of a limited standard.

[1­2]

Response not worthy of credit

[0]

[6] [18] Total [100]

121

BLANK PAGE

122

General Certificate of Secondary Education 2013

Science: Biology Unit B2 Foundation Tier

[CODE] SPECIMEN

MARK SCHEME

123

1

(a)

Virus [1] Bacterium/Bacteria [1] Carried in water droplets from coughs/sneezes

[2] [1] [3]

(b)

2

(a)

A ­ Aorta B ­ Vena Cava Any three from: Deposit reduces size of lumen Less blood flows/less glucose or oxygen/less respiration To heart muscle Heart muscle dies/fails to beat Any two from: Increase exercise Stop smoking Eat less fatty food Reward other appropriate response

[2]

(b)

[3]

(c)

[2] [7]

3

(a) (b)

Complementary strand drawn with bases paired to each other Sugar [1] Phosphate [1] Double helix

[1]

[2] [1] [4]

(c)

4

(a) (b)

The drug increases reaction time Reliable: Repeat more times [1] Accurate: Measure to 2 decimal places [1]

[1]

[2] [3]

124

5

(a) (b)

Spread in sexual fluids/during intercourse (i) (ii) Virus Mother to baby/across placenta/blood-to-blood contact/named example

[1] [1] [1] [3]

6

rr and r [1] Rr, Rr [1] R,r,R,r [1] RR,Rr,Rr,rr [1]

[4] [4]

7

(a) (b)

X between adult and gamete A ­ Fertilisation [1] B ­ Mitosis [1] Stage A B C Description of stage Nucleus/nuclear membrane breaks down Chromosomes shorten/become visible Chromosomes replicate/make a copy Each chromosome has 2 strands Any two from: Chromatids separate/described; cytoplasm splits two new cells produced

[1]

[2]

(c)

[2] [2]

[2]

[9]

8

(a)

Discontinuous [1] Categoric/no in-between values [1] Genetics/inherited/from parent/genes/mutation [1] Environment/surroundings/diet/correct description [1]

[2]

(b)

[2] [4]

125

9

(a) (b)

More of the black moth eaten by birds % black increases [1] % pale decreases [1]

[1]

[2] [3]

10

(a)

(i) (ii) (iii)

Amniocentesis D circled Whether or not to continue the pregnancy or other appropriate response 1/200 × 1000/1 [1] 5 [1] Correct answer gets full marks The older the mother, the greater the risk of Down Syndrome x­axis ­ age of mother [1] y­axis ­ no. of DS babies [1]

[1] [1] [1]

(b)

(i)

[2] [1]

(ii) (iii)

[2] [8]

11

(a)

(i) (ii)

Thicker wall/smaller lumen Abnormal/uncontrolled cell division

[1] [2]

(b)

Test those at risk for presence or absence of the disease [1] Early detection improves the survival rate/no symptoms in early stages of disease [1]

[2] [5]

12

(a)

Bigger difference in percentage of boys and girls who drink alcohol/ highest percentage of boys who drink alcohol More boys drink than girls The percentage of drinkers increases with age up to 16 years

[1]

(b)

[2] [3]

126

13

Indicative content Days 6­13 or 14 uterus thickens/develops Uterus becoming more vascular Day 14 ovulation occurs/egg released From ovary Day 15­28 fertilisation occurs In oviduct Embryo/ball of cells implants in uterus lining Response Mark

Candidates must use appropriate, specialist terms throughout to describe the changes that occur in the menstrual cycle leading up to pregnancy and explain, in a logical sequence, the processes of vascularisation, fertilisation and implantation using all of [5­6] the above points. They use good spelling, punctuation and grammar and the form and style are of a high standard.

Candidates use some appropriate specialist terms to describe two changes that occur in the menstrual cycle leading up to pregnancy and partially explain, in a logical sequence, the processes of vascularisation, fertilisation and implantation using 5 or 6 [3­4] of the above points. They use satisfactory spelling, punctuation and grammar and the form and style are of a satisfactory standard.

Candidates describe some or all of the changes that occurs in the menstrual cycle leading up to pregnancy, vascularisation, fertilisation or implantation using some or all of the above points. However, these are not presented in a logical sequence. The spelling, punctuation, grammar, form and style are of a limited standard and they have made little use of specialist terms.

[1­2]

Response not worthy of credit

[0]

[6]

127

14

(a)

Natural [1] Active [1] Acquired [1] Any four from: Antibody level immediately high/20 arbitrary units Injection contains antibodies, produced by another animal Continuous decline (after 2 weeks) Body does not produce own antibodies White blood cells/lymphocytes are not stimulated by appropriate antigen Antibodies attach to antigens of disease microorganism [1] Causes clumping of microorganism [1] Stops spreading/reproduction of microorganisms [1] Phagocytes digest/break them down with enzymes [1] (i) Between 5 and 6 weeks Accept 5 weeks Any one from: May become ill/life threatening Could infect others

[3]

(b)

[4]

(c)

[4]

(d)

[1]

(ii)

[1] [13]

15

(a) (b)

Reset bubble/described Bubble moves to left/towards plant [1] Water lost from leaves/shoot [1] Due to transpiration/causes shoot to absorb more water [1] (i) 27 ÷ 10 = 2.7 [1] mm per min [1] Dry air bag has higher rate of water uptake/2.7>0.9/ Water uptake in dry air is 3 times faster [1] More water uptake/more evaporation/more transpiration [1] Less water vapour in dry bag or air conditioned building/ bigger diffusion gradient [1]

[1]

[3]

(c)

[2]

(ii)

[3] [9]

128

16

Indicative content: Microbes get trapped in swan neck/s-bend No microbes can enter flask But air can enter No decay means microbes not produced by broth Therefore spontaneous generation theory disproved Tilting allows microbes to enter broth and cause decay Response Candidates must use appropriate specialist terms throughout to explain the observations (points 1, 2 and 6) and describe, in a logical sequence, Pasteur's conclusions (points 3, 4 and 5). They use good spelling, punctuation and grammar and the form and style are of a high standard. Mark

[5­6]

Candidates use some appropriate specialist terms to explain the observations (point 2 or 6) and partially describe, in a logical sequence, Pasteur's conclusions (using 2 or 3 [3­4] of points 1, 3, 4 and 5). They use satisfactory spelling, punctuation and grammar and the form and style are of a satisfactory standard.

Candidates explain one conclusion or describe one observation, using some or all of the above points. However, these are not presented in a logical sequence. They use limited spelling, punctuation and grammar and they have made little use of specialist terms.

[1­2]

Response not worthy of credit

[0] [6] Total [90]

129

BLANK PAGE

130

General Certificate of Secondary Education 2013

Science: Biology Unit B2 Higher Tier

[CODE] SPECIMEN

MARK SCHEME

131

1

(a)

(i)

girls grow faster than boys boys grow faster than girls boys and girls have similar heights up to the age of 3 years

[1] [1] [1]

(ii) (b)

increase in cell length/mass/volume/size increase in the number of cells/cell division

[2] [5]

2

(a) (b)

Reset bubble or correct description of this Bubble moves to left/towards plant [1] Water lost from leaves/shoot [1] Due to transpiration/caused shoot to absorb more water [1] (i) 27 ÷ 10 = 2.7 [1] mm per min. [1] Dry air bag has a higher rate of water uptake/2.7 > 0.9/water uptake in dry air is 3 times faster [1] More water uptake/more evaporation/more transpiration [1] Less water vapour in dry bag or air conditioned building/bigger diffusion gradient [1]

[1]

[3]

(c)

[2]

(ii)

[3] [9]

132

3

Indicative content Microbes get trapped in swan neck/s-bend No microbes can enter flask But air can enter No decay means microbes not produced by broth Therefore spontaneous generation theory disproved Tilting allows microbes to enter broth and cause decay Response Candidates must use appropriate specialist terms throughout to explain the observations (points 1, 2 and 6) and describe, in a logical sequence, Pasteur's conclusions (points 3, 4 and 5). They use good spelling, punctuation and grammar and the form and style are of a high standard. Mark

[5­6]

Candidates use some appropriate specialist terms to explain the observations (point 2 or 6) and partially describe, in a logical sequence, Pasteur's conclusions (using 2 or 3 of points 1, 3, 4 and 5). They use satisfactory spelling, punctuation and grammar and the form and style are of a satisfactory standard.

[3­4]

Candidates explain one conclusion or describe one observation using some or all of the above points. However, these are not presented in a logical sequence. They use limited spelling, punctuation and grammar and they have made little use of specialist terms.

[1­2]

Response not worthy of credit

[0]

[6]

4

(a)

One solid and one dashed chromosome in each cell [1] Different length chromosomes in each cell [1] Diploid [1] to haploid [1] Allow [1] for: number of chromosomes halved Nucleus Testes/ovaries

[2]

(b)

[2] [1] [1]

(c) (d)

133

(e)

Any two from: Mitosis produces two daughter cells, meiosis 4 Mitosis produces identical daughter cells (clones), meiosis different Mitosis diploid, meiosis haploid (must give comparison)

[2] [8]

5

(a)

A ­ upper epidermis [1] B ­ palisade mesophyll (layer) [1] C ­ spongy mesophyll (layer) [1] Water evaporates from cell surface [1] Diffuses [1] Through air space/stomata [1] Cuticle is waterproof/waxy [1] Prevents evaporation [1] Guard cells close stomata [1]

[3]

(b)

[3]

(c)

[3] [9]

6

(a) (b)

(Given) hormone treatment Sperm sample collected [1] Mixed with ova in glass dish [1] Placed back into uterus [1] Where implantation occurs [1] (i) (ii) Gives an infertile couple the chance to have a child Some embryos may be destroyed/against nature/religious objections/too expensive Reward other appropriate responses for both (i) and (ii)

[1]

[2]

(c)

[2] [1]

(d)

[1]

[7]

134

7

(a)

(i) (ii)

Long wing/L Ll

[1] [1]

(b)

L and l (gametes correct) [1] Offspring completed correctly from gametes [1] Indicative content Carry out a test cross/back cross Cross long winged fly with short winged fly(ll) Short winged fly has double recessive genotype If offspring all long, then parent is homozygous If half offspring long and half short, parent is heterozygous

[2]

(c)

Response Candidates must use appropriate specialist terms throughout to describe a test cross (point 1) and describe, in a logical sequence, the procedure using all of points 2 to 5. They use good spelling, punctuation and grammar and the form and style are of a high standard.

Mark

[5­6]

Candidates use some appropriate specialist terms to describe a test cross (point 1) and partially describe, in a logical sequence, the procedure (using 2 or 3 of points 2 to 5). They use satisfactory spelling, punctuation and grammar and the form and style are of a satisfactory standard.

[3­4]

Candidates describe a test cross or the procedure using some or all of the above points. However, these are not presented in a logical sequence. They use limited spelling, punctuation and grammar and they have made little use of specialist terms.

[1­2]

Response not worthy of credit

[0]

[6] [10]

135

8

(a) (b) (c)

Arrow pointing from placenta to foetus Amino acids/glucose/water/hormones/drugs/other correct response Villi; increases surface area; for diffusion or thin membranes; short distance; for diffusion or good blood supply; maintains gradient; for diffusion

[1] [1]

[3] [5]

9

(a)

Any two from: Low red cell count/haemoglobin Lack of O2 transport to the tissues Would endanger patients own health/may cause heart problems Any two from: One of blood loss/accident/childbirth/haemorrhage Ongoing blood diseases/anaemia/cancer Major surgery/transplant Need for part of blood/platelets/red cells/white cells/plasma/factor VIII Any two from: 9000 new donors is a difficult target to meet Some donors/3,000 (65,000­62,000) do not donate every year Some will become too old/>70 and have to stop donating Some may become ill and not be allowed/able to donate Accept: History of blood transfusions/tattoos/recent travel to certain parts of the world/surgery/pregnancy/childbirth/CJD in family/AIDS/hepatitis

[2]

(b)

[2]

(c)

[2] [6]

10

(a)

(i) (ii)

A ­ chromosome Amino acid 3 incorporated instead of 1 [1] Different sequence of amino acids/different protein [1] CAT and TAT both code for same amino acid UV light/other suitable response

[1]

[2] [1] [1]

(iii) (iv)

136

(b)

(i)

A pairs with T or A pairs with C or G pairs with T or G pairs with C Model building [1] X-ray crystallography [1]

[2]

(ii)

[2] [9]

11

(a)

Without a predator spots remain small/lighter colour [1] With a predator spots became bigger/darker colour [1] Any three from: Better camouflage Less predation More survive Pass genes for spots on

[2]

(b)

[3] [5]

12

[1] [1] [1] [3]

13

(a)

Xh Y [1] XH XH [1] Carrier [1] XH Xh [1] Receives normal XH from mother [1] and Y from father [1] One quarter/one out of four/25%/1:3 Female haemophiliac must get Xh from both parents/father must be a haemophilic and mother a carrier

[2]

(b)

[2]

(c)

[2] [1]

(d) (e)

[1] [8]

137

14

(a)

(i)

0.8 [1] x 100 = 32 [1] 2.5 Correct answer gets full marks 26

[2] [1] [1]

(ii) (b) (c)

So results can be compared/potato chips are different sizes Axes correct way round (x ­ solution, y ­ % change) and appropriate (linear) scaling on both axes [1] Labels and units on axes [1] Accurate plots [1] Line [1]

[4]

(d)

(i) (ii)

As concentration of solution increased, % change in mass decreased 0.44 or correct reading from graph Allow ½ square tolerance

[1]

[1]

(e)

Any two from: Bigger range of solutions More replicates Measure mass to two decimal places Accept other appropriate responses

[2]

138

(f)

Indicative content Cells plasmolysed Lost water To hypertonic solution by osmosis Through selectively permeable membrane So cell membrane pulls away from cell wall Sugar solution fills space between membrane and wall Mark

Response

Candidates must use appropriate specialist terms throughout to describe and explain the appearance of the cells using at least 5 of the above points. They use good spelling punctuation and grammar and the form and style are of a high standard.

[5­6]

Candidates use some appropriate specialist terms to describe and explain the appearance of the cells using at least three of the above points. They use satisfactory spelling, punctuation and grammar and the form and style are of a satisfactory standard.

[3­4]

Candidates describe or explain the appearance of the cells using at least 1 of the above points. They use limited spelling, punctuation and grammar and they have made little use of specialist terms.

[1­2]

Response worthy of credit

[0]

[6]

[18]

139

15

(a)

Logical construction (reading across or down) Row/column heading explanatory Time units within headings

Pulse rate per 30 sec after 200 metre run 0 to 30s 30 to 60s 60 to 90s 90 to 120s

[3]

Time interval A Athletes B C Non-athletes D (b)

Athletes have higher pulse at 0 to 30 sec (accept at start) Athletes have lower pulse from 30 to 60 sec (onwards)/60 to 90 sec/90 to 120 sec Accept converse for non-athletes

(i) (ii)

[2] [1]

(c)

Athletes Athletes recover faster/fitter/hearts more efficient/heart pumps out more blood with each pulse

[1]

[7]

Total [115]

140

CONTROLLED ASSESSMENT

141

142

General Certificate of Secondary Education

GCSE Biology

SPECIMEN

CONTROLLED ASSESSMENT TASK (CAT) AND GUIDANCE NOTES FOR TEACHERS

143

Guidance on Controlled Assessment Controlled Assessment Task (CAT) ­ Food Tests: Vitamin C Scurvy is a condition caused by a lack of vitamin C in the diet. Its symptoms include gum disease and pains in the muscles and joints. Scurvy was a common problem for sailors on long voyages during the eighteenth century because their diet lacked fresh fruit and vegetables. Today, scurvy is much less common because we have more fruit and vegetables in our diet. However, vitamin C deficiency can still be a problem for certain groups of people with poor diets which don't contain citrus fruits or vegetables. Plan and carry out an investigation on one of the factors which affect vitamin C content in a range of juices. Guidance Notes for Teachers Candidates should be given the opportunity to carry out an investigation on one of the different factors which affects vitamin C content in a range of juices. One possible method would be to make up a 0.1% solution of vitamin C (100mg in 100 cm3 of water giving a concentration of 1 mg cm-3) and a 1% solution of DCPIP. Measure how much DCPIP needs to be added to this known quantity of vitamin C until the end point is reached. This amount of DCPIP corresponds to 1mg cm-3 of vitamin C. Repeat with the range of juices to be tested. Compare results with the known quantity of vitamin C to determine the quantity of vitamin C in each juice. Candidates must identify the independent variable as either comparing boiled with non-boiled juice or age of juice, for a range of juices. Candidates will be expected to process their results so that they calculate the vitamin C content for at least 3 juices in different conditions. This data must be contained within their results table and will be required for plotting a bar chart or other appropriate graph in the assessed Part C of the controlled assessment task (CAT). Note: This is only one suggested method. Candidates should be encouraged to engage with the scientific process by making their own planning decisions. During the CAT, candidates must complete Part A: Planning and Risk Assessment and Part B: Data Collection in the Pupil Response Booklet A enclosed with this document. Part A is to be carried out under a medium level of supervision and is assessed. Part B it to be carried out under a limited level of supervision and is not assessed. Candidates must complete Part C: Processing, Analysis and Evaluation in Pupil Response Booklet B enclosed with this document. Part C of the CAT is carried out under high control and is assessed.

144

Confidentiality The above notes and subsequent Candidate Response Booklet B must be kept confidential at all times and stored in a secure place e.g. a metal lockable cabinet. Health and Safety Centre must ensure that all health and safety issues are addressed and that teachers supervise candidates to ensure that there is compliance with the necessary health and safety requirements during the data collection part of the CAT. Marking Part A of the CAT should be marked using the generic mark descriptors for Planning and Risk Assessment as described in section 6.6 of the specification. Part C of the CAT should be marked using the mark scheme provided. Please refer to the specification for more detailed guidance on the procedures and controls for carrying out the controlled assessment task.

145

BLANK PAGE

146

Centre Number 71

Candidate Number

General Certificate of Secondary Education

GCSE Biology Controlled Assessment Task Candidate Response Booklet A Part A: Planning and Risk Assessment Part B: Data Collection

SPECIMEN

INSTRUCTIONS TO CANDIDATES Complete your candidate name and centre number. Answer all questions in the spaces provided. You may ask your teacher for extra paper if required. INFORMATION FOR CANDIDATES The maximum mark for this part of the task is 18. Quality of written communication will be assessed in Part A (Planning and Risk Assessment).

Planning Risk Assessment Total Teacher Mark Moderator Mark

Candidate Name: ______________________________________ Date: _____________________________

Signature of candidate: _________________________________

Signature of teacher: ___________________________________ Date: _____________________________

147

Controlled Assessment Task

Food Tests: Vitamin C Candidates should read the information below carefully.

Scurvy is a condition caused by a lack of vitamin C in the diet. Its symptoms include gum disease and pains in the muscles and joints. Scurvy was a common problem for sailors on long voyages during the eighteenth century because their diet lacked fresh fruit and vegetables. Today, scurvy is much less common because we have more fruit and vegetables in our diet. However, vitamin C deficiency can still be a problem for certain groups of people with poor diets which don't contain citrus fruits.

Plan and carry out an investigation on one of the factors which affect vitamin C content in a range of juices.

148

Part A: Planning and Risk Assessment When completing your Hypothesis and Plan you will be assessed on your written communication skills, including the use of specialist, scientific terms. Your Hypothesis (Say what you think will happen.) ________________________________________________________________________________ ________________________________________________________________________________ ________________________________________________________________________________ ________________________________________________________________________________ ________________________________________________________________________________ ________________________________________________________________________________ ________________________________________________________________________________ ________________________________________________________________________________ ________________________________________________________________________________ ________________________________________________________________________________ ________________________________________________________________________________

149

Your Plan

________________________________________________________________________________ ________________________________________________________________________________ ________________________________________________________________________________ ________________________________________________________________________________ ________________________________________________________________________________ ________________________________________________________________________________ ________________________________________________________________________________ ________________________________________________________________________________ ________________________________________________________________________________ ________________________________________________________________________________ ________________________________________________________________________________ ________________________________________________________________________________

150

________________________________________________________________________________ ________________________________________________________________________________ ________________________________________________________________________________ ________________________________________________________________________________ ________________________________________________________________________________ ________________________________________________________________________________ ________________________________________________________________________________ ________________________________________________________________________________ ________________________________________________________________________________ ________________________________________________________________________________ ________________________________________________________________________________ ________________________________________________________________________________ ________________________________________________________________________________ ________________________________________________________________________________ ________________________________________________________________________________ ________________________________________________________________________________ ________________________________________________________________________________ ________________________________________________________________________________ ________________________________________________________________________________ ________________________________________________________________________________ ________________________________________________________________________________ ________________________________________________________________________________ ________________________________________________________________________________ ________________________________________________________________________________ ________________________________________________________________________________ ________________________________________________________________________________ 151

Risk Assessment

152

Part B: Data Collection Draw a blank results table in which to record and process your data.

153

BLANK PAGE

154

Centre Number 71

Candidate Number

General Certificate of Secondary Education

GCSE Biology Controlled Assessment Task Candidate Response Booklet B Part C: Processing, Analysis and Evaluation

SPECIMEN

INSTRUCTIONS TO CANDIDATES Complete your candidate name and centre number. Answer all questions in the spaces provided. You may ask your teacher for extra graph paper or lined paper if required. INFORMATION FOR CANDIDATES The maximum mark for this part of the task is 27. You may consult all the information and results contained in your Candidate Response Booklet A.

Question 1 2 3 4 5 6 7 Total Teacher Mark Moderator Mark

Candidate Name: ______________________________________ Date: _____________________________

Signature of candidate: _________________________________

Signature of teacher: ___________________________________ Date: _____________________________

155

1

On the graph grid below, draw an appropriate graph to show your results. Remember to include a title and to label each of the axes. Where appropriate, state the units used.

[3]

156

2

Use your results and information from your graph to explain what you found out in your investigation and whether this agreed with the hypothesis you made at the start. ____________________________________________________________________ ____________________________________________________________________ ____________________________________________________________________ ____________________________________________________________________ ____________________________________________________________________ ____________________________________________________________________ ____________________________________________________________________ ____________________________________________________________________ ____________________________________________________________________ ____________________________________________________________________ [5]

3

(a)

State one factor that you kept the same in your investigation. Explain how this made it a fair test. _______________________________________________________________ _______________________________________________________________ _______________________________________________________________ _______________________________________________________________ _______________________________________________________________ _______________________________________________________________ _______________________________________________________________ [2]

157

(b)

If you were doing your experiment again, state one improvement you would make and explain why you would make it. _______________________________________________________________ _______________________________________________________________ _______________________________________________________________ _______________________________________________________________ [2]

4

(a)

You may have repeated readings in your experiment. Give two reasons why this would be a good idea. _______________________________________________________________ _______________________________________________________________ _______________________________________________________________ _______________________________________________________________ [2]

(b)

Are there any readings that you would repeat again if you could? Explain your answer. _______________________________________________________________ _______________________________________________________________ _______________________________________________________________ _______________________________________________________________ [2]

158

___________________________________________ QUESTIONS CONTINUED ON THE NEXT PAGE ___________________________________________

159

5

The following graphs show information from investigations to measure the vitamin C content of a range of fruit and vegetable juices under different conditions. Graph 1

Graph 2

160

Graph 3

(a)

Which graph is from an investigation most similar to your own? Explain your answer. _______________________________________________________________ _______________________________________________________________ _______________________________________________________________ _______________________________________________________________ [2]

The following questions relate to the graph you have chosen in part 5(a). (b) Describe fully the trend shown by the results on the graph and compare this trend with the results for your own investigation. _______________________________________________________________ _______________________________________________________________ _______________________________________________________________ _______________________________________________________________ _______________________________________________________________ _______________________________________________________________ 161 [3]

6

You will need to look at graphs 1, 2 and 3 to answer this question. (a) Using evidence from these given graphs, describe the results for orange juice. _______________________________________________________________ _______________________________________________________________ _______________________________________________________________ _______________________________________________________________ (b) Explain why there are different height bars for tomato juice. _______________________________________________________________ _______________________________________________________________ [1] [2]

7

Evaluate your own results and the information in graphs 1, 2 and 3 to make some recommendations on how to increase the amount of vitamin C in our diet. You must use the available data/information to support your answer. ____________________________________________________________________ ____________________________________________________________________ ____________________________________________________________________ ____________________________________________________________________ ____________________________________________________________________ ____________________________________________________________________ [3]

162

General Certificate of Secondary Education

GCSE Biology Controlled Assessment

[CODE] SPECIMEN

MARK SCHEME

(Part C ­ Processing, Analysis and Evaluation)

163

GCSE Biology ­ Controlled Assessment Task Food Tests: Vitamin C Marking Guidelines Question 1 Answer Both axes drawn, scaled and labelled correctly At least three bars drawn correctly Bars of equal width Gaps between bars (discrete data) Mark [1] Tolerance for plotting top of each bar is +/- 2mm If bar chart not drawn: Allow [1] for three points correctly plotted Where appropriate allow [1] for graph line drawn Additional Guidance

[1]

[1]

2

Valid statement which reflects the trend seen Reference to graph/results Links independent and dependent variables Correctly states if outcomes agree with hypothesis Valid statement explaining why their conclusion either agrees of disagrees with their hypothesis

[1] [1]

[1]

[1]

[1] [1]

3(a)

Any controlled variable Only one factor can be changed

[1] [1]

3(b)

State one valid improvement Explains correctly why improvement should be made

[1]

164

Question 4(a)

Answer To ensure they are similar/ensure consistency To calculate average (to reduce errors)

Mark [1]

Additional Guidance

[1]

4(b)

Yes [1]: refer to reading that is anomalous in their results [1] or No [1]: All readings are similar/fit into trend [1] Graph 1 [1] Because fresh (natural) and boiled juices are being compared [1] or Graph 2 [1] Because fresh (natural) and juices left for a time are being compared [1] Graph 1: When the juice was boiled the vitamin C content was reduced [1] To about half of what it had been before boiling [1] or Graph 2: When the juice has been left (for 48 hours) the vitamin C was reduced [1] Slightly/not by a significant amount or equivalent [1] or Graph 3: Processed juice contained less vitamin C than fresh (natural) juice [1] Only slightly reduced/not reduced by a significant amount [1] Valid comparison with their own results

[2]

5(a)

Mark according to agreement with independent variable investigated in candidate's own investigation [2] No mark awarded for graph 3

5(b)

Award marks as appropriate to graph chosen in part 5(a) even if incorrect graph chosen in part 5(a) (Carry error through/CET)

[2]

[1]

165

Question 6(a)

Answer Amount of vitamin C in orange juice is reduced by boiling and/or leaving for a time in the fridge; Boiling has a greater effect/causes a greater reduction that leaving for a time in the fridge

Mark

Additional Guidance

[1]

[1] Or equivalent [1]

6(b)

The two graphs have different scales Any 3 from: Blackcurrant juice at 1.52 (mg cm-3) is the richest source of vitamin C or correct ref to higher reading from own results. Carrot juice at 0.6 (mg cm-3) is the least rich source of vitamin C or correct ref to lower reading from own results. Correct unit used in one of readings: mg cm-3/mg 100cm-3 Referring to another poor source of vitamin C and citing amount contained Referring to another rich source of vitamin C and citing amount contained Fresh sources richer than boiled/ageing sources

7

Accept value of 152mg 100cm-3 or 152mg/100cm3 for blackcurrant

[3]

Accept mg/cm3, mg/ml.mg ml-1, mg/100cm3, mg/100ml Allow mark if correct unit given in (i) or (ii) No mark if incorrect unit given for (i) or (ii)

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