A-Level Biology: Summer work

1

A-Level Biology: Summer work

Because of the extended holiday period, students are expected to complete 20 hours of work in order to prepare

for A-level Biology next year. Please complete the following work.

1. Our usual summer worksheet which contains 2 pages of questions (see pages 2-3). This is to be completed

on a separate sheet of paper (written or typed) and handed in during your first Biology lesson in September.

2. A list of all the keywords from Terms 1 & 2. You must research these key terms and come up with a

definition for them. During the course, you can tick them off as each one comes up. See pages 4-9.

3. Exam question pack which contains data analysis, data interpretation, and graph work questions. These are

the questions that a lot of students can struggle with at A-level, and it will be beneficial to familiarise

yourselves with these types of question early. See pages 10-40. The mark scheme for these is attached as

well, so you can self-mark your answers. See pages 41-56. Evidence that these have been completed must be

shown in September.

4. Lastly, links to 6 scientific novels which have been highly recommended by various teachers appear below.

These will broaden your minds to Biology beyond the exam specification and will give you a deeper

appreciation for Science. The expectation is that you read at least two of these novels. Audible has made a

few of these free to download during these difficult times.

https://www.amazon.co.uk/First-Cell-Human-Pursuing-

Cancer/dp/B07YYGQL4B/ref=sr_1_1?dchild=1&keywords=the+first+cell&qid=1586173757&s=books&sr=1-1

https://www.amazon.co.uk/Napoleons-Buttons-Penny-Couteur-

ebook/dp/B001NQGN24/ref=sr_1_1?dchild=1&keywords=Napoleons+buttons&qid=1586173806&s=books&sr=1-1

https://www.amazon.co.uk/Gulp-Adventures-Alimentary-Mary-Roach-

ebook/dp/B07ZWK911Z/ref=sr_1_1?dchild=1&keywords=gulp&qid=1586173771&s=books&sr=1-1

https://www.amazon.co.uk/Violinists-Thumb-extraordinary-stories-written-

ebook/dp/B008H1SIVM/ref=sr_1_1?dchild=1&keywords=the+violinists+thumb&qid=1586173823&sr=8-1

https://www.amazon.co.uk/Origin-Species-Sabina-

Radeva/dp/0141388501/ref=sr_1_1?crid=1BRQHO0RH2YTL&dchild=1&keywords=the+origin+of+species&qid=158

6173787&s=books&sprefix=the+ori%2Caps%2C171&sr=1-1

https://www.amazon.co.uk/Frogs-Flies-Dandelions-Making-

Species/dp/0198503938/ref=sr_1_1?dchild=1&keywords=Frogs+flies+and+dandelions&qid=1586173842&sr=8-1

2 PTO

A-Level Biology

The following sets of twenty questions encompass the theory you will cover in the first two Biology topics

in year 12. Answer in full sentences on lined paper and bring along to you first Biology lesson.

Biological molecules

1. Define metabolism (2 marks)

2. Name the bonding found in metals (1 mark)

3. How do you test for reducing sugars? (2 marks)

4. What two monosaccharide's join to form lactose? (2 marks)

5. Describe the test for starch (2 marks)

6. What is the main role of cellulose? (1 mark)

7. What are the two main groups of lipids? (2 marks)

8. Draw the structure of an amino acid (1 mark)

9. What are phospholipids made up of? (2 marks)

10. Name 2 properties of water (2 marks)

11. What are the 4 structures of protein molecules? (4 marks)

12. What is a condensation reaction? (1 mark)

13. What bond forms to form dipeptides? (1 mark)

14. What is a hydrolysis reaction? (1 mark)

15. True or false: Glycogen is insoluble (1 mark)

16. What are the bonds found in starch molecules? (1 mark)

17. If glucose joins to glucose then what is formed? (1 mark)

18. Describe the structure of ATP? (3 marks)

19. What is a polar molecule? (2 marks)

20. What colour should the solution go if reducing sugars are present? (1 mark)

/33

3 PTO

Cell structure

1. How do you calculate magnification? (3 marks)

2. What is homogenation? (1 mark)

3. Name two advantages of using an electron microscope (2 marks)

4. Name 2 limitations of using a Transmission Electron Microscope (TEM) (2 marks)

5. What do you need to calibrate an eyepiece graticule? (1 mark)

6. True or false: Eukaryotic cells contain membrane bound organelles. (1 mark)

7. What are cristae? (1 mark)

8. What 3 parts make up chloroplasts (3 marks)

9. What are the 2 parts of the endoplasmic reticulum? (2 marks)

10. Name the 2 types of ribosomes (2 marks)

11. Name an organ system (1 mark)

12. State the role of the capsule in bacterial cells (1 mark)

13. What are prokaryotic cell walls made of? (1 mark)

14. What is the definition of a tissue (1 mark)

15. True or false: viruses are larger than bacteria (1 mark)

16. Name a plant organ (1 mark)

17. Name the chemical that is used to make the cell wall of fungi (1 mark)

18. What is the role of attachment proteins in viruses (1 mark)

19. Describe epithelial tissues (2 marks)

20. What is a tonoplast? (1 mark)

/29

4

Term 1 & 2 Key Words Biological Molecules

Covalent Bond

Ionic Bond

Hydrogen Bond

Polar Molecule

Monomer

Polymer

Polymerisation

Condensation

Hydrolysis

Metabolism

Mole

Molar (M) Solution

Carbohydrate

Monosaccharide

Organic Molecule

Disaccharide

Polysaccharide

Hexose sugar

Glucose

Reducing Sugar

Reducing sugar test

Benedict’s reagent

Glycosidic bond

Non-reducing sugar

Non-reducing sugar test

Starch

Glycogen

Cellulose

Alpha glucose

Beta glucose

Lipid

Triglyceride

Fatty acid

Glycerol

Saturated fatty acid

Mono-unsaturated fatty acid

Poly-unsaturated fatty acid

5

Phospholipid

Hydrophilic

Hydrophobic

Emulsion test

Protein

Amino acid

Amino group

Carboxyl group

R-group

Peptide bond

Polypeptide

Primary protein structure

Secondary protein structure

Tertiary protein structure

Disulfide bridge

Quaternary protein structure

Biuret test

Enzymes

Enzyme

Activation energy

Active Site

Substrate

Enzyme-substrate complex

Complimentary

Specific

Induced fit

Lock and key

Rate of reaction

Kinetic Energy

pH

Inhibitor

Competitive inhibitor

Non-competitive inhibitor

DNA

DNA

Nucleotide

Polynucleotide

6

Phosphodiester bond

Organic base

RNA

Complimentary base pairing

Double helix

Semiconservative replication

DNA helicase

DNA polymerase

ATP (Adenosine triphosphate)

ADP

ATP Synthase

ATP Hydrolase

Polymerases

Gas Exchange

Surface area: volume ratio

Exchange surface

Concentration gradient

Tracheae

Tracheoles

Spiracle

Gill

Gill filaments

Gill lamellae

Countercurrent flow

Stomata

Guard cells

Spongy mesophyll

Xerophyte

Lungs

Ventilation

Trachea

Bronchi

Bronchioles

Alveoli

Inspiration

Expiration

Diaphragm

Rib cage

7

Intercostal muscles

Cell Structure

Magnification

Resolution

Micrometer

Nanometer

Light Microscope

Electron microscope

Scanning Electron Microscope (SEM)

Transmission electron microscope (TEM)

Cell fractionation

Homogenation

Ultracentrifugation

Graticule

Eukaryote

Organelle

Nucleus

Mitochondria

Chloroplast

Rough endoplasmic reticulum (RER)

Smooth endoplasmic reticulum (SER)

Golgi

Lysosome

Ribosome

Cell Wall

Vacuole

Tissue

Organ

Organ system

Prokaryote

Bacteria

Plasmid

Flagellum

Virus

Capsid

Attachment Protein

Cell Division

Mitosis

8

Daughter cell

Chromatid

Centromere

Interphase

Prophase

Metaphase

Anaphase

Telophase

Cytokinesis

Spindle fibres

Centrioles

Equator

Binary Fission

Cancer

Tumour

Transport across membrane

Plasma Membrane

Phospholipid

Bilayer

Protein Channel

Carrier Protein

Glycoprotein

Glycolipid

Cholesterol

Permeability

Fluid mosaic model

Diffusion

Facilitated diffusion

Osmosis

Water potential

Isotonic

Active transport

Co-transport

Immunity

Pathogen

Self

Foreign (non-self)

Antigen

Lymphocyte

9

Phagocyte

Phagocytosis

Lysosome

Phagosome

Antigen-presentation

Cell-mediated immunity

T Cells

Clonal Selection

TH cells (helper T cell)

TC cells (cytotoxic T cells)

Humoral Immunity

B Cells

Plasma B Cells

Antibody

Memory B Cells

Monoclonal antibodies

Primary Response

Secondary response

Passive immunity

Active immunity

Natural immunity

Artificial immunity

Vaccination

Herd immunity

Antigenic variability

HIV

Reverse transcriptase

Retrovirus

mRNA

AIDS

ELISA test

Antibiotic

10

Q1. Metabolism is the sum of all the chemical reactions in the cells of the body.

One metabolic reaction is the formation of lipids.

(a) Give one other metabolic reaction in cells.

___________________________________________________________________

___________________________________________________________________

(1)

Table 1 shows the mean metabolic rate of humans of different ages.

Table 1

Age in

years

Mean metabolic rate in kJ/m2/hour

Males Females

5 53 53

15 45 42

25 39 35

35 37 35

45 36 35

(b) What two conclusions can be made from the data in Table 1?

Tick two boxes.

As age increases, mean metabolic rate of males and

females increases.

Males have a higher metabolic rate than females after

five years of age.

The mean metabolic rate of females decreases faster

than males up to 25 years of age.

The mean metabolic rate of males and females decreases

more quickly after the age of 35.

There is no relationship between age and mean

metabolic rate.

(2)

(c) Calculate the percentage decrease in the mean metabolic rate of males between 5 years and

45 years of age.

Use the equation:

11

Give your answer to 3 significant figures.

___________________________________________________________________

___________________________________________________________________

___________________________________________________________________

___________________________________________________________________

Percentage decrease = ___________________

(3)

Regular exercise can increase metabolic rate.

Two people did five minutes of gentle exercise from rest.

Table 2 shows the effect of the exercise on their heart rates.

Table 2

Time in

minutes

Heart rate in beats per

minute

Person R Person S

0 (at rest) 60 78

1 76 100

2 85 110

3 91 119

4 99 129

5 99 132

(d) Describe two differences in the response of person R and person S to the exercise.

Use information from Table 2.

1. _________________________________________________________________

___________________________________________________________________

2. _________________________________________________________________

___________________________________________________________________

(2)

(e) Complete the line graph below for person S.

You should:

• add the scale to the x axis

12

• label the x axis.

(4)

(f) After five minutes of exercise, the heart rate of person S was 132 beats per minute. When

person S rested, his heart rate decreased steadily at a rate of 12 beats every minute.

Calculate how much time it would take the heart rate of person S to return to its resting

rate.

___________________________________________________________________

___________________________________________________________________

___________________________________________________________________

Time = ___________________ minutes

(2)

(g) A student made the following hypothesis about the heart rate of smokers and non-smokers

during exercise.

“During exercise, the heart rate of smokers increases more than

the heart rate of non-smokers.”

Design an investigation that would allow you to test this hypothesis.

13

___________________________________________________________________

___________________________________________________________________

___________________________________________________________________

___________________________________________________________________

___________________________________________________________________

___________________________________________________________________

___________________________________________________________________

___________________________________________________________________

___________________________________________________________________

___________________________________________________________________

___________________________________________________________________

___________________________________________________________________

___________________________________________________________________

___________________________________________________________________

___________________________________________________________________

___________________________________________________________________

___________________________________________________________________

___________________________________________________________________

___________________________________________________________________

(6)

(Total 20 marks)

Q2. In South Asia, forests are being cleared to grow palm oil trees. The palm oil is mainly used to

produce fuel for motor vehicles.

The graph shows the production of palm oil in one South Asian country.

14

(a) Calculate the mean increase in palm oil production per year for the five year period 2000 to

2005.

Show clearly how you work out your answer.

___________________________________________________________________

___________________________________________________________________

Mean increase = _______________ millions of tonnes per year

(2)

(b) Clearing forests and replacing the forests with palm oil trees to produce fuel for motor

vehicles will affect the composition of the atmosphere.

Explain how.

___________________________________________________________________

___________________________________________________________________

___________________________________________________________________

___________________________________________________________________

___________________________________________________________________

___________________________________________________________________

___________________________________________________________________

___________________________________________________________________

___________________________________________________________________

___________________________________________________________________

15

___________________________________________________________________

___________________________________________________________________

___________________________________________________________________

___________________________________________________________________

(5)

(Total 7 marks)

Q3. (a) The graph shows the effect of pH on the activities of three enzymes, X, Y and Z.

These enzymes help to digest food in the human digestive system.

Each enzyme is produced by a different part of the digestive system.

pH

(i) What is the optimum (best) pH for the action of enzyme Z?

__________________

(1)

(ii) The stomach makes a substance that gives the correct pH for enzyme action in the

human stomach.

Name this substance. ____________________________________________

(1)

(iii) Which enzyme, X, Y or Z, will work best in the human stomach?

__________________

(1)

(b) In this question you will be assessed on using good English, organising information clearly and using

specialist terms where appropriate.

Different parts of the human digestive system help to break down molecules of fat so that

they can be absorbed into the body.

Describe how.

16

To gain full marks you should refer to:

• the enzyme and where the enzyme is produced

• the products of digestion

• any other chemicals involved.

___________________________________________________________________

___________________________________________________________________

___________________________________________________________________

___________________________________________________________________

___________________________________________________________________

___________________________________________________________________

___________________________________________________________________

___________________________________________________________________

___________________________________________________________________

___________________________________________________________________

___________________________________________________________________

___________________________________________________________________

___________________________________________________________________

___________________________________________________________________

___________________________________________________________________

___________________________________________________________________

___________________________________________________________________

(6)

(Total 9 marks)

Q4. Biological detergents contain protease enzymes.

(a) The drawings show some apparatus and materials.

17

In this question you will be assessed on using good English, organising information clearly and using

specialist terms where appropriate.

Describe how you would use the apparatus and materials shown in the drawings to find the

best temperature for removing stains from clothing.

You should include how you would make the investigation a fair test.

___________________________________________________________________

___________________________________________________________________

___________________________________________________________________

___________________________________________________________________

___________________________________________________________________

___________________________________________________________________

___________________________________________________________________

___________________________________________________________________

___________________________________________________________________

___________________________________________________________________

___________________________________________________________________

___________________________________________________________________

___________________________________________________________________

___________________________________________________________________

18

___________________________________________________________________

___________________________________________________________________

(6)

(b) In a similar investigation a student investigated the effect of pH on the time taken to

remove a stain from pieces of cloth.

The table shows the student’s results.

pH of detergent solution

1 2 3 4 5 6 7 8 9

Time taken to

remove

stain in minutes

20 19 17 14 10 4 8 12 16

(i) On the graph paper below draw a graph to show the student’s results.

• Add a suitable scale and label to the y axis.

• Plot the student’s results.

• Draw a line of best fit.

pH of detergent solution

(4)

(ii) Which is the best pH for using the detergent?

pH _____________________________

(1)

(c) Scientists investigated the stability of a protease enzyme. The protease enzyme was

19

extracted from plants.

The scientists:

• pre-incubated samples of the enzyme at various temperatures for 30 minutes

• put each sample on ice for a further 10 minutes

• measured the percentage (%) remaining activity of the enzyme in each sample.

This was done by incubating each sample with protein at 37 °C for 6 hours.

The graph shows the scientists’ results.

Pre-incubation temperature in °C

The scientists recommended that the enzyme could be used in detergents at a temperature

of 60 °C.

Suggest why the scientists recommended a temperature of 60 °C.

Use information from the graph and your own scientific knowledge in your answer.

___________________________________________________________________

___________________________________________________________________

___________________________________________________________________

___________________________________________________________________

___________________________________________________________________

___________________________________________________________________

(3)

(Total 14 marks)

Q5. The graph shows the core body temperature and the skin surface temperature of a cyclist before,

during and after a race.

20

Start

of race

(a) (i) When the cyclist finished the race, his core body temperature started to decrease.

How long did the race last?

______________________________________________________________

(1)

(ii) Describe and explain the different patterns shown in the core body temperature and

skin surface temperature between 09.15 and 10.15.

______________________________________________________________

______________________________________________________________

______________________________________________________________

______________________________________________________________

______________________________________________________________

______________________________________________________________

______________________________________________________________

______________________________________________________________

______________________________________________________________

______________________________________________________________

______________________________________________________________

______________________________________________________________

(6)

(iii) After 10.30, the core body temperature decreased.

21

Explain how changes in the blood vessels supplying the skin caused the skin surface

temperature to increase.

______________________________________________________________

______________________________________________________________

______________________________________________________________

______________________________________________________________

______________________________________________________________

______________________________________________________________

(2)

(b) During the race, the cyclist’s blood glucose concentration began to decrease.

Describe how the body responds when the blood glucose concentration begins to

decrease.

___________________________________________________________________

___________________________________________________________________

___________________________________________________________________

___________________________________________________________________

___________________________________________________________________

___________________________________________________________________

___________________________________________________________________

___________________________________________________________________

(3)

(Total 12 marks)

Q6. It is important to remove waste products from our bodies.

Healthy kidneys help to keep our internal environment constant.

(a) Describe how a healthy kidney produces urine.

___________________________________________________________________

___________________________________________________________________

___________________________________________________________________

___________________________________________________________________

___________________________________________________________________

___________________________________________________________________

22

___________________________________________________________________

___________________________________________________________________

___________________________________________________________________

___________________________________________________________________

(5)

(b) A child has kidney failure and is treated with dialysis.

Before the dialysis starts, the doctor measures the concentration of urea and glucose in the

child’s blood.

The table shows the results.

Concentration in the

blood before dialysis

starts in mmol per dm3

Urea 28

Glucose 6

The child has a normal blood glucose concentration.

(i) Sketch a graph on Figure 1 to suggest what will happen to the concentration of urea

in the blood during dialysis.

(1)

(ii) Sketch a graph on Figure 2 to suggest what will happen to the concentration of

glucose in the blood during dialysis.

23

(1)

(c) (i) Another way of treating kidney failure is with a kidney transplant.

A transplanted kidney can be rejected.

Explain why the new kidney may be rejected.

______________________________________________________________

______________________________________________________________

______________________________________________________________

______________________________________________________________

______________________________________________________________

______________________________________________________________

(3)

(ii) Describe one way in which doctors try to prevent kidney rejection.

______________________________________________________________

______________________________________________________________

(1)

(Total 11 marks)

Q7. A student plans an investigation using mould.

(a) Mould spores are hazardous.

Give one safety precaution the student should take when doing this investigation.

___________________________________________________________________

24

___________________________________________________________________

(1)

(b) A student made the following hypothesis about the growth of mould:

‘The higher the temperature, the faster the growth of mould’.

The student planned to measure the amount of mould growing on bread.

The student used the following materials and equipment:

• slices of bread

• sealable plastic bags

• a knife

• a chopping board

• mould spores.

Describe how the materials and equipment could be used to test the hypothesis.

___________________________________________________________________

___________________________________________________________________

___________________________________________________________________

___________________________________________________________________

___________________________________________________________________

___________________________________________________________________

___________________________________________________________________

___________________________________________________________________

(4)

(c) Give one variable the student should control in the investigation.

___________________________________________________________________

(1)

(d) Another student did a similar investigation.

The diagram below shows the results.

25

Determine the rate of mould growth at 42 °C between day 2 and day 7.

___________________________________________________________________

___________________________________________________________________

Rate of mould growth = _______________ units per day

(2)

(e) The growth of mould shows decomposition of the bread.

Give a conclusion about decomposition from the results in the diagram above.

___________________________________________________________________

___________________________________________________________________

(1)

(Total 9 marks)

Q8. An athlete ran as fast as he could until he was exhausted.

(a) Figure 1 shows the concentrations of glucose and of lactic acid in the athlete’s blood at the

start and at the end of the run.

26

(i) Lactic acid is made during anaerobic respiration.

What does anaerobic mean?

______________________________________________________________

______________________________________________________________

(1)

(ii) Give evidence from Figure 1 that the athlete respired anaerobically during the run.

______________________________________________________________

______________________________________________________________

(1)

(b) Figure 2 shows the effect of running on the rate of blood flow through the athlete’s

muscles.

27

(i) For how many minutes did the athlete run?

Time = ______________________ minutes

(1)

(ii) Describe what happens to the rate of blood flow through the athlete’s muscles during

the run.

Use data from Figure 2 in your answer.

______________________________________________________________

______________________________________________________________

______________________________________________________________

______________________________________________________________

(2)

(iii) Explain how the change in blood flow to the athlete’s muscles helps him to run.

______________________________________________________________

______________________________________________________________

______________________________________________________________

28

______________________________________________________________

______________________________________________________________

______________________________________________________________

______________________________________________________________

______________________________________________________________

______________________________________________________________

______________________________________________________________

(4)

(Total 9 marks)

Q9. Malaria is a disease caused by a microorganism carried by mosquitoes.

The microorganism is transferred to humans when adult female mosquitoes feed on human blood.

The figure below shows the life cycle of a mosquito.

© watcharapon/iStock

The World Health Organisation estimates that 3 × 108 people are infected with malaria every

year.

Scientists estimate that malaria kills 2 × 106 people every year.

The people who are infected with malaria but do not die, may be seriously ill and need health care

for the rest of their lives.

29

(a) Based on the estimated figures, what percentage of people infected with malaria die from

the disease?

___________________________________________________________________

___________________________________________________________________

___________________________________________________________________

___________________________________________________________________

(2)

(b) An internet article states:

1 Mosquito larvae are at the start of the food chain for some fish.

2 Adult mosquitoes provide food for bats and birds.

3 Mosquitoes are also important in plant reproduction because they feed from flowers

of crop plants.

(i) The first sentence in the article is not correct.

Explain why.

______________________________________________________________

______________________________________________________________

______________________________________________________________

______________________________________________________________

(2)

(ii) A company plans to produce genetically modified (GM) adult male mosquitoes.

The GM mosquitoes will carry a gene from bacteria. The gene causes the death of

offspring before they become adults.

Male mosquitoes do not feed on blood.

Scientists are considering releasing millions of adult male GM mosquitoes into the

wild.

Do you think scientists should release millions of male GM mosquitoes into the wild?

In your answer you should give advantages and disadvantages of releasing GM

mosquitoes into the wild.

______________________________________________________________

______________________________________________________________

______________________________________________________________

______________________________________________________________

______________________________________________________________

______________________________________________________________

______________________________________________________________

______________________________________________________________

30

(4)

(iii) Describe the process for creating a GM mosquito.

______________________________________________________________

______________________________________________________________

______________________________________________________________

______________________________________________________________

______________________________________________________________

______________________________________________________________

(3)

(Total 11 marks)

Q10. Some students investigated the size of a population of dandelion plants in a field.

The diagram below shows the field.

The students:

• placed a 1 m × 1 m square quadrat at 10 random positions in the field

• counted the number of dandelion plants in each quadrat.

The table below shows the students’ results.

Quadrat

number

Number of

dandelion plants

1 6

2 9

31

3 5

4 8

5 0

6 10

7 2

8 1

9 8

10 11

(a) Why did the students place the quadrats at random positions?

___________________________________________________________________

___________________________________________________________________

(1)

(b) Estimate the total number of dandelion plants in the field.

Calculate your answer using information from the diagram and the table above.

Give your answer in standard form.

___________________________________________________________________

___________________________________________________________________

___________________________________________________________________

___________________________________________________________________

___________________________________________________________________

___________________________________________________________________

___________________________________________________________________

___________________________________________________________________

___________________________________________________________________

___________________________________________________________________

Total number of dandelion plants = ____________________

(5)

Quadrats 5, 7 and 8 were each placed less than 10 metres from the woodland.

These quadrats contained low numbers of dandelion plants.

The students made the hypothesis:

‘Light intensity affects the number of dandelion plants that grow in an area.’

32

(c) Plan an investigation to test this hypothesis.

___________________________________________________________________

___________________________________________________________________

___________________________________________________________________

___________________________________________________________________

___________________________________________________________________

___________________________________________________________________

___________________________________________________________________

___________________________________________________________________

___________________________________________________________________

___________________________________________________________________

___________________________________________________________________

___________________________________________________________________

___________________________________________________________________

___________________________________________________________________

___________________________________________________________________

___________________________________________________________________

___________________________________________________________________

___________________________________________________________________

___________________________________________________________________

___________________________________________________________________

(6)

(d) Light is an environmental factor that affects the growth of dandelion plants.

Give two other environmental factors that affect the growth of dandelion plants.

1. _________________________________________________________________

2. _________________________________________________________________

(2)

(Total 14 marks)

Q11. Table 1 shows information about some food components in cow’s milk.

Table 1

33

Value per

500 cm3

Recommended Daily

Allowance (RDA) for

a typical adult

Energy in kJ 1046 8700

Fat in g 8.4 70.0

Salt in g 0.5 6.0

Calcium in mg 605 1000

Vitamin B-12 in µg 4.5 2.4

(a) How much more milk would a typical adult have to drink to get their RDA for calcium

compared with the amount of milk needed to get their RDA for vitamin B-12?

___________________________________________________________________

___________________________________________________________________

___________________________________________________________________

___________________________________________________________________

___________________________________________________________________

___________________________________________________________________

Volume of milk = ______________________ cm3

(3)

(b) Describe how a student could test cow’s milk to show whether it contains protein and

different types of carbohydrate.

___________________________________________________________________

___________________________________________________________________

___________________________________________________________________

___________________________________________________________________

___________________________________________________________________

___________________________________________________________________

___________________________________________________________________

___________________________________________________________________

___________________________________________________________________

___________________________________________________________________

___________________________________________________________________

___________________________________________________________________

___________________________________________________________________

34

___________________________________________________________________

___________________________________________________________________

___________________________________________________________________

___________________________________________________________________

___________________________________________________________________

(6)

A scientist investigated the effect of bile on the breakdown of fat in a sample of milk.

The scientist used an indicator that is colourless in solutions with a pH lower than 10, and pink in

solutions with a pH above 10.

This is the method used.

1. Add 1 drop of bile to a test tube and one drop of water to a second test tube.

2. Add the following to each test tube:

• 5 cm3 of milk

• 7 cm3 of sodium carbonate solution (to make the solution above pH 10)

• 5 drops of the indicator

• 1 cm3 of lipase.

3. Time how long it takes for the indicator in the solutions to become colourless.

The results are shown in Table 2.

Table 2

Time taken for the indicator to

become colourless in seconds

Solution with bile 65

Solution without bile 143

(c) Explain why the indicator in both tubes became colourless.

___________________________________________________________________

___________________________________________________________________

___________________________________________________________________

___________________________________________________________________

___________________________________________________________________

___________________________________________________________________

(3)

(d) Give the reason why the measurement of the time taken for the indicator to become

colourless might be inaccurate.

___________________________________________________________________

35

___________________________________________________________________

(1)

(e) Explain the difference in the results for the two test tubes in Table 2.

___________________________________________________________________

___________________________________________________________________

___________________________________________________________________

___________________________________________________________________

___________________________________________________________________

___________________________________________________________________

(3)

(Total 16 marks)

Q12. Catalase is an enzyme found in many different tissues in plants and animals. It speeds up the rate

of the following reaction.

hydrogen peroxide water + oxygen

Figure 1 shows a 25-day-old broad bean seedling.

Some students investigated whether different parts of bean seedlings contained different amounts

of catalase.

The students:

• put hydrogen peroxide into five test tubes

• added a different part of a bean seedling to each tube

• recorded the results after half a minute.

If there was catalase in part of the seedling, oxygen gas was given off.

When oxygen gas is given off, foam is produced in the tubes.

Figure 2 shows the results.

36

The students made the following conclusions:

• most parts of a bean seedling contain catalase

• the seed contains a lot of catalase

• stems and roots have quite a lot of catalase

• the leaves have a little bit of catalase

• the seed coat has hardly any catalase.

The students’ teacher said that the students needed to improve their investigation in order to

make valid conclusions.

(a) In this question you will be assessed on using good English, organising

information clearly and using specialist terms where appropriate.

Describe how you would carry out an investigation to compare the amounts of catalase in

different parts of bean seedlings.

You should include details of how you would make sure your results give a valid

comparison of the amounts of catalase.

___________________________________________________________________

___________________________________________________________________

___________________________________________________________________

___________________________________________________________________

___________________________________________________________________

___________________________________________________________________

___________________________________________________________________

___________________________________________________________________

___________________________________________________________________

37

___________________________________________________________________

(6)

(b) Scientists investigated the effect of pH on the activity of the enzyme catalase in a fungus.

The table below shows the scientists’ results.

pH

Enzyme activity in arbitrary units

Test 1 Test 2 Test 3 Test 4 Test 5 Mean

3.0 0 0 0 0 0 0

4.0 6 5 8 4 7 6

5.0 38 65 41 42 39

5.5 80 86 82 84 88 84

6.0 100 99 96 103 102 100

6.5 94 92 90 93 91 92

7.0 61 63 61 62 63 62

8.0 22 22 21 24 21 22

(i) Calculate the mean enzyme activity at pH 5.0.

______________________________________________________________

______________________________________________________________

Mean = _____________ arbitrary units

(2)

(ii) On the graph paper in Figure 3, draw a graph to show the scientists’ results.

Remember to:

• add a label to the vertical axis

• plot the mean values of enzyme activity

• draw a line of best fit.

Figure 3

38

(4)

(iii) At what pH does the enzyme work best?

____________________

(1)

(iv) Predict the activity of the enzyme at pH 9.0.

____________________ arbitrary units

(1)

(v) Suggest why the enzyme’s activity at pH 3.0 is zero.

______________________________________________________________

______________________________________________________________

(1)

(Total 15 marks)

Q13. During exercise, the heart beats faster and with greater force.

The ‘heart rate’ is the number of times the heart beats each minute.The volume of blood that

travels out of the heart each time the heart beats is called the ‘stroke volume’.

In an investigation, Person 1 and Person 2 ran as fast as they could for 1 minute. Scientists

measured the heart rates and stroke volumes of Person 1 and Person 2 at rest, during the

exercise and after the exercise.

39

The graph below shows the scientists’ results.

(a) The ‘cardiac output’ is the volume of blood sent from the heart to the muscles each minute.

Cardiac output = Heart rate × Stroke volume

At the end of the exercise, Person 1’s cardiac output = 160 × 77 = 12 320 cm3 per

minute.

Use information from the figure above to complete the following calculation of Person 2’s

cardiac output at the end of the exercise.

At the end of the exercise:

Person 2’s heart rate = _______________ beats per minute

Person 2’s stroke volume = _______________ cm3

Person 2’s cardiac output = _______________ cm3 per minute

(3)

(b) Person 2 had a much lower cardiac output than Person 1.

(i) Use information from the figure above to suggest the main reason for the lower

cardiac output of Person 2.

______________________________________________________________

______________________________________________________________

(1)

(ii) Person 1 was able to run much faster than Person 2.

40

Use information from the figure above and your own knowledge to explain why.

______________________________________________________________

______________________________________________________________

______________________________________________________________

______________________________________________________________

______________________________________________________________

______________________________________________________________

______________________________________________________________

______________________________________________________________

______________________________________________________________

______________________________________________________________

(5)

(Total 9 marks)

41

41

Summer Work Mark Schemes

Q1.

(a) any one from:

• respiration

• formation of proteins

• formation / breakdown of glycogen

• breakdown of (excess) protein or formation of urea

• photosynthesis or formation of glucose / starch (in plants)

ignore formation of carbohydrates

1

allow other correct reference to metabolic reactions in

cells

ignore reference to digestion

(b) males have a higher metabolic rate than females after five years of age

1

the mean metabolic rate of females decreases faster than males up to 25 years of

age

1

each additional tick negates a mark

(c)

1

32.075472…

allow correct rounding of this to at least 4 significant

figures

1

32.1

allow a correct reduction to 3 significant figures from an

incorrect calculation for marking point 2

1

an answer of 32.1 scores 3 marks

(d) any two from:

allow converse

• (person) R heart rate rose / increased more slowly than (person) S

• (person) R heart rate levelled off whereas (person) S continued to increase

• (person) R heart rate rose less (overall / after 5 minutes of exercise) than S

allow correct use of figures

e.g. R increased (overall) by 39 bpm / 65% and S by 54

bpm / 69%

ignore lack of units

2

(e) correct scale and axis labelled

allow min(s)

42

do not accept ‘m’

the zero is not required on the x-axis

1

all points plotted correctly (to within ± ½ square)

allow 4 or 5 correct plots for 1 mark

2

line joined point to point or correct curved line of best fit

1

(f)

allow sequential deductions of 12 four or five times

1

4.5 (minutes) / 4½ minutes / 4 minutes 30 seconds / 4:30

do not accept 4:50 or 4 minutes 50 seconds

1

an answer of 4.5 minutes scores 2 marks

(g) Level 3: The method would lead to the production of a valid outcome. All key

steps are identified and logically sequenced.

5−6

Level 2: The method would not necessarily lead to a valid outcome. Most steps

are identified, but the method is not fully logically sequenced.

3−4

Level 1: The method would not lead to a valid outcome. Some relevant steps are

identified, but links are not made clear.

1−2

No relevant content

0

Indicative content

• two groups of people − non-smokers and smokers

• have at least five people in each group or large groups

• get each person to do (named) exercise

• controlled variables:

− same number of people in each group or large groups

− same gender

− same level of activity / exercise

− same age

− no health issues / illnesses

− same type of exercise

− same time for exercise

• record heart rate for each person before and after exercise

• calculate increase in heart rate for each person after exercise

• compare results for each group

43

for level 3, students should refer to at least 5 smokers and 5 non-smokers,

carrying out exercise with control variables and a means of determining an increase

in heart rate

for level 2, students should refer to ‘groups’ of smokers and non-smokers

exercising

[20]

Q2.

(a) 860

correct answer gains 2 marks

if answer incorrect evidence of (6100 - 1800) ÷ 5

or 4300 ÷ 5

or (900 + 600 + 1000 + 700 + 1100) ÷ 5 gains 1 mark

allow ecf from 1 incorrect graph reading

2

(b) ignore references to oxygen / sulfur dioxide / nitrogen oxides / acid rain

ignore global warming

Effects of deforestation

deforestation increases the amount of carbon dioxide in the atmosphere

award this point only if linked to deforestation

1

any two from:

• due to less photosynthesis or less carbon dioxide taken in

or carbon dioxide not locked up in (forest) trees

• due to burning of forest / from machinery

• due to activity of microorganisms / decay

2

Effects of growing palm for fuel

carbon dioxide released when palm oil used as fuel

1

(eventually) CO2 intake and output might balance out or burning palm

oil carbon neutral

accept less carbon dioxide than from burning fossil fuels

1

[7]

Q3.

(a) (i) 8.6

accept value in range 8.5 to 8.7

1

(ii) hydrochloric acid / HCl

accept HCL

44

accept hydrogen chloride

ignore hcl / etc.

1

(iii) X

1

(b) Marks awarded for this answer will be determined by the Quality of Written

Communication (QWC) as well as the standard of the scientific response.

Examiners should also refer to the information in the Marking guidance.

0 marks

No relevant content.

Level 1 (1-2 marks)

There is a simple description of part of a process or a reference to at least one of:

mechanical digestion, lipase, product of enzyme action, bile, site of production or

site of digestion

Level 2 (3-4 marks)

There is a description of at least one process linking ideas

Level 3 (5-6 marks)

There is a clear description of the process including reference to the majority of:

mechanical digestion, lipase, bile, where they are produced, products, function of

bile and site of digestion / absorption

Examples of biological points made in the response:

• mechanical breakdown in mouth / stomach

• fats →fatty acids and / or glycerol

• by lipase

• (produced by) pancreas

• and small intestine

• fat digestion occurs in small intestine

• bile

• produced by liver

• neutralises acid from stomach

• produces alkaline conditions in intestine

• refs. to increased surface area related to emulsification or chewing

• products are small molecules / water-soluble

• products absorbed by small intestine

6

[9]

45

Q4.

(a) Marks awarded for this answer will be determined by the Quality of Communication

(QC) as well as the standard of the scientific response. Examiners should also refer to the

information on page 5, and apply a ‘best − fit’ approach to the marking.

0 marks

No relevant content.

Level 1 (1 − 2 marks)

The method described is weak and could not be used to collect valid results

however does show some understanding of the sequence of an investigation.

Level 2 (3 − 4 marks)

The method described could be followed and would enable some results to be

collected but lacks detail.

Level 3 (5 − 6 marks)

The method described could be easily followed and would enable valid results to

be collected.

examples of biology points made in the response:

• (use of measuring cylinder to) measure equal volumes of detergent solution

• (use of dropping bottle to) apply same number of drops / amount of stain to each

piece of cloth

• include stainless cloth as control

• use of forceps to transfer cloths

• use of test tubes as containers for detergent solution + stained cloth

• use water bath to provide a range of temperatures

• cloths left in detergent solution at each temperature

• for same length of time or measure time taken to remove stain

• repetition

• assessing the stain removal

6

(b) (i) y axis: labelled ‘Time (taken to remove stain in) minutes’ plus suitable scale

data spread greater than half of grid

1

points or bars plotted correctly to within ± 1 mm

deduct 1 mark for each incorrect plot up to a maximum of 2

2

one suitable line of best fit drawn on graph

not feathery

not extrapolated to (0,0)

not point to point as on this occasion it is inappropriate

1

(ii) 6 ± 0.1

accept ecf from student graph

1

(c) activity of enzyme still very high / 84% / over 80%

or

46

only lost 15% / 16% activity

allow above 60 °C marked decrease in activity

allow 85%

1

any two from:

• rate of reaction high at 60 °C / higher than at lower temperatures

allow in terms of reaction kinetics / collisions

• higher temperatures would increase (energy) costs

or

might damage cloth

ignore enzyme denaturation

• higher temperatures / 60 °C is better (than lower temperatures) to remove other

stains / named stains

or

better for killing bacteria / infection control

eg grease

2

[14]

Q5.

(a) (i) 1 hour 15 mins / 1.25 hours / 75 mins

allow 1:15

ignore 1.15 hours

1

(ii) increase in (core / body) temperature

ignore numbers

1

(due to an) increase in respiration or more muscle contraction

1

releasing energy (as a waste product)

allow produces ‘heat’

do not allow making energy

1

skin temperature decreases

1

(because there is) sweating

1

(which) evaporates and cools the skin

ignore references to vasodilation or vasoconstriction

1

(iii) (there is) dilation of vessels (supplying skin capillaries)

allow vasodilation

allow blood vessels widen

47

ignore expand

do not accept dilating capillaries or moving vessels

1

(so) more blood flows (near skin) (surface) or blood is closer (to the skin)

ignore ref to heat

1

(c) pancreas detects (low) blood glucose

1

produces glucagon

do not allow glucagon made in the liver

1

(so) glycogen is converted to glucose

allow adrenaline released which increases conversion of glycogen to

glucose

or

reduced insulin production so less glucose into cells / less glucose

converted to glycogen

for 1 mark

1

[12]

Q6.

(a) (the kidney) filters the blood

ignore refs to hormones and drugs

1

(and then) reabsorbs all of the glucose

1

reabsorbs some of the ions

allow salts

ignore minerals

1

reabsorbs some of the water

1

releases urea (in urine)

1

(b) (i) should fall from 28 (to the end of dialysis)

ignore any line drawn after end of dialysis

allow + / - 0.5 square

graph line must fall to / below

below 15

1

(ii) should stay level at about 6 throughout

ignore slight variations

48

allow + / - 1 square

ignore any line drawn after end of dialysis

1

(c) (i) immune system

allow white blood cells / lymphocytes

1

(produces) antibodies

1

(which) attack the antigens (on the transplanted kidney)

non-matching antigens insufficient

1

(ii) any one from:

• tissue typing (to find match)

• treating with drugs that suppress the immune system

accept treat with immunosuppressants.

1

[11]

Q7.

(a) wear a face mask

allow wear gloves

1

(b) Level 2 (3–4 marks):

A detailed and coherent plan covering all the major steps. It sets out the steps needed in

a logical manner that could be followed by another person to produce an outcome which

will address the hypothesis.

Level 1 (1–2 marks):

Simple statements relating to steps are made but they may not be in a logical order. The

plan may not allow another person to produce an outcome which will address the

hypothesis.

0 marks:

No relevant content.

Indicative content

Plan:

• cut a specified number of pieces of bread to the same size

• place mould spores on the bread

• the number of mould spores needs to be the same quantity of mould spores on

each piece of bread

• place bread in different sealable plastic bags

• place in different temperatures (minimum of three) eg fridge, room, incubator

• leave each for the same amount of time eg four days

• measure the percentage cover of mould on each piece of bread

• repeat experiment

additional examiner guidance:

• good level 2 answer will describe how the growth of mould can be measured and

49

will give a range of different temperatures to be used

• allow equivalent levels of credit for alternative methodologies that would clearly

produce a measurable outcome in terms of mould growth at various temperatures

4

(c) any one from:

• type of mould

• amount of mould (put on each piece of bread)

• amount of air in the plastic bags

• size of the pieces of bread

• type of bread

• amount of moisture / water added

1

(d) (56 − 4 = 52) / 5

1

10.4

allow 10.4 with no working shown for 2 marks

1

ecf for incorrectly read figures for 1 mark

(e) (decomposition occurs at a faster rate when the temperature is higher

or

amount of decomposition is higher when temperature is higher

1

[9]

Q8.

(a) (i) without oxygen

allow not enough oxygen

ignore air

ignore production of CO2

ignore energy

1

(ii) more / high / increased lactic acid (at end)

allow approximate figures (to show increase)

ignore reference to glucose

1

(b) (i) 1.5

allow only 1.5 / 1½ / one and a half

1

(ii) increases at first and levels off

ignore subsequent decrease

1

suitable use of numbers eg

rises to 10 / by 9 (dm3 per min)

or

increases up to 1.5 (min) / levels off after 1.5 (min) (of x axis timescale)

allow answer in range 1.4 to 1.5

50

or

after the first minute (of the run)

1

(iii) supplies (more) oxygen

1

supplies (more) glucose

1

need ‘more/faster’ once only for full marks

allow removes (more) CO2 / lactic acid / heat as an alternative for

either marking point one or two, once only

for (more) respiration

1

releases (more) energy (for muscle contraction)

do not allow energy production or for respiration

1

[9]

Q9.

(a) 0.67(%)

allow

allow 1 mark for evidence of (2 × 106) ÷ (3 × 108)

or

allow 1 mark for 0.0067 or 0.6

2

(b) (i) idea that food chains start with plants / producers

allow food chains do not start with animals or larvae are consumers

1

idea that these make food (for other organisms in the chain)

allow idea that plants / producers photosynthesise or plants /

producers get energy from the sun

allow mosquito larvae do not make food / photosynthesise or

mosquito larvae do not get energy from the sun

1

(ii) any four from:

• reasoned argument for or against release

must refer to at least one advantage and one disadvantage.

max 3 marks for either only advantages or only disadvantages

advantages:

• fewer mosquitos biting or spreading malaria

• fewer people get / die from malaria

allow people won’t get / die from malaria

• lower medical costs (for those infected or for treatment) or less healthcare

needed

• better economically for developing / tropical countries.

disadvantages:

• fewer crops reproduce

51

allow fewer crops pollinated

• poorer crop yield

• possible starvation (of people)

• high cost of GM production / mosquito release

• less food for bats / birds or bats / birds die

allow disruption to food chain / ecosystem or reduction of biodiversity

• gene could ‘escape’ into other wildlife / species

ignore into plants

4

(iii) any three from:

• gene from bacteria cut out

allow allele for gene

• ref to enzymes (anywhere in process)

allow at any point in process, ie in cutting or in splicing

• (gene) transferred to chromosome of mosquito

allow DNA for chromosome

• at an early stage of development

allow egg / embryo

3

[11]

Q10.

(a) there is an uneven distribution of dandelions

or

(more) representative / valid

or

avoid bias

or

more accurate / precise mean

ignore accurate / precise unqualified

ignore repeatability / reproducibility / reliability / fair test

1

(b) (correct mean per m2 =) 6 or 6.0

1

(correct field area =) 55 000 (m2)

1

mean × area − e.g. 6(.0) × 55 000

allow incorrect calculated values for mean and / or field

area

1

330 000

allow correct calculation from previous calculation

1

3.3 × 105

allow calculated value in standard form

1

an answer of 3.3 × 105 scores 5 marks

an answer of 330 000 scores 4 marks

52

(c) Level 3: The method would lead to the production of a valid outcome. All key

steps are identified and logically sequenced.

5−6

Level 2: The method would not necessarily lead to a valid outcome. Most steps

are identified, but the method is not fully logically sequenced.

3−4

Level 1: The method would not lead to a valid outcome. Some relevant steps are

identified, but links are not made clear.

1−2

No relevant content

0

Indicative content

• placing of quadrat

• large number of quadrats used

• how randomness achieved − e.g. table of random numbers or random

number button on calculator or along transect

• quadrats placed at coordinates or regular intervals along transect

• in each of two areas of different light intensities or transect running through

areas of different light intensity

• for each quadrat count number of dandelions

• for each quadrat measure light intensity

• compare data from different light intensity

to access level 3 the key ideas of using a large number of quadrats randomly, or

along a transect, and counting the number of dandelions in areas of differing light

intensity need to be given to produce a valid outcome

(d) any two from:

• temperature

allow heat

• water

allow moisture / rain

• (soil) pH

allow acidity

• minerals / ions

allow e.g. magnesium ions or nitrate

allow salts / nutrients

• winds

• herbivores

allow trampling

ignore carbon dioxide

ignore space

ignore competition unqualified

do not accept oxygen

2

[14]

53

Q11.

(a) (for calcium)

allow any correct rounding to minimum 3 significant

figures

allow alternative route with correct rounding

1

(for vitamin B-12)

allow alternative route with correct rounding

1

560 / 559.8 / 559.78 / 559 (cm3)

allow only correct answer based on values given for

vitamin B-12 and calcium

1

an answer of 560 / 559.8 / 559.78 / 559 (cm3) scores

3 marks

an incorrect answer for one step does not prevent

allocation of marks for subsequent steps

(b) Level 2: Scientifically relevant facts, events or processes are identified and given in

detail to form an accurate account.

4−6

Level 1: Facts, events or processes are identified and simply stated but their

relevance is not clear.

1−3

No relevant content

0

Indicative content

• Biuret reagent (allow CuSO4 and NaOH) tests for protein

• add Biuret reagent to milk

• solution will turn (from blue) to lilac if positive

• iodine solution tests for starch (ignore iodine unqualified)

• add iodine solution to milk

• solution will turn (from orange / brown) to blue / black if positive

• Benedict’s reagent tests for sugars

• add Benedict’s reagent to milk and boil / heat (allow any temperature above 60 °C)

• solution will turn (from blue) to (brick) red / brown / orange / yellow / green if

positive

for level 2, reference to all three food tests is required

(c) lipase breaks down fat into fatty acids (and glycerol)

54

do not accept if ‘glycerol’ is contradicted

1

(and) fatty acids lower the pH

1

(and when) fatty acids cause the pH to be below 10 (the indicator becomes

colourless)

1

(d) observation of colour change is subjective / based on opinion

ignore human error unqualified

ignore experimental error or examples of this

1

(e) bile emulsifies fats

allow a correct description of emulsification (i.e. breaks

fat from large droplets into smaller droplets)

do not accept a description of chemical breakdown

1

creates a larger surface area (of fat)

1

(so) lipase can break down fat (to produce fatty acids) more quickly / effectively

allow fatty acids produced by action of lipase more

quickly

1

[16]

Q12.

(a) Marks awarded for this answer will be determined by the Quality of Communication

(QC) as well as the standard of the scientific response. Examiners should also refer to the

information in the Marking guidance and apply a ‘best-fit’ approach to the marking.

0 marks

No relevant content.

Level 1 (1−2 marks)

The method described is weak and could not be used to collect valid results,

however does show some understanding of the sequence of an investigation.

Level 2 (3−4 marks)

The method described could be followed and would enable some valid results to

be collected, but lacks detail.

Level 3 (5−6 marks)

The method described could be easily followed and would enable valid results to

be collected.

Examples of the points made in the response:

• bean seedlings of same age

• cut material from same part of each organ (for repeats) e.g. top 1 cm of

stem / a whole cotyledon / seed

• equal mass of each organ

55

accept weight for mass

• grind / homogenise

• in equal amounts of water / buffer

• equal volumes of hydrogen peroxide solution

• equal concentrations of hydrogen peroxide solution

• same temperature

• temperature maintained in water bath

• quantitative measure of gas production eg height of foam in mm / collect gas

in graduated syringe in cm3

• for same time period

• repetitions (3+ times)

• calculate mean for each.

6

(b) (i) correct answer: 40

1 mark for 45 as the anomalous result has been included in the

calculation

or

1 mark for

or

2

(ii) vertical axis correctly labelled:

‘Enzyme activity in arbitrary units’

allow ecf from (b)(i)

1

points plotted correctly ±1 mm

deduct 1 mark for each incorrect plot

2

suitable line of best fit

not feathery, not point to point

1

(iii) 6.0 / 6

allow ± 0.1

if 6.0 not given, allow correct for candidate’s graph ± 0.1

1

(iv) in range 0 to 14 units

allow correct for candidate’s graph

1

(v) enzyme denatured / enzyme (active site) shape changed

allow substrate no longer fits (active site)

ignore reference to temperature

do not allow enzyme dies

1

[15]

56

Q13.

(a) 5624

allow 2 marks for:

• correct HR = 148 and correct SV = 38 plus wrong answer /

no answer

or

• only one value correct and ecf for answer

allow 1 mark for:

• incorrect values and ecf for answer

or

• only one value correct

3

(b) (i) Person 2 has low(er) stroke volume / SV / described

eg Person 2 pumps out smaller volume each beat

do not allow Person 2 has lower heart rate

1

(ii) Person 1 sends more blood (to muscles / body / lungs)

1

(which) supplies (more) oxygen

1

(and) supplies (more) glucose

1

(faster rate of) respiration or transfers (more) energy for use

ignore aerobic / anaerobic

allow (more) energy release

allow aerobic respiration transfers / releases more energy (than

anaerobic)

do not allow makes (more) energy

1

removes (more) CO2 / lactic acid / heat

allow less oxygen debt

or less lactic acid made

or (more) muscle contraction / less muscle fatigue

if no other mark awarded,

allow person 1 is fitter (than person 2) for max 1 mark

1