4.5 Homeostasis and Response Foundation / Higher

4.5 Homeostasis and Response

Foundation / Higher

Name:

________________________

Class:

________________________

Date:

________________________

Time:

278 minutes

Marks:

272 marks

Comments:

Q1.

Diagrams A, B and C show cells from different parts of the human body, all drawn to the

same scale.

(a) Which cell, A, B or C, appears to have adaptations to increase diffusion into or out

of

the cell?

Give one reason for your choice.

___________________________________________________________________

(1)

(b) (i) Cell C is found in the pancreas.

Name one useful substance produced by the pancreas.

______________________________________________________________

(1)

(ii) Use information from the diagram to explain how cell C is adapted for

producing this substance.

______________________________________________________________

(2)

(Total 4 marks)

Q2.

Diabetes is a disease in which a person‟s blood glucose concentration rises to higher

levels than normal.

Diabetes is caused by insufficient insulin being produced.

(a) (i) Which organ monitors blood glucose concentration?

______________________________________________________________

(1)

(ii) Insulin reduces the concentration of glucose in the blood.

Describe how insulin does this.

______________________________________________________________

(1)

(b) A person with diabetes can be monitored in three ways:

• measuring the blood glucose concentration after fasting (going without food

for 12 hours)

• measuring the amount of glucose attached to red blood cells: this is a

measure of the average blood glucose concentration over the previous three

months

• measuring the concentration of insulin in the blood after fasting

The manufacturer of a new treatment for diabetes, called Diacure, publishes the

following two claims.

1. 98.6% of all people who used Diacure reported an improvement in their condition.

2. An independent study of 30 diabetic patients showed a significant reduction in blood

glucose concentrations and a significant increase in insulin production, as shown by

the graph.

(i) Which of the manufacturer‟s claims is not based on scientific evidence?

______________________________________________________________

(1)

(ii) Why might the data in this study be unreliable?

______________________________________________________________

(1)

(iii) The manufacturer did not draw attention to the data for the amount of glucose

attached to red blood cells.

Suggest an explanation for this.

______________________________________________________________

(2)

(iv) The study of diabetic patients was carried out by an independent company.

Why is it important that the study should be independent?

______________________________________________________________

(1)

(Total 7 marks)

Q3.

(a) (i) Where are hormones produced?

______________________________________________________________

(1)

(ii) How do hormones move around the body?

______________________________________________________________

(1)

(b) Insulin is a hormone.

(i) Where is insulin produced?

______________________________________________________________

(1)

(ii) Explain the role of insulin in controlling blood sugar levels.

______________________________________________________________

(4)

(Total 7 marks)

Q4.

The diagram shows part of the human digestive system.

(i) Name part B.

___________________________________________________________________

(1)

(ii) Describe the role of B and D in reducing blood sugar levels.

___________________________________________________________________

(2)

(Total 3 marks)

Q5.

The diagram shows a reflex pathway in a human.

(a) Label the receptor on the diagram.

(1)

(b) Label the effector on the diagram.

(1)

(c) (i) Suggest a stimulus to the hand that could start a reflex response.

______________________________________________________________

(1)

(ii) Describe the response that this stimulus would cause. ___________________

______________________________________________________________

(1)

(d) Put arrows on the diagram to show the direction of the path taken by the nerve

impulses.

(1)

(Total 5 marks)

Q6.

(a) During respiration, sugar is oxidised to release energy. Complete the equation for

respiration.

Sugar + ______________ = ______________ + ______________ + energy

(3)

(b) The photograph below shows an athlete using an exercise machine. The machine

can be adjusted to vary the rate at which the athlete is required to work.

The athlete‟s heart rate and breathing rate were measured at different work rates.

The table below shows the results which were obtained.

WORK RATE

(J/s)

HEART RATE

(beats/min.)

BREATHING RATE

(breaths/min.)

0

86

9.6

60

106

10.0

80

112

10.4

100

122

10.4

120

135

11.4

140

143

14.5

160

156

15.8

200

174

30.5

Plot the data on the graph paper below.

(3)

(c) Explain, as fully as you can, the advantages to the body in the change in breathing

and heart rates.

___________________________________________________________________

(6)

(d) This increase in the rate of heart-beat is a response to a stimulus. For this response

suggest:

(i) the stimulus; _____________________________________________

(ii) the co-ordinator; _____________________________________________

(iii) the effector. _____________________________________________

(3)

(Total 15 marks)

Q7.

The internal body temperature determines how much a person sweats. The graph shows

the effect of different internal body temperatures on a person‟s rate of energy loss by

sweating.

(a) How much more energy was lost from the body each second by sweating when the

body temperature was 37.6 °C than when it was 36.6 °C? Show clearly how you

work out your final answer.

___________________________________________________________________

Amount of energy = ________________ joules per second

(2)

(b) Explain why a person would feel more thirsty when the body temperature was 37.6

°C than when it was 36.6 °C.

___________________________________________________________________

(2)

(c) Explain how sweating helps to control body temperature.

___________________________________________________________________

(3)

(Total 7 marks)

Q8.

Hormones are sometimes used to regulate human reproduction.

(a) (i) What is a hormone?

______________________________________________________________

(1)

(ii) How are hormones transported around the body?

______________________________________________________________

(1)

(b) Describe the benefits and possible problems that may result from the use of

hormones to regulate human reproduction. You should refer to fertility drugs and

contraceptives in your answer.

To gain full marks in this question you should write your ideas in good English. Put

them into a sensible order and use the correct scientific words.

___________________________________________________________________

(4)

(Total 6 marks)

Q9.

The pancreas is involved in digestion and controlling the internal conditions of the body.

(a) Name two digestive enzymes produced by the pancreas.

1. _________________________________________________________________

2. _________________________________________________________________

(2)

(b) Diabetes may be caused by a lack of insulin.

Part of the treatment for someone with diabetes is to pay careful attention to the

diet.

(i) Give one symptom of diabetes.

______________________________________________________________

(1)

(ii) Give one way in which a diabetic may be advised to change their diet.

______________________________________________________________

(1)

(iii) How does this change in diet help the diabetic?

______________________________________________________________

(1)

(iv) State one other way in which the symptoms of diabetes may be treated.

______________________________________________________________

(1)

(c) Many of the cells in the pancreas contain large numbers of ribosomes.

What is the function of ribosomes in a cell?

___________________________________________________________________

(1)

(Total 7 marks)

Q10.

The graph shows the concentration of glucose in the blood of two people. Person A is a

non-diabetic. Person B has diabetes. Each person ate 75 grams of glucose at 1.0 hours.

(a) (i) What was the maximum concentration of glucose in the blood of Person A?

_________________________________ mmol per dm

3

(1)

(ii) After eating the glucose, how long did it take for the concentration of glucose

in the blood of Person B to return to normal?

________________________________________ hours

(1)

(b) A diabetic person does not produce enough insulin.

(i) Which organ produces insulin?

______________________________________________________________

(1)

(ii) Write the letter X on the graph to show one time when the blood of Person A

would contain large amounts of insulin.

(1)

(c) A high concentration of glucose in the blood can harm body cells as a result of

osmosis.

Explain why.

______________________________________________________________

(4)

(Total 8 marks)

Q11.

Reflex actions are rapid and automatic.

(a) Name the following structures in a reflex action.

(i) The structure that detects the stimulus.

______________________________________________________________

(1)

(ii) The neurone that carries impulses to the central nervous system.

______________________________________________________________

(1)

(iii) The neurone that carries impulses away from the central nervous system.

______________________________________________________________

(1)

(iv) The structure that brings about the response.

______________________________________________________________

(1)

(b) Describe what happens at a synapse when an impulse arrives.

___________________________________________________________________

(2)

(c) Some people have a condition in which information from the skin does not reach the

brain.

Explain why this is dangerous for the person.

___________________________________________________________________

(2)

(Total 8 marks)

Q12.

In diabetics blood glucose concentrations are sometimes abnormal.

(a) Name the organ that monitors the concentration of glucose in the blood.

___________________________________________________________________

(1)

(b) Diabetics can measure their blood glucose concentration.

The graph shows the best blood glucose concentration and the acceptable range of

blood glucose concentration at different times.

What is the acceptable range for the blood glucose concentration before meals?

From _________________________ to _________________________ mmol per

dm

3

(1)

(c) The amount of insulin a diabetic injects can be changed so that blood glucose

concentration is kept near to the best level.

Two hours after eating breakfast a diabetic measures his blood glucose

concentration.

His blood glucose concentration is 13 mmol per dm

3

.

He reads these instructions:

• for every 2 mmol per dm

3

of blood glucose above the best concentration, inject

1 unit more of insulin

• for every 2 mmol per dm

3

of blood glucose below the best concentration, inject

1 unit less of insulin.

How should he change his normal insulin injection to bring his blood glucose level to

the best concentration?

Show clearly how you work out your answer.

___________________________________________________________________

Answer = _______________________________________

(3)

(Total 5 marks)

Q13.

The human body produces many hormones.

(a) (i) What is a hormone?

______________________________________________________________

(1)

(ii) Name an organ that produces a hormone.

______________________________________________________________

(1)

(iii) How are hormones transported to their target organs?

______________________________________________________________

(1)

(b) Describe how the hormones FSH, oestrogen and LH are involved in the control of

the menstrual cycle.

___________________________________________________________________

(3)

(Total 6 marks)

Q14.

It is important that the concentration of glucose (sugar) in the blood is controlled.

(a) (i) Which hormone controls the concentration of glucose in the blood?

______________________________________________________________

(1)

(ii) Which organ produces this hormone?

______________________________________________________________

(1)

(b) The concentration of glucose in the blood of two people, A and B, was measured

every half an hour.

One hour after the start, both people drank a solution containing 50 g of glucose.

The graph shows the result.

(i) By how much did the blood glucose concentration in person B rise after

drinking the glucose drink?

_________________________ mg per 100 cm

3

of blood

(1)

(ii) A doctor suggests that person A has diabetes.

Give two pieces of evidence from the graph to support this suggestion.

1. ____________________________________________________________

______________________________________________________________

2. ____________________________________________________________

______________________________________________________________

(2)

(iii) Give one reason for the fall in blood glucose concentration in person B,

shown in the graph.

______________________________________________________________

(1)

(Total 6 marks)

Q15.

Amylase is an enzyme that digests starch.

A student investigated the effect of pH on the activity of amylase.

This is the method used.

1. Mix amylase solution and starch suspension in a boiling tube.

2. Put the boiling tube into a water bath at 25 °C.

3. Remove a drop of the mixture every 30 seconds and test it for the presence of

starch.

4. Repeat the investigation at different pH values.

The table below shows the students‟ results.

pH

Time when no starch

was

detected in minutes

5.0

7.0

5.5

4.5

6.0

3.0

6.5

2.0

7.0

1.5

7.5

1.5

8.0

2.0

(a) The student concluded pH 7.25 was the optimum pH for the amylase enzyme.

This is not a valid conclusion.

Suggest two reasons why.

1. _________________________________________________________________

___________________________________________________________________

2. _________________________________________________________________

___________________________________________________________________

(2)

(b) The student did another investigation.

This is the method used.

1. Put amylase solution and starch suspension into a boiling tube.

2. Make the pH 7.25.

3. Put the boiling tube into a water bath at 25 °C.

4. Measure the amount of sugar produced every 30 seconds.

The results are shown in the figure below.

Calculate the mean rate of sugar produced per minute during the first 5 minutes.

___________________________________________________________________

Mean rate = ________________ units per minute

(2)

(c) Iodine solution is added to a sample taken from the boiling tube after 10 minutes

and 60 minutes.

Suggest what you would see in these samples.

After 10 minutes _____________________________________________________

___________________________________________________________________

After 60 minutes _____________________________________________________

___________________________________________________________________

(2)

(d) The scientist repeated the investigation at 37 °C.

Draw a line on the figure above to show the results the scientist would get.

(2)

(e) The same investigation was done at 65 °C.

How would this affect the results?

Explain why.

___________________________________________________________________

(3)

(Total 11 marks)

Q16.

Diabetes is a disease in which a person‟s blood glucose concentration may rise.

Doctors give people drugs to treat diabetes.

The table shows some of the side effects on the body of four drugs, A, B, C and insulin,

used to treat diabetes.

Drug

Side effects on the body

A

Weight loss

Liver, kidney and heart damage

Feeling of sickness

B

Weight gain

Damage to some cells in pancreas

C

More water is kept in the body

Weight gain

Increased chance of bone breakage in women

Insulin

A little more water is kept in the body

Weight gain

Increased risk of lung damage

(a) Which drug, A, B, C or insulin, is most likely to result in an increase in blood sugar

concentration in some people?

Explain your answer.

Drug ______________________________________________________________

Explanation

___________________________________________________________________

(2)

(b) (i) Drugs A, B and C can be taken as tablets.

The chemicals in the tablets are absorbed into the blood from the digestive

system.

Insulin is a protein.

Insulin cannot be taken as a tablet.

Why?

______________________________________________________________

(1)

(ii) Other than using drugs, give two methods of treating diabetes.

1. ____________________________________________________________

2. ____________________________________________________________

(2)

(Total 5 marks)

Q17.

The diagram shows the structures involved in a reflex action.

(a) On the diagram, name the structures labelled W, X and Y.

(3)

(b) The control of blood sugar level is an example of an action controlled by hormones.

Give two ways in which a reflex action is different from an action controlled by

hormones.

1. _________________________________________________________________

___________________________________________________________________

2. _________________________________________________________________

___________________________________________________________________

(2)

(Total 5 marks)

Q18.

(a) List A gives the names of three stages in trialling a new drug.

List B gives information about the three stages.

Draw a line from each stage in List A to the correct information in List B.

List A

Stage

List B

Information

Used to find if the drug is toxic

Tests on humans

including a placebo

The first stage in the clinical trials

of the drug

Tests on humans using

very small quantities of

the drug

Used to find the optimum dose

of the drug

Tests on animals

Used to prove that the drug is

effective on humans

(3)

(b) Read the passage.

Daily coffee dose delays development of Alzheimer’s in humans.

Alzheimer‟s is a brain disease that causes memory loss in elderly people.

Scientists studied 56 mice that had been genetically engineered to

develop Alzheimer‟s.

Before treatment all the mice did badly in memory tests.

Half the mice were given a daily dose of caffeine in their drinking water.

The dose was equivalent to the amount of caffeine in six cups of coffee for

a human.

The other mice were given ordinary water.

After two months, the caffeine-drinking mice did better in memory tests

than the mice drinking ordinary water.

The headline for the passage is not justified.

Explain why as fully as possible.

___________________________________________________________________

(3)

(Total 6 marks)

Q19.

(a) Control systems help to keep conditions in the human body relatively constant.

What is the general name for the processes that keep body conditions relatively

constant?

Draw a ring around the correct answer.

eutrophication

homeostasis

hydrotropism

(1)

(b) The concentration of glucose in the blood is controlled by hormones.

Use the correct answer from the box to complete each sentence.

glucagon

glycerol

glycogen

kidney

liver

pancreas

When the blood glucose concentration increases, an organ called

the ______________________ releases the hormone insulin.

Insulin causes glucose to move from the blood into the cells of the muscles

and the ______________________ .

Inside these organs, the glucose is changed into a carbohydrate called

______________________ , which can be stored.

When the blood glucose concentration falls, another hormone is released,

which causes the storage carbohydrate to break down into glucose again.

This hormone is called ______________________ .

(4)

(c) A person with Type 1 diabetes does not make enough insulin.

The person needs to test their blood at intervals throughout the day.

If the concentration of glucose in their blood is too high, the diabetic person needs to

inject insulin.

(i) Insulin is a protein.

It must be injected and cannot be taken by mouth.

Explain why.

______________________________________________________________

(2)

(ii) Apart from injecting insulin, give one other way that a diabetic person

could help to control the concentration of glucose in their blood.

______________________________________________________________

(1)

(d) Pet dogs have been trained to detect if the concentration of glucose in the blood of

their diabetic owners is outside the normal healthy range. These dogs are called

„medical response dogs‟.

The dogs respond in different ways. They may bark, jump up, or stare at their

owners.They may even fetch a blood-testing kit.

(i) Suggest what stimulus the dogs might be responding to when they

behave like this.

______________________________________________________________

(1)

(ii) Table 1 shows how the concentration of glucose varied in blood samples

from five diabetic people. Measurements were made both before and

after getting a medical response dog.

Table 1

Mean percentage of blood samples with

different concentrations of glucose from

the five diabetic people

Number of

blood

samples

measured

Low

glucose

Within

normal

range of

glucose

High

glucose

Before getting a dog

1704

32.6

54.8

12.6

After getting a dog

1724

18.6

61.6

19.8

A survey was made of the effect of a medical response dog on the lives of 16

diabetic people.

Table 2 shows how well these diabetic people agreed with each statement in

the survey.

Table 2

Statement in

Totally

Somewhat

Neither

Somewhat

Totally

survey

agree

nor

disagree

I am more

independent since

getting my dog.

12

2

0

There are

disadvantages to

having a medical

response dog.

0

4

8

I trust my dog to

alert me when my

sugar levels are low.

11

3

1

0

1

I trust my dog to

alert me when my

sugar levels are

high.

6

7

0

1

2

Evaluate how useful medical response dogs are for warning diabetic people

that the concentration of glucose in their blood is outside the normal range.

Use information from Tables 1 and 2.

______________________________________________________________

(5)

(e) Table 3 shows the concentrations of some substances in the urine of a non-diabetic

person and in the urine of a diabetic person.

Table 3

Concentration of substance in urine in g per

dm

3

Substance

Non-diabetic person

Diabetic person

Protein

0

Glucose

0

2.0

Urea

20.0

19.5

Sodium ions

6.0

5.8

Compare the results for the non-diabetic person and the diabetic person.

Give reasons for any differences.

Use your knowledge of how the kidney works.

___________________________________________________________________

(5)

(Total 19 marks)

Q20.

Two people did the same amount of gentle exercise on an exercise cycle.

One person had a muscle disease and the other had healthy muscles.

The graph shows the effect of the exercise on the heart rates of these two people.

(a) Describe three ways in which the results for the person with the muscle disease are

different from the results for the healthy person.

To gain full marks in this question you need to include data from the graph in your

answer.

1. _________________________________________________________________

___________________________________________________________________

2. _________________________________________________________________

___________________________________________________________________

3. _________________________________________________________________

___________________________________________________________________

(3)

(b) The blood transports glucose to the muscles at a faster rate during exercise than

when a person is at rest.

(i) Name one other substance that the blood transports to the muscles at a faster

rate during exercise.

______________________________________________________________

(1)

(ii) People with the muscle disease are not able to store glycogen in their

muscles.

The results shown in the graph for the person with the muscle disease are

different from the results for the healthy person.

Suggest an explanation for the difference in the results.

______________________________________________________________

(3)

(Total 7 marks)

Q21.

This question is about the nervous system.

(a) Describe the function of receptors in the skin.

___________________________________________________________________

(2)

(b) A response is caused when information in the nervous system reaches an effector.

(i) There are two different types of effector.

Complete the table to show:

• the two different types of effector

• the response each type of effector makes.

(4)

(ii) Some effectors help to control body temperature.

Give one reason why it is important to control body temperature.

______________________________________________________________

(1)

(Total 7 marks)

Q22.

The diagram shows the position of two glands, A and B, in a woman.

(a) (i) Name glands A and B.

A ___________________________________

B ___________________________________

(2)

(ii) Gland A produces the hormone Follicle Stimulating Hormone (FSH).

FSH controls changes in gland B.

How does FSH move from gland A to gland B?

______________________________________________________________

(1)

(b) (i) A woman is not able to become pregnant. The woman does not produce

mature eggs. The woman decides to have In Vitro Fertilisation (IVF) treatment.

Which two hormones will help the woman produce and release mature eggs?

Tick ( ) one box.

FSH and Luteinising Hormone (LH)

FSH and oestrogen

Luteinising Hormone (LH) and oestrogen

(1)

(ii) Giving these hormones to the woman helps her to produce several mature

eggs.

Doctors collect the mature eggs from the woman in an operation.

Describe how the mature eggs are used in IVF treatment so that the woman

may become pregnant.

______________________________________________________________

(3)

(iii) IVF clinics have been set a target to reduce multiple births.

At least 76% of IVF treatments should result in single babies

and a maximum of 24% of treatments should result in multiple

births.

Suggest one reason why the clinics have been set this target to reduce

multiple births.

______________________________________________________________

(1)

(c) Two clinics, R and S, used IVF treatment on women in 2007. Doctors at each clinic

used the results of the treatments to predict the success rate of treatments in 2008.

The table shows the information.

Total number of IVF

treatments in 2007

Number of IVF

treatments resulting

in pregnancy in 2007

Predicted

percentage success

rate in 2008

Clinic R

1004

200

18–23

Clinic S

98

20

3–56

(i) Compare the success rates of the two clinics in 2007.

______________________________________________________________

(1)

(ii) The range of the predicted success rate in 2008 for clinic R is much smaller

than the range of the predicted success rate for clinic S.

Suggest why.

______________________________________________________________

(2)

(Total 11 marks)

Q23.

One factor that may affect body mass is metabolic rate.

(a) (i) What is meant by metabolic rate ?

______________________________________________________________

(1)

(ii) Metabolic rate is affected by the amount of activity a person does.

Give two other factors that may affect a person‟s metabolic rate.

1. ____________________________________________________________

______________________________________________________________

2. ____________________________________________________________

______________________________________________________________

(2)

(b) Predicted early death is the number of years that a person will die before the mean

age of death for the whole population. The predicted early death of a person is

affected by their body mass.

Scientists have calculated the effect of body mass on predicted early death.

The graph shows the results of the scientists‟ calculations.

Ideal body mass

The number of times above or below ideal body mass is given by the equation:

In the UK the mean age of death for women is 82.

A woman has a body mass of 70 kg. The woman‟s ideal body mass is 56 kg.

(i) Use the information from the graph to predict the age of this woman when she

dies.

______________________________________________________________

Age at death = ___________ years

(2)

(ii) The woman could live longer by changing her lifestyle.

Give two changes she should make.

1. ____________________________________________________________

______________________________________________________________

2. ____________________________________________________________

______________________________________________________________

(2)

(Total 7 marks)

Q24.

Penguins live mainly in the Antarctic. Penguins eat mainly fish.

Photograph 1 shows a penguin swimming underwater.

Photograph 1

(a) Use information from Photograph 1 to suggest three ways the penguin is adapted

for catching fish.

1. _________________________________________________________________

___________________________________________________________________

2. _________________________________________________________________

___________________________________________________________________

3. _________________________________________________________________

___________________________________________________________________

(3)

(b) The Antarctic winter is very cold. In the winter some species of penguin huddle

together as shown in Photograph 2.

Photograph 2

Suggest how the behaviour shown in Photograph 2 helps the penguins to survive

the Antarctic winter.

___________________________________________________________________

(3)

(c) A student did an investigation to model the behaviour of the penguins shown in

Photograph 2.

The diagram shows the apparatus the student used.

The student:

• held seven similar test tubes together with elastic bands as shown in the

diagram

• stood a similar eighth tube in a test tube rack

• filled each of the eight tubes with hot water to the same level

• measured the temperature of the water in tubes A, B and C every 2 minutes

for 20 minutes.

The table shows the student‟s results.

Time in

Minutes

Temperature in °C

Tube A

Tube B

Tube C

0

65

2

65

64

4

65

64

63

6

64

62

8

64

63

61

10

64

63

60

12

63

62

59

14

63

62

58

16

63

61

57

18

62

61

56

20

62

60

55

(i) Give two variables that were controlled in the investigation.

1. ____________________________________________________________

2. ____________________________________________________________

(2)

(ii) Describe the patterns the data shows.

______________________________________________________________

(2)

(iii) How far does the data from the model support the suggestion you made in part

(b)?

______________________________________________________________

(2)

(d) Describe how blood vessels help control human body temperature.

___________________________________________________________________

(4)

(e) Penguins control their body temperature in similar ways to humans.

Scientists investigated changes in body temperature of penguins when the penguins

were diving to catch fish.

(i) Graph 1 shows the relationship between the temperature of the muscles

moving a penguin‟s wings and diving.

The shaded areas show when the penguin was diving.

Graph 1

Time

Volume 135, P.J. Ponganis,R.P. Van Dam,D.H. Levenson,T. Knower,K.V. Ponganis,G. Marshall, Regional

heterothermy and conservation of core temperature in emperor penguins diving under sea ice, pp 477-487,

Suggest an explanation for the changes in temperature inside the muscles

moving the penguin‟s wings.

______________________________________________________________

(3)

(ii) Graph 2 shows the relationship between the temperature inside a penguin‟s

foot and diving.

The shaded areas show when the penguin was diving.

Graph 2

Time

Volume 135, P.J. Ponganis,R.P. Van Dam,D.H. Levenson,T. Knower,K.V. Ponganis,G. Marshall, Regional

heterothermy and conservation of core temperature in emperor penguins diving under sea ice, pp 477-487,

Suggest an explanation for the changes in temperature inside the penguin‟s

foot as it dives.

______________________________________________________________

(3)

(Total 22 marks)

Q25.

The rate of chemical reactions can be changed by changing the conditions.

(a) Methane burns in oxygen to produce carbon dioxide and water.

The activation energy for the reaction is 2648 kJ / mol.

The reaction gives out 818 kJ / mol of energy.

The figure below shows the reaction profile for this reaction.

Complete the reaction profile.

Draw arrows to represent:

• the activation energy

• the energy given out.

(4)

(b) What percentage of the activation energy is the energy given out?

___________________________________________________________________

(1)

(c) Calcium carbonate decomposes when it is heated:

The decomposition of calcium carbonate is an endothermic reaction.

How would the reaction profile for decomposition of calcium carbonate be different

from the reaction profile of methane burning in oxygen?

___________________________________________________________________

(1)

(d) Catalysts are used in chemical reactions in industry.

Give two properties of catalysts.

For each property, explain why it makes the catalyst useful in industry.

___________________________________________________________________

(4)

(e) Enzymes are biological catalysts.

What type of molecule is an enzyme?

Tick one box.

Carbohydrate

Hydrocarbon

Lipid

Protein

(1)

(f) If enzymes are denatured they stop working.

Give two ways an enzyme can be denatured.

1. _________________________________________________________________

2. _________________________________________________________________

(2)

(g) An enzyme called lactase catalyses the reaction that breaks down lactose to smaller

molecules.

One model used to explain how enzymes affect reactions is called the lock and key

model.

Use the lock and key model to explain why lactase cannot be used to speed up all

chemical reactions.

___________________________________________________________________

(3)

(Total 16 marks)

Q26.

The nervous system allows humans to respond to their surroundings.

The figure below shows two nerve pathways.

Nerve pathway A Nerve pathway B

(a) Nerve pathway A is 92 cm long.

A nerve impulse travels along pathway A at 76.2 m / s.

Calculate how long it takes for the nerve impulse to travel the length of the pathway.

Use the equation:

distance = speed × time

___________________________________________________________________

Time = _________________ s

(3)

(b) Nerve pathways A and B are the same length.

The nerve impulse takes longer to travel along pathway A than along pathway B.

Use the figure above to explain why.

___________________________________________________________________

(3)

(c) Two students compare their reactions using a ruler.

This is the method used.

1. Student A sits with his elbow on a table top.

2. Student B holds the ruler so the bottom of the ruler is level with the top of

student A‟s thumb.

3. Student B drops the ruler.

4. Student A catches the ruler.

5. Record the drop distance.

6. Repeat steps 1 to 5 four more times.

7. Repeat the whole experiment with student A dropping the ruler and student B

catching it.

Both students are right-handed.

Student A uses his right hand to catch the ruler.

Student B uses her left hand to catch the ruler.

The table below shows the students‟ results.

Student

Drop distance in mm

Test 1

Test 2

Test 3

Test 4

Test 5

Student A – right

hand

203

167

140

156

163

Student B – left

hand

230

211

279

215

264

What is the range of student A‟s results?

___________________________________________________________________

(1)

(d) The students are testing the hypothesis:

The drop distance of the ruler is smaller when a right-handed person uses

their right hand to catch the ruler.

The students‟ results in the table above are not a good test of the hypothesis.

Suggest what the students should have done to test the hypothesis.

___________________________________________________________________

(3)

(e) Student A‟s mean reaction time was 0.19 s.

Mean reaction time can be calculated using the equation:

Calculate the mean reaction time for Student B.

Give your answer to two significant figures.

Student B‟s results are repeated here to help you answer the question.

Drop distance in mm

Test 1

Test 2

Test 3

Test 4

Test 5

Student B – left

hand

230

211

279

215

264

___________________________________________________________________

Mean reaction time = ____________ s

(4)

(Total 14 marks)

Q27.

This question is about hormones.

(a) (i) Hormones carry messages.

What type of messenger is a hormone?

Draw a ring around the correct answer.

chemical

electrical

environmental

(1)

(ii) Which part of the brain secretes hormones?

Draw a ring around the correct answer.

cerebellum

medulla

pituitary gland

(1)

(b) Figure 1 shows the level of a pregnancy hormone over a 40-week pregnancy.

This hormone can be detected in a pregnancy test.

Figure 1

A woman takes a pregnancy test.

In which week of pregnancy is the test most likely to give a positive result?

Use information from Figure 1.

Write the correct answer in the box.

(1)

(c) Figure 2 shows the levels of three other hormones during pregnancy.

The baby is usually born at about 40 weeks.

Figure 2

Adaptation by kind permission of Biozone International

(i) Describe the patterns in the levels of oestrogen and progesterone from 0

to 36 weeks.

______________________________________________________________

(4)

(ii) Which hormone is likely to stimulate contractions of the uterus (womb)

when the baby is born?

Use information from Figure 2 to give a reason for your answer.

______________________________________________________________

(2)

(Total 9 marks)

Q28.

The human body is organised to carry out many different functions.

(a) Use words from the box to complete Figure 1 by putting the parts of the body in

order of size from smallest to largest.

The smallest one has been done for you.

(2)

(b) The stomach is made of different types of tissue.

Draw one line from each type of stomach tissue to the correct description.

(3)

(c) Animals can react to their surroundings because they have nervous systems.

A student investigated the behaviour of small animals called woodlice.

The student set up the investigation as shown in Figure 2.

• The student covered one half of a Petri dish with black paper to make that side

of the Petri dish dark.

• The other side had no cover.

• The student put five woodlice into each side of the dish and then put the clear

Petri dish lid back on the dish.

Figure 2

After 30 minutes, all the woodlice had moved to the dark side of the Petri dish.

(i) In this investigation, what is the stimulus that the woodlice responded

to?

______________________________________________________________

(1)

(ii) In this investigation, what is the response that the woodlice made?

______________________________________________________________

(1)

(iii) The student concluded that woodlice prefer dark conditions.

Give two ways in which the student could improve the investigation to be sure

that his conclusion was correct.

1. ____________________________________________________________

______________________________________________________________

2. ____________________________________________________________

______________________________________________________________

(2)

(Total 9 marks)

Q29.

Amylase catalyses the breakdown of starch into sugars.

A student investigated the effect of amylase on the reaction at different temperatures.

Figure 1 shows the apparatus the student used.

Figure 1

This is the method used.

1. Put starch suspension into a test tube.

2. Add amylase solution.

3. Put the test tube in a beaker of water at 15 °C.

4. Remove a small sample of the mixture every 30 seconds and put in a spotting tile.

5. Test the sample for starch.

6. Time how long it takes to break down all of the starch in the mixture.

7. Repeat steps 1–5 at 20 °C, 25 °C and 30 °C.

8. Repeat for each temperature twice more.

The table below shows the student‟s results.

Time taken until there was no starch in the

sample in minutes

Temperature

in °C

Test 1

Test 2

Test 3

Mean

15

6.1

9.4

10.0

8.5

20

4.8

5.0

4.6

4.8

25

3.0

2.5

3.0

3.2

30

1.5

2.0

(a) One of the results in the table above is anomalous.

Draw a ring around the anomalous result.

(1)

(b) Calculate the mean for 30 °C.

___________________________________________________________________

(1)

(c) Figure 2 shows a graph of the student‟s results.

Figure 2

Use the graph to predict how long it would take to break down all of the starch at

10 °C.

Time = _________________ minutes

(1)

(d) The student tested samples of the mixture for starch every 30 seconds.

In each test she added one drop of iodine to the sample in the spotting tile.

Predict the colour of the samples from the 20 °C test at 4.0 minutes and

7.0 minutes.

Colour at 4.0 minutes __________________________________________

Colour at 7.0 minutes __________________________________________

(2)

(e) The student did a fourth test at 30 °C.

In this test the starch did not break down, even after 45 minutes.

Why did the amylase not break down the starch in this test?

Tick one box.

The amylase solution and the starch suspension were

mixed before the start of the experiment.

The amylase solution had been prepared with water at

95 °C.

The amylase solution had been prepared with water at

20 °C.

The amylase solution had been stored in the fridge.

(1)

(f) The student made the following conclusion about the optimum temperature for

amylase to work at.

„Amylase works fastest at 40 °C‟

Her teacher said that this is not a valid conclusion from her results.

Describe how the student could change her method to give results that would

improve the validity of her conclusion.

___________________________________________________________________

(6)

(Total 12 marks)

Q30.

Neurones pass information around the body.

(a) Why are reflex reactions important?

___________________________________________________________________

(1)

(b) Caffeine is a drug found in coffee.

After a person drinks coffee information passes through neurones in the nervous

system more quickly.

Suggest a hypothesis for the effect of caffeine concentration on reaction time.

___________________________________________________________________

(1)

(c) Two students investigated the effect of caffeine concentration on reaction time.

This is the method used.

1. Student A drinks a cup of coffee.

2. Student B holds a ruler above Student A‟s hand.

3. Student B drops the ruler.

4. Student A catches the ruler as quickly as she can.

5. The distance the ruler falls is recorded.

Suggest how this method could be improved to produce valid results.

___________________________________________________________________

(6)

(Total 8 marks)

Q31.

Glycogen is stored in the muscles.

Scientists investigated changes in the amount of glycogen stored in the muscles of two

20-year-old male athletes, A and B.

Athlete A ate a high-carbohydrate diet. Athlete B ate a low-carbohydrate diet.

Each athlete did one 2-hour training session each day.

The graph shows the results for the first 3 days.

(a) (i) Give three variables that the scientists controlled in this investigation.

______________________________________________________________

(3)

(ii) Suggest two variables that would be difficult to control in this investigation.

______________________________________________________________

(2)

(iii) Describe one way in which the results of Athlete B were different from the

results of Athlete A.

______________________________________________________________

(1)

(b) Both athletes were training to run a marathon.

Which athlete, A or B, would be more likely to complete the marathon?

Use information from the graph to explain your answer.

___________________________________________________________________

(4)

(Total 10 marks)

Mark schemes

Q1.

(a) B

no mark for ÉBÉ, alone

large(r) surface / area or large(r) membrane

accept reference to microvilli

accept reasonable descriptions of the surface

do not accept wall / cell wall

ignore villi / hairs / cilia

1

(b) (i) any one from:

• insulin / hormone

if named hormone / enzyme must be correct for pancreas

• enzyme / named enzyme

1

(ii) many ribosomes

1

(ribosomes) produce protein

accept insulin / hormone / enzyme named is (made of)

protein

or

allow many mitochondria (1)

provide energy to build protein or to make protein (1)

accept ATP for energy

1

[4]

Q2.

(a) (i) pancreas

allow phonetic spelling

1

(ii) glucose into cells / liver / muscles

allow any named organ / cell

allow turned into / stored as glycogen

but

do not allow hybrid spellings for glycogen

allow increases respiration

allow stored as / turned into fat

1

(b) (i) reference to “98.6% of all people who used Diacure reported

an improvement in their condition”.

allow claim 1 / 1 / the first one

1

(ii) (only) 30 patients or not enough / not many patients

allow only one trial or only done once or not repeated

ignore bias

1

(iii) little effect / difference

allow no effect

allow only drops by 4 (±1)

1

suggest drug is not effective (in long term)

allow wouldn’t persuade people to take it

1

(iv) avoid bias / owtte

eg company could change / ignore results / might lie

ignore fair / accurate / reliable / valid

1

[7]

Q3.

(a) (i) endocrine glands or endocrine system

allow a specific named gland

1

(ii) (dissolved) in the blood(stream) or plasma

1

(b) (i) pancreas or islets of Langerhans

1

(ii) (it or insulin) lowers blood sugar level [1]

(by) (speeding up or increasing)

conversion of glucose to glycogen [1]

in the liver [1]

(and) speeding up or increasing uptake of glucose by body cells [1]

4

[7]

Q4.

(i) liver

1

(ii) liver or B stores glycogen

or pancreas or D makes insulin

1

clear description of link

1

[3]

Q5.

(a) label drawn to the hand

may be labelled as ‘a’

accept the receptor identified as the hand

1

(b) label drawn to the muscle

may be labelled as ‘b’

accept the effector identified as the muscle

1

(c) (i) sharp point or heat

accept specific examples such as pain, bee sting, cut,

burning

do not accept touch by itself

1

(ii) move the hand (or arm) away from stimulus

or

muscle in the arm contracts

do not credit reference to impulse reaching brain unless it is

clear that this is in addition to the reflex act

do not credit ‘reflex action ‘ already given

1

(d) an arrow on the sensory fibre from

hand to spine

award one mark for both arrows in the correct direction

and

• note the arrows may be drawn separately from the

printed

neurone

an arrow on the motor fibre from

spine to muscle

• do not credit if the impulse travels to the muscle via

the brain but a ‘one way’ journey to the brain will be

neutral

1

[5]

Q6.

(a) oxygen; )

carbon dioxide; ) allow symbols

water )

each for 1 mark

3

(b) graph with reasonable vertical scales;

accurate plotting of all points (ignore lines) and labelling lines

histogram – must be coded

gains 3 marks

3

(c) 6 of:

during exercise the level of CO

2

(in the blood) rises;

increased breathing to remove excess CO

2

;

increased oxygen supply to muscles;

or increased breathing takes in more O

2

or increased heart rate takes more O

2

to muscles;

increased supply of sugar to muscles;

increased respiration rate;

enable faster rate of energy release;

reference to lactic acid (allow even though not on syllabus)/O

2

debt;

to avoid cramp;

anaerobic reference;

reference to removal of „heat‟;

6

(d) high carbon dioxide concentration;

brain/central nervous system;

heart muscles (both)

3

[15]

Q7.

(a) 345 to 350

ignore working or lack of working

use of 355 to 360 and 10 for 1 mark

2

(b) any two from:

more sweating (at 37.6 °C)

‘more’ at least once in the first 2 points

more water loss or dehydration occurs

do not accept prevents dehydration only

blood becomes (more) concentrated / (more) salty or need to replace water

stimulation of the hypothalamus

2

(c) any three from:

evaporation

of water

do not accept just water loss unqualified

cools skin or uses heat from skin

cools blood / heat from blood (passing through skin)

related to sweating

cooling the blood

ignore vasodilation

3

[7]

Q8.

(a) (i) any one from:

• chemical messenger

• chemical / substance released in one part

to have effect elsewhere in body

• chemical / substance which affects

another / target organ / tissues / cells

allow chemical from endocrine gland

1

(ii) in blood / circulatory system / any named part including plasma

extra wrong answer would cancel example

not red blood cells

1

(b) Quality of written communication:

correct use of at least two relevant scientific terms spelt phonetically

e.g. pregnancy, ovulation, FSH, oestrogen, progesterone,

ovary, follicle, circulation, thrombosis, feminisation, sperm

count, STD

Q or Q

1

any three from:

Oral contraceptives:

(benefit)

• prevent (unwanted) pregnancy or prevent egg release

• regulate menstrual cycle / periods

(problems)

• prolonged use may prevent later ovulation / cause infertility

• named side-effect on female body

e.g. circulatory problems / weight gain / nausea / headache /

breast cancer / mood swings

• increased promiscuity / increase in STD‟s / STI‟s

• named side-effect on environment

e.g. feminisation of fish or lowered sperm count in human males

Fertility drugs:

(benefit)

• can enable woman to have children or to become pregnant

or stimulates egg release

(problem)

• multiple births

for full marks must score at least one re contraceptives and

at least one re fertility drugs

if unclear which type of hormone maximum 2 marks from 3

3

[6]

Q9.

(a) any two from:

• amylase / carbohydrase

• protease

allow trypsin

• lipase

2

(b) (i) high / above normal blood sugar

or cannot control blood sugar

allow other symptoms

eg frequent / plentiful urination or sugar in urine or thirst or

weight loss or coma

ignore consequential effects eg blood pressure / circulation /

glaucoma / tiredness

1

(ii) any one from:

• small / regular meals

• low sugar (meals) or low GI / GL or carbohydrates as starch

allow high fibre

ignore reference to low carbohydrate

1

(iii) any one from:

• keep constant( blood) sugar or prevent high (blood) sugar

or reduces surge / rush of sugar into blood

• reduce the need for insulin

1

(iv) (take) insulin

allow pancreas transplant

1

(c) protein / hormone / enzyme synthesis or synthesis of named example

or combine amino acids

1

[7]

Q10.

(a) (i) 6

1

(ii) 4

1

(b) (i) pancreas

ignore islets of langerhans

1

(ii) „X‟ anywhere between >1 and ≤ 2 hours

anywhere in that column

1

(c) any four from:

water movement

do not accept solution

out of cells

dilute to concentrated solution

accept reference to correct gradient -

high to low or high to low ‘water concentration’

must be unambiguous – i.e. not ‘high to low concentration’

accept low to high concentration

reference to partially / selectively

permeable membranes or described

cells shrink / get smaller

allow crenated

ignore plasmolysed / flaccid / floppy

etc

4

[8]

Q11.

(a) (i) receptor

allow named receptor eg light receptor

ignore sensory neurone

allow sense organ / named sensory organ eg skin / eye

1

(ii) sensory (neurone)

allow afferent

1

(iii) motor (neurone)

allow efferent

1

(iv) effector / muscle / gland / named

1

(b) any two from:

• impulse / information passes from one neurone to another

or impulse / information passes across gap

• chemical / transmitter involved

• diffusion (across gap)

2

(c) brain / person not aware of pain / stimulus / can‟t feel

allow brain/ person doesn’t know / realise / unable to

coordinate

ignore reflex

ignore information

1

possibility of (permanent / serious) damage / eg burning

ignore danger

1

[8]

Q12.

(a) pancreas

allow phonetic spelling

1

(b) 4(.0) to 7.2 or 7.2 to 4(.0)

1

(c) 13 – 7 = 6

working shows 6 = 1 mark

1

6/2 = 3 units

accept the correct answer to the calculation, 3 units, for 2

marks, irrespective of working

1

increase (dose)

accept indication of increase, eg extra / more / + could be in

working lines

1

[5]

Q13.

(a) (i) any one from:

• chemical messenger / message

allow substance / material which is a messenger

• chemical / substance produced by a gland

allow material produced by a gland

• chemical / substance transported to / acting on a target organ

• chemical / substance that controls body functions

1

(ii) gland / named endocrine gland

brain alone is insufficient

allow phonetic spelling

1

(iii) in blood / plasma or circulatory system or bloodstream

accept blood vessels / named

do not accept blood cells / named

1

(b) each hormone must be linked to correct action

apply list principle

ignore the gland producing hormone

FSH stimulates oestrogen (production) / egg maturation / egg ripening

ignore production / development of egg

1

oestrogen inhibits FSH

allow oestrogen stimulates LH / build up of uterine lining

1

LH stimulates egg / ovum release / ovulation

accept LH inhibits oestrogen

accept LH controls / stimulates

growth of corpus luteum

ignore production of egg

1

[6]

Q14.

(a) (i) insulin

accept glucagon (correct spelling only)

1

(ii) pancreas

accept phonetic spelling

allow pancrease

1

(b) (i) 11(.0)

accept in range 10.5-11 (.0)

1

(ii) any two from:

ignore numbers unless comparative

• high(er) concentration (of blood glucose) (anywhere / any time)

accept 115 not 88

139 not 99

• large(r) increase (in concentration after the drink)

accept increase by 24 not 11 / their b(i)

• fast(er) / steep(er) rise

accept it takes 3 hours not 1 ¼ hours to get back to original

level

accept it takes a long time to get back to normal

• slow(er) fall

2

(iii) any one from:

• insulin present / produced

accept glucagon not produced

• (used in) respiration

allow exercise

• taken into cells

allow converted to glycogen

allow taken into liver (cells) / muscle (cells)

allow produce / make energy

1

[6]

Q15.

(a) any two from:

• same result at pH 7 and 7.5

or

could be any pH between 7 and 7.5

or

not tested at pH 7.25

or

need to test at smaller pH intervals (between 7 and 7.5)

• accuracy of result only to nearest 0.5 minutes

• no repeats

• difficult to determine end point (colour)

2

(b) 2.7 / 5

1

0.54 (units per minute)

allow 0.52 with no working shown for 2 marks

1

allow 1 mark for 0.52 or 0.56

(c) (after 10 minutes) solution goes black

1

(after 60 minutes) solution stays the same

or

does not go black

or

goes slightly orange

1

(d) steeper curve

1

levels off at 11.8 units and before 45 minutes

1

(e) no / little sugar produced

allow a correct description of what the graph would look like

1

(because at 65 °C) the enzyme will be denatured

allow (because) the enzyme’s shape will be changed

or

(because) the active site is damaged

1

(so) will no longer fit the starch

or

(so) will not be able to catalyse the reaction

1

[11]

Q16.

(a) B

1

less / no insulin (produced) or insulin produced in pancreas

allow pancreas can’t monitor (blood) sugar (level)

ignore pancreas can’t control (blood) sugar (level)

allow increased glucagon production

allow A as liver stores less glucose / sugar for 2 marks only

1

(b) (i) (it / protein / insulin) digested / broken down

if ref to specific enzyme must be correct (protease / pepsin)

ignore denatured

do not accept digested in mouth / other incorrect organs

1

(ii) any two from:

ignore injections

• (attention to) diet

accept examples, eg eat less sugar(y food) or eat small

regular meals

allow eat less carbohydrate / control diet

ignore cholesterol or balanced / healthy diet

• exercise

ignore keep fit / healthy

• (pancreas) transplant / stem cells / genetic engineering

2

[5]

Q17.

(a) Y - spinal cord / central nervous system / CNS

do not accept spine

ignore nerve / nervous system / coordinator

ignore grey / white matter

1

W - receptor / nerve ending

ignore sensory / neurone / stimulus

1

X - effector / muscle

allow gland

1

(b) any two from: eg

accept reverse argument for each marking point

• reflex action quicker

• effect of reflex action over shorter period

• hormone involves blood system and reflex involves neurones / nerve cells

ignore nervous system / nerves

• reflex involves impulses and hormone involves chemicals

• reflex action affects only one part of the body

ignore involves brain

ignore outside / inside stimuli

2

[5]

Q18.

(a)

1 mark for each correct line

mark each line from left hand box

two lines from left hand box cancels mark for that box

3

(b) any three from:

Students have been informed that the headline is not

justified

• reference to reliability, eg only a small number of mice tested

or trial too short

or investigation not repeated

• reference to control, eg mice given caffeine not coffee

or 6 cups (equivalence) is more than 1 dose

• (and) the effect on mice might not be same as on humans

allow only tested on mice

• (also) text suggests that the treatment improves memory loss (rather than

delays it)

accept text suggests disease cured

or mice already have memory loss or experiment only showed improvement in

memory

or does not show delays Alzheimer‟s

or experiment not done on old mice

allow reference to the fact that mice engineered to have it

3

[6]

Q19.

(a) homeostasis

1

(b) in sequence:

pancreas

1

liver

1

glycogen

correct spelling only

1

glucagon

correct spelling only

1

(c) (i) broken down / digested

1

further detail eg into amino acids / by enzymes / by proteases

1

(ii) diet / eating less sugar / less fat

ignore balanced diet

or

ignore ‘dieting’ / slimming diet

exercise

accept pancreas transplant

1

(d) (i) sensible suggestion

eg (owner‟s) smell / sweating / change in owner‟s behaviour / dizziness /

tiredness

1

(ii) any five from:

allow 1 mark for justified conclusion

do not allow full marks unless at least 1 pro and 1 con.

Pro:

• % below normal decreases

• % in normal increases

• reliable / repeatable / valid data as large number of samples

do not allow accurate / precise

• patients express satisfaction.

Con:

• may not be reliable as blood glucose measurements for only 5

patients / survey of only 16 (dog owners)

• % above normal increases / dogs are less good at detecting high

glucose.

5

(e) glucose in urine of diabetic (and not in the non-diabetic)

1

urea and Na+ ions are similar in each / slightly lower in diabetic

1

+ any three from:

• no protein in either urine sample because protein too large / does not

pass through filter

• glucose passes through filter in kidney

ignore glucose is reabsorbed

• non-diabetic: the / all glucose is reabsorbed / taken back into blood

• diabetic: (too much glucose so) cannot all be reabsorbed

• because diabetic has high concentration of glucose in blood

• urea and Na+ lower in diabetic because less water is reabsorbed (due to

extra glucose in filtrate).

3

[19]

Q20.

(a) person with muscle disease:

allow reverse argument for healthy person

any three from:

NB all points are comparative except peak (point 3)

allow use of two approximate figures as a comparison

• higher resting rate or higher at start

• when exercise starts / then increases more / more rapidly

accept description eg rise …. fall

• peaks (then falls)

• levels off later than healthy person

• higher rate during exercise

if no other marks awarded allow 1 mark for ‘it’s higher’

• greater range

3

(b) (i) oxygen

accept adrenaline

accept O

2

do not accept O, O2 or O

2

1

(ii) cannot release sugar / glucose (from glycogen)

or

cannot store glucose / sugar (as glycogen)

1

need to receive glucose / sugar (from elsewhere)

ignore oxygen

1

for energy / respiration / cannot store energy

ignore aerobic / anaerobic

1

[7]

Q21.

(a) detect changes in surroundings or detect stimuli

allow any named stimulus for skin

1

convert information to impulse

allow send impulse to sensory neurones / brain

1

(b) (i)

muscle

contract(ion)

gland

release / secrete /

produce chemical

/ hormone /

enzyme

1 mark for each effector

1 mark for each response

response must match type of effector (if given)

ignore examples

ignore relax(ation) / movement for contraction

do not allow expansion for muscles

4

(ii) any one from:

• (maintain temperature at which) enzymes work best

• so chemical reactions are fast(est)

• prevent damage to cells / enzymes

allow prevent enzymes being denatured (by temperature

being too high)

1

[7]

Q22.

(a) (i) A – pituitary

allow hypothalamus

1

B – ovary / ovaries

1

(ii) in blood (stream)

accept in plasma

ignore dissolved

1

(b) (i) FSH and Luteinising Hormone (LH)

1

(ii) fertilised

OR

reference to sperm

1

form embryos / ball of cells or cell division

1

(embryo) inserted into mother‟s womb / uterus

allow (fertilised egg) is inserted into mother’s womb / uterus

1

(iii) any one from:

• multiple births lead to low birth weight

• multiple births cause possible harm to mother / fetus / embryo /

baby / miscarriages

allow premature

ignore reference to cost / ethics / population

1

(c) (i) any one from:

• almost identical

allow S (slightly) more successful

• both approximately 20%

1

(ii) larger numbers (in clinic R) (in 2007)

allow only 98 (in S) (compared to 1004 (in R))

1

results likely to be more repeatable (in 2008)

allow more reliable

do not accept more reproducible / accurate / precise

1

[11]

Q23.

(a) (i) rate of chemical reactions (in the body)

1

(ii) any two from:

• heredity / inheritance / genetics

• proportion of muscle to fat or (body) mass

allow (body) weight / BMI

• age / growth rate

• gender

accept hormone balance or environmental temperature

ignore exercise / activity

2

(b) (i) 77

correct answer with or without working gains 2 marks

allow 1 mark for 70 / 56 or 1.25 or 5

2

(ii) increase exercise

accept a way of increasing exercise

1

reduce food intake

accept examples such as eat less fat / sugar

allow go on a diet or take in fewer calories

ignore lose weight

ignore medical treatments such as gastric band / liposuction

1

[7]

Q24.

(a) any three from:

• streamlined shape enables it to swim quickly (to catch fish)

• wings (provide power) to move quickly (to catch fish)

allow ‘flippers’

• wings used for steering

• white underside / dark top acts as camouflage (so prey less likely to see it)

• long / sharp beak to catch fish

3

(b) any three from:

• reduces (total) surface area of penguins exposed to wind / cold atmosphere

• reduced number of penguins exposed (to wind / cold)

accept reference to movement in or out of the huddle

accept outer ones insulate / act as barrier

• reducing heat loss

allow reduced cooling

• „share‟ body warmth / heat

3

(c) (i) any two from:

• size of tubes

• volume of (hot) water

accept amount of (hot) water

• left for same length of time

allow measured at same time intervals

• starting temperature

2

(ii) any two from:

• tube alone (C) lost heat most (rapidly)

• tube B intermediate

• tube A least (rapidly)

allow correct use of figures for all 3 tubes

ignore just quoting final temperature

2

(iii) confirms suggestion

no mark awarded

accept correct answers referring to other suggestions in (b)

since (both outer and inner) tubes in bundle lost heat less rapidly (than

„stand − alone‟ tube)

comparison needed

1

penguins in a huddle lose less heat (than single ones)

accept ‘it is the same for penguins’

1

(d) if the core body temperature is too high

blood vessels supplying the skin (capillaries) dilate / widen

accept reference to arteries / arterioles but not veins /

capillaries

do not accept references to movement of blood vessels

ignore enlarge / expand

reference to skin / surface required only once

1

so that more blood flows through the (capillaries) in skin / near surface

reference to ‘more’ needed at least once to gain 2 marks

1

and more heat is lost

reference to ‘more’ needed at least once to gain 2 marks

1

if the core body temperature is too low

blood vessels supplying the skin (capillaries) constrict / narrow

allow full marks if ‘too low’ given first

if no other marks awarded, allow vasodilation when too warm

and vasoconstriction when too cold for 1 mark

1

(e) (i) wings move to provide movement for diving

allow muscles contract / work

1

energy (for movement) comes from respiration

do not allow produces / makes / creates energy

allow energy comes from / is supplied by / is released by

respiration

1

respiration / muscle contraction also releases heat

allow produces heat

1

(ii) any three from:

• feet not / less used or no muscle contraction in feet

allow little energy / heat released through respiration in feet

do not allow veins / capillaries

• vessels supplying feet constrict / less blood to feet

• so temperature in feet cools / decreases

• more heat loss from large surface area or rapid flow of cold water over

foot

3

[22]

Q25.

(a) products below reactants

1

correct energy profile

1

activation energy correctly labelled

1

energy given out correctly labelled

1

(b) 31 (%)

1

(c) the products would be above the reactants

1

(d) catalysts increase rate of reaction

1 mark for each property

1 mark for each explanation

so products formed in less time

or

catalysts lower activation energy

explanation must be linked correctly to the property to gain

the mark

so lowers energy requirements

or

catalysts not used up in the reaction

so only an initial outlay needed

or

only a small amount of catalyst needed

so small initial cost

max. 4

(e) Protein

1

(f) high temperatures

1

extremes of pH

1

(g) lactase acts as the lock, lactose is the key (substrate)

1

lactase has an active site which will only fit lactose molecules

1

so lactase will not work with other molecules

1

[16]

Q26.

(a) 0.92 = 76.2 × time

1

time = 0.92 ÷ 76.2

1

= 0.012

allow 0.012 with no working shown for 3 marks

1

(b) pathway B has two synapses

allow converse for pathway A

1

chemicals diffuse across each synapse

1

which slows down the impulse

1

(c) 140−203

1

(d) use the same person for each test

1

use left hand and right hand

1

use a bigger sample size or more people

allow take more readings with each person

1

(e) mean drop distance = (230 + 211 + 279 + 215 + 264) ÷ 5 = 239.8

1

239.8 mm = 0.2398 m

1

mean reaction time =

1

= 0.221

incorrect sig. figs max. 3 marks

1

allow 0.221 with no working shown for 4 marks

[14]

Q27.

(a) (i) chemical

1

(ii) pituitary gland

1

(b) 8

allow 9 or 10

1

(c) (i) any four from:

• progesterone starts being produced at 4 weeks / no progesterone

before 4 weeks

• and then / from 4 weeks increases

• oestrogen at constant / low level (from 0) to 20 weeks

• and then / from 20 weeks increases

• from 20 − 36 weeks level of O rises more steeply than that of P

or

• P is always higher than 0 from 6 to 36 weeks

if no other marks awarded, allow progesterone and

oestrogen both increase / rise for 1 mark.

4

(ii) oxytocin

1

level of oxytocin increases just before birth

1

[9]

Q28.

(a) tissue → organ → organ system

one right for 1 mark

three right for 2 marks

2

(b) Epithelial tissue → covers the outside and the inside of the stomach

more than one line from a tissue = no mark

1

Glandular tissue → produces digestive juices

1

Muscular tissue → allows food to be churned around the stomach

1

(c) (i) light

ignore dark

1

(ii) moving (to the dark)

1

(iii) any two from:

• use more woodlice

• repeat the experiment

• run for a longer time

2

[9]

Q29.

(a) 6.1 circled on table (15 °C, test 1)

1

(b) 1.8

do not allow 1.83

1

(c) 16 (minutes)

correct number extrapolated from curve

1

(d) 4.0 min – blue / black / purple

1

7.0 min – yellow / orange / brown

1

(e) The amylase solution had been prepared with water at 95 °C

1

(f) Level 3 (5–6 marks):

A clear and coherent method is described using logical steps and demonstrating a

good understanding of how to improve the validity of the method. The method would

lead to

the production of valid results that would give rise to a more valid conclusion.

Level 2 (3–4 marks):

The substantive content of a method is present and demonstrates reasonable

understanding of how to improve the validity but may be missing some detail. The

plan

may not be in a completely logical sequence but leads towards the measurement of

rate of the reaction.

Level 1 (1–2 marks):

Simple relevant statements made, which demonstrate limited understanding of how

to improve the experimental method. The response lacks logical structure and would

not

lead to the production of valid results or a more precise optimum temperature.

0 marks:

No relevant content

Indicative content

• conduct at a greater range of temperatures

• use temperatures both above and below 40 °C

• use smaller temperature intervals to get a more accurate optimum (eg

go

up in 2 °C increments)

• take samples at smaller time intervals to get a more accurate result for

„time taken‟

• control the volume of starch used (eg 5 cm

3

)

• control the volume of the amylase solution (eg 1 cm

3

)

• control the temperature (eg using a water bath)

• heat the two solutions separately before mixing

• control the concentration of the starch solution

• control the concentration of the amylase solution

6

[13]

Q30.

(a) fast reaction to reduce / protect from harm

allow named examples

1

(b) higher caffeine concentration causes shorter reaction time.

allow converse

ignore ‘faster / slower reaction time’

1

(c) Level 3 (5–6 marks):

A coherent method is described with relevant detail, which demonstrates a broad

understanding of the relevant scientific techniques and procedures. The steps in the

method are logically ordered. The method would lead to the collection of valid

results.

Level 2 (3–4 marks):

The bulk of a method is described with mostly relevant detail, which demonstrates a

reasonable understanding of the relevant techniques and procedures. The method

may

not be in a completely logical sequence and may be missing some detail.

Level 1 (1–2 marks):

Discrete relevant points are made which demonstrate some understanding of the

relevant scientific techniques and procedures. They may lack a logical structure and

would not

lead to the production of valid results.

0 marks:

No relevant content.

Indicative content

• use decaffeinated coffee as control

• control volume of coffee

• blind trial or do not tell students which coffee they are drinking

• left for standard time between drink and test

• at least 10 minutes

• control start position of ruler

• control other factors such as light in the room

• same person for different concentrations

• repeat for each caffeine concentration

• use a range of caffeine concentrations

• start with lowest concentration of caffeine

• use caffeine solution instead of coffee to control for other ingredients

• repeat investigation with more people and calculate means

6

[8]

Q31.

(a) (i) any three from:

if diet given as answer = max 2

• age (of athlete)

• gender (of athlete)

• starting concentration of glycogen

• type / intensity of exercise

• length of exercise period

• number of training sessions

if none of these points gained amount of exercise = 1 mark

• time interval between exercise sessions

• exercise at same time of day

if last four points not awarded allow time (for exercise) for 1

mark

ignore references to amount of energy

ignore they are both athletes

3

(ii) any two from:

• intensity of exercise

• amount of exercise between sessions

• starting concentration of glycogen

• fitness / health

• metabolic rate / respiration rate

• amount / mass of muscle / physique

• aspects of diet qualified, eg amount of food eaten

do not accept amount of carbohydrate

if no other marks awarded allow height / mass / weight for 1

mark

2

(iii) (B has) less glycogen

he = B

or (B‟s glycogen) fell more

accept use of approximate figures

or (B‟s glycogen) built up less

allow other correct observations from graph eg A is lower at

end of first session

ignore rate of fall

1

(b) athlete A (no mark)

to gain full marks ‘more’ must be given at least once

athlete A had more glycogen / B has less (only if A chosen to complete marathon)

accept converse argument for B

1

(glycogen / glucose) used in respiration

ignore anaerobic

1

(more) energy released / available in athlete A

allow ‘energy made’

1

and either energy used for movement / muscle action / to run

or

(extra) glycogen → (more) glucose

1

[10]