Carbon dioxide

Carbon dioxide

A stomach B mouth C duodenum D pancreas. The correct answer is A—stomach. The answer A has been clearly marked in pencil with a horizontal line (see below).





Changing an answer If you decide to change your answer, carefully erase your first answer and, using your pencil, fill in the answer you want. The answer below has been changed to D.






SECTION A All questions in this section should be attempted. Answers should be given on the separate answer sheet provided.
1.  The diagram below shows some protein filaments in muscle. Which protein is labelled with the letter P? P 4. The following statements refer to respiration: 1 2 3 4 Carbon dioxide is released Occurs during aerobic respiration The end product is pyruvic acid The end product is lactic acid

Which statements refer to glycolysis? A Actin B Adenine C Adenosine D Myosin A B C D 1 and 4 2 and 3 1 and 3 2 and 4

2. The following cell components are involved in the synthesis and secretion of an enzyme. 1 Golgi apparatus

5. The diagram below represents a cross-section of a membrane magnified 2 million times.

2 Ribosome 3 Cytoplasm 4 Endoplasmic reticulum 16 mm


Which of the following identifies correctly the route an amino acid molecule would follow as an enzyme is synthesised and secreted? A B C D 3 2 1 4 2 4 3 1 3 2 4 1 3 4 2 1

What is the actual width of the membrane? 1 nm = 1 × 10–6 mm A B D 1·6 nm 3·2 nm 16·0 nm

C 8·0 nm

3. How many adenine molecules are present in a DNA molecule of 4000 bases, if 20% of the base molecules are cytosine? A B C 400 600 800

6.  During the manufacture of protein in a cell, the synthesis of mRNA occurs in the A nucleus B ribosomes C D Golgi body endoplasmic reticulum.

D 1200


7. The following diagram shows some stages in the synthesis of part of a polypeptide. Tyrosine Amino acid tRNA

9. In the formation of gametes when does DNA replication occur? A B C D At the separation of chromatids As homologous chromosomes pair Before the start of meiosis At the end of the first meiotic division



10. Identical twins can result from A B C a haploid egg fertilised by a single sperm a haploid egg fertilised by two identical sperm a diploid egg fertilised by a single sperm fertilised by two

DNA Identify the triplet codes for the amino acid tyrosine. On mRNA A B C D ATA UAU AUA ATA On tRNA UAU AUA UAU TAT


D two haploid eggs identical sperm.

11. The diagram below represents a stage in the division of a cell.

8. Visking tubing is selectively permeable. In the experiment shown below, to demonstrate osmosis, the following results were obtained. Initial mass of visking tubing + contents = 10·0 g Mass of visking tubing + contents after experiment = 8·2 g Which line of the table identifies correctly the type of division and the number of chromosomes? Solution S Visking tubing A Solution R B C D The results shown would be obtained when A B C D R is a 5% salt solution and S is a 10% salt solution R is a 10% salt solution and S is a 5% salt solution R is a 10% salt solution and S is water R is a 5% salt solution and S is water. Type of division mitosis mitosis meiosis meiosis Number of chromosomes 8 4 8 4


12. Phenylketonuria autosomal gene.






 A man and a woman, who are unaffected, have an affected child.  What is the probability that their next child will be affected? A 25% B 50% D 100%

16. The graph below shows the changes which occur in a body’s food stores during four weeks of food deprivation.

10 protein 8 Mass of stored food (kg)

C 75%


13. The offspring from a mother who is homozygous for blood group A and a father who is heterozygous for blood group B, will have a blood group which is A B C D AB or A AB or B A or B A or O.



2 glycogen 0 0 1 2 3 4

Weeks of food deprivation 14. A function of the interstitial cells in the testes is to produce A sperm B testosterone C D seminal fluid follicle stimulating hormone (FSH). 15. Which of the following is the sequence of events following fertilisation? A Cleavage Differentiation Implantation Differentiation [Turn over Implantation Which of the following conclusions can be drawn from the graph? A B The glycogen food store decreases at the fastest rate during week one. Between weeks three and four the body gains most energy from protein.

C Each food store decreases at a constant rate during week one. D Between weeks one and four the body only gains energy from lipid and protein.

B Implantation Cleavage C D Differentiation Cleavage

Cleavage Implantation Differentiation

17. The graph below shows the growth in length of a human fetus before birth.

19. The effect on the kidney of a high concentration of antidiuretic hormone (ADH) in the blood is to A increase tubule permeability increases water reabsorption B decrease tubule permeability prevents excessive water loss C which which

400 Length of fetus (mm) 300

200 100 0 0 1 2 3 4 5 6 7 8 9 Age of fetus (months)

increase glomerular filtration rate which increases urine production

D decrease glomerular filtration rate which reduces urine production.

20. Compared to the blood in the renal artery, the blood in the renal vein has a higher concentration of A oxygen B carbon dioxide C glucose D urea.

What is the percentage increase in length of the fetus during the final 4 months of pregnancy? A 33·3 B 60·0 C 62·5 D 150·0

21. The graph below records the body temperature of a woman during an investigation in which her arm was immersed in warm water for 5 minutes. 37·1 Body temperature (°C) 37·0 36·9 36·8 36·7 0 5 10 15 20 25 30

18. The sperm counts of a sample of men taken between 1940 and 2000 are shown in the graph below. 150 Sperm count (million/cm3)



Time (minutes) Arm immersed in warm water during this period By how much did the temperature of her body vary during the 30 minutes of the investigation? Page six A B C D 2·7 °C 0·27 °C 2·5 °C 0·25 °C

0 1940

1960 Year



What is the average reduction in sperm count per year? A B C D 0·67 million/cm3/year 0·75 million/cm3/year 0·92 million/cm3/year 45 million/cm3/year


22. The flow chart below shows how the concentration of glucose in the blood is regulated. Blood glucose concentration rises Pancreas secretes less of compound X and more of compound Y Liver converts glucose to insoluble carbohydrate Blood glucose concentration falls

Which line identifies correctly the compounds X and Y? Compound X A B C D glycogen insulin glucagon insulin Compound Y insulin glycogen insulin glucagon 26. The rewarding of patterns of behaviour which approximate to desired behaviour is called A generalisation B discrimination C extinction D shaping. 24. The following is a list of body parts: 1 tongue 2 eyebrows 3 hands 4 eyes. Which of these body parts can be used in non-verbal communication? A B C D 3 only 2 and 4 only 2, 3 and 4 only 1, 2, 3 and 4 [Turn over 27. In the nitrogen cycle, which of the following processes is carried out by nitrifying bacteria? The conversion of A B C D nitrate to ammonia nitrogen gas to ammonia ammonia to nitrate nitrogen gas to nitrate.

23. The somatic nervous system controls the A B C D skeletal muscles heart and blood vessels endocrine glands muscular wall of the gut.

25. An athlete has a much better chance of achieving a “personal best” time in a race rather than in training because of A internalisation B deindividuation C identification D social facilitation. Page seven


28. The graph below shows the time taken by a student to complete a finger maze, over a number of trials, and the number of errors at each trial. Key errors time taken



Which of the following statements is correct? A B C D The fastest time to complete the maze correctly is 4 seconds. The time taken at trial 5 is 20 seconds. When the number of errors is 10, the time taken is 25 seconds. The number of errors decreased with each subsequent trial.

29. The bar chart below shows the percentage loss in yield of four organically grown crops, as a result of the effects of weeds, disease and insects. 40 35 30 Weeds % Yield Loss 25 20 Disease 15 10 5 0 A B Crop Which crop is likely to show the greatest increase in yield if herbicides and insecticides were applied? C D Insects KEY


30. The graph below shows how the UK diet changed between 1988 and 1998.

g/person/week 0 Dairy products Vegetables and vegetable products Cereal products Fruit and fruit products Meat and meat products 500 1000 1500 2000 2500

1988 1998 Which of the following conclusions can be drawn from the data? A B C D People ate more food in 1998 than in 1988. People ate less food in 1998 than in 1988. People ate a greater variety of food in 1998 than in 1988. People ate a lesser variety of food in 1998 than in 1988.

Candidates are reminded that the answer sheet MUST be returned INSIDE the front cover of this answer booklet.


SECTION B All questions in this section should be attempted. All answers must be written clearly and legibly in ink.


1. The diagram below shows a cell from the lining of a kidney tubule.

mitochondrion glomerular filtrate


(a)  This cell is adapted to reabsorb substances from the glomerular filtrate by active transport.

(i) What is meant by active transport?


(ii) Describe how this cell is adapted for active transport.


(iii) Explain how this cell is adapted for reabsorption.


(b)  Name the component of the membrane which is involved in active transport. 1 (c)  The diagram below shows one of the mitochondria from this kidney tubule cell in greater detail.


X (i)  Complete the table below by naming the labelled regions of the mitochondrion and the stage of respiration that occurs there Region Name Respiration stage


2 (ii) Suggest how the structure of a mitochondrion from a less active cell would differ from the structure of the mitochondrion shown. Give a reason for your answer. Structural difference


The diagram below shows how the immune system responds to a polio virus in a vaccine.

polio viruses cell division cell Q

cell P

memory cell


(a) What type of immunological response involves the production of antibodies?
(b) (i) Name cell Q. 1

1 (ii) Describe two functions of cell P that are shown in the diagram.
1 2 (c) Describe the role of memory cells in the immune system.
2. (continued) (d)  Explain why vaccination against polio would not provide immunity against
the measles virus. (e) In an emergency, ready-made antibodies can be injected into an individual. (i) Name the type of immunity that this gives. (ii) State one advantage and one disadvantage of this type of immunity. Advantage Disadvantage 2 1

3. Duchenne’s muscular dystrophy is an inherited condition in which muscle fibres
gradually degenerate. The condition is sex-linked and caused by a recessive allele.  The family tree below shows the inheritance of the condition through three generations of a family. Grandparents P R Q S

Unaffected female Carrier female Unaffected male

T (a)


Affected male

(i)  Using the symbols D and d to represent the alleles, state the genotypes of individuals R and S. R S 1

(ii) What percentage of the grandsons have muscular dystrophy?
(iii) Sisters T and U each go on to have a son.


For each sister, state the percentage chance of her son having muscular

(b)  In humans there is a gene which codes for the essential muscle protein


When this gene is altered, dystrophin is not produced. An individual with Duchenne’s muscular dystrophy cannot make dystrophin. (i) What general term is used to describe a gene alteration? 1

(ii) How might the structure of the gene which codes for dystrophin be
altered? (iii) Why does this altered gene fail to produce dystrophin? 1 (c)  Where conditions such as Duchenne’s muscular dystrophy exist in a family, the family history can be used to determine the genotypes of its individual members. What term is used for this process? 1 1

4. (a)  Photographic film consists of a clear sheet of plastic coated with
chemicals that give it a dark appearance. The chemicals are stuck to the plastic by the protein gelatine.

An investigation was carried out using photographic film and the
enzyme trypsin which digests protein.

 A piece of photographic film was placed in a test tube containing a solution of
trypsin, as shown in Figure 1 below.


The time taken for the film to turn clear was measured.

 The procedure was then repeated using different concentrations of trypsin solution. Figure 1 The results of the investigation are shown in Table 1 below. Table 1 Trypsin concentration (%) 1 trypsin solution photographic film 2 3 4 5 6 Time taken for film to clear (s) 112 102 93 84 84 84

(i)  Explain why the photographic film turns clear in this investigation.


(ii)  List two variables which would have to be kept constant throughout the
investigation. 1 2 2

(iii) How could the reliability of the results of this investigation be


4. (a) (continued) (iv) Plot a line graph to illustrate the results of the investigation.
(Additional graph paper, if required, can be found on Page thirty-six)



(v)  Explain why the time taken for the film to clear changed as trypsin
concentration increased from 1% to 4%. (vi)  Suggest why there was no change in the time taken to clear the film at trypsin concentrations above 4%. 1 1


(b)  An inactive form of trypsin called trypsinogen is produced and released from the pancreas. Trypsinogen is then converted to trypsin by another enzyme. (i) In which part of the digestive system does activation of trypsin occur?

(ii) Why are some enzymes such as trypsin produced in an inactive form? (iii) Apart from other enzymes, name another type of molecule that can act
as an enzyme activator.

The diagram shows a section through the heart and two areas, X and Y, which
help to coordinate the heart beat. X


valve Z



(i) Name structures X and Y. X Y 1


(ii) Electrical impulses travel from X to Y.

What is happening to the heart during this time?

(iii)  Draw arrows on the diagram to show the pathway taken by electrical
impulses produced by structure Y.



(i) Name valve Z. 1

(ii) During which stage of the cardiac cycle is valve Z closed?


6. The graph below shows the concentrations of two ovarian hormones in a woman’s
blood during her menstrual cycle.

Concentration of hormone (units)oestrogen hormone X





16 Time (days)




(a) Name hormone X. (b) What effect does oestrogen have on the following structures? (i) The uterus between days 4 and 12 in the cycle. (ii) The pituitary gland on day 12 of the cycle. (c) Describe one way in which the graph would be different if the woman became pregnant during this cycle. 1 1 1 1

6. (continued)
(d)  The diagrams below show sections through two structures found in the ovary at different times in the menstrual cycle.



(i) Name structures P and Q. P Q (ii) What key event in the menstrual cycle occurs before P develops into Q? 1 1


7. The graph below shows changes that occurred in a man’s breathing when he
inhaled air containing different concentrations of carbon dioxide. Key volume of each breath breathing rate 2400 2200 2000 Volume of each breath (cm3) 1800 1600 1400 1200 1000 800 600 400 200 0 1 2 3 4 5 6 7 32 30 28 26 24


22 Breathing rate (breaths/min) 20 18 16 14 12 10

Carbon dioxide concentration of inhaled air (%)

(a)  Use data from the graph to describe the changes that occurred in the man’s
breathing when the carbon dioxide concentration of inhaled air increased from 0 to 3%.


(b)  What was the man’s breathing rate when the volume of each breath was
1500 cm3?



(c)  Calculate the volume of air inhaled in one minute when the carbon dioxide concentration was 2%. Space for calculation



(d) (i)  Predict what the volume of each breath would have been if a carbon
dioxide concentration of 7% had been used.

Volume of each breath
(ii)  Suggest why the increase in the volume of each breath becomes less at carbon dioxide concentrations above 4%.

1 (e)  On average there is 0·04% carbon dioxide in inhaled air and 4% carbon dioxide in exhaled air. Explain why this change in carbon dioxide concentration occurs.
The diagram below represents the liver and some associated structures. hepatic artery hepatic vein

(a)  Draw arrows beside each of the three blood vessels to show the direction of
blood flow. (b) (i) Name the liquid stored in the gall bladder.



(ii) State one function of this liquid and explain how it aids digestion.
Function Explanation (c) Name one substance that is stored in
(a)  Explain how the maximum number of interconnections between neurones is achieved within the cerebrum.


2 (b) What is the function of the corpus callosum?

1 (c) (i) Which division of the nervous system is linked to the medulla?

(ii) Describe how this division of the nervous system controls heart rate.
1 1


10. The information in the table below refers to the development of walking by infant
boys. Stage of development Description of behaviour Age (weeks) at which behaviour develops Earliest 1 2 3 4 5 6 7 Rolls over Sits up without support Crawls 9 16·5 21 Latest 23 32·5 38 43 49 54 57·5

Pulls up and stands holding on 23 to furniture Walks holding on to furniture Stands unsupported Walks alone 28·5 35·5 44·5

(a) Assuming a normal pattern of distribution, predict by what age 50% of boys
would be expected to walk alone. Space for calculation



(b) Identify all the stages in the development of walking that boys could be at
when they are 36 weeks old. 1 2 3 4 5 6 7 1 Tick the correct boxes

(c) Suggest two reasons why a boy might still only be crawling when, at the same
age, his elder brother could stand unsupported. 1 2 1
(i)  What term describes the development of a behaviour which follows a set sequence of stages?

(ii)  Describe the change which occurs in the nervous system that
allows children to go through the stages of development leading to walking.


11. An investigation was carried out into the effect that the meaning of words has on
the ability to recall them from short and long-term memory. Two groups of people were each shown lists of five words for 30 seconds.  Group 1 was shown words with related meanings while group 2 was shown words with unrelated meanings.


List of words with related meanings – large, big, great, huge, wide. List of words with unrelated meanings – late, cheap, rare, bright, rough.

 Immediately after the 30 seconds, the people in both groups were asked to write down, in the correct order, the words that they had been shown.  Everyone was then asked to read a book for one hour and told that they would be asked questions about it afterwards.  Instead, after the hour had passed, everyone was again asked to write down, in the correct order, the words that they had been shown in their original list. The results of the investigation are shown in the table below. Correct responses immediately after reading the words (%) 96 96


Meaning of words shown related unrelated

Correct responses after reading the book for one hour (%) 54 78

1 2

(a) List two ways in which the investigators could minimise variation between the two groups of people. 1 2 1

(b)  What aspect of memory explains the high percentage of correct responses immediately after reading the words?


(c) Suggest why the groups were asked to read a book during the investigation.
(d) State two conclusions that can be drawn from the results of this investigation.

1 2
12. The diagram below shows the changes that affect the population of a country as it
undergoes development. Key Birth rate Death rate Population size Stage 1 high Stage 2 Stage 3 high

(a) (i)  Describe the country’s birth rate at stage 2 and stage 3 during its development.
1 (ii)  Use information from the diagram to explain why the population size increases rapidly and then starts to level off during stage 2. 2

12. (a) (continued)
(iii) Suggest two factors which may contribute to the change in the death rate during stage 2. 1 2 1

(b) The increasing world population requires an increased supply of food.
(i)  Pesticides are chemicals which can be used to increase food supply. However, their use can lead to instability in food webs.

Explain this effect.

1 (ii)  Other chemicals, such as fertilisers, are also used to increase food production. Name another method of increasing food production that does not involve chemicals. 1

(c)  When fertilisers are used in agriculture they can pollute rivers and lochs
causing algal blooms. (i) What is an algal bloom?

(ii) Describe the effects an algal bloom might have on a loch.


SECTION C Both questions in this section should be attempted. Note that each question contains a choice. Questions 1 and 2 should be attempted on the blank pages which follow. Supplementary sheets, if required, may be obtained from the Invigilator. Labelled diagrams may be used where appropriate. 1. Answer either A or B. A Give an account of the carbon cycle under the following headings: (i) natural uptake and release of carbon; (ii) disruption of the carbon cycle by human activities.

OR B  Give an account of the nervous system under the following headings: (i) the role of neurotransmitters at the synapse; (ii) converging and diverging neural pathways. 6 4 (10)

In question 2, ONE mark is available for coherence and ONE mark is available for relevance. 2. Answer either A or B. A OR B Describe involuntary mechanisms of temperature control. (10) Describe the exchange of substances between plasma and body cells. (10)