Cambridge A Level Biology 9700 — 2013 May/June Paper 1 · Variant 3

Question 1

1 An electron microscope has a higher resolution than a light microscope. Which is a result of the higher resolution? A the ability to produce larger images of cells B the ability to see cristae in mitochondria C the ability to see mRNA in all cells D the ability to see the nucleus in eukaryotes

Accepted Answer

B

Question 2

2 The diagram shows a chloroplast drawn from an electronmicrograph. X Y The length of the chloroplast from X to Y is 5000 nm. What is the magnification of the drawing of the chloroplast? A ×100 B ×1000 C ×10 000 D ×100 000

Accepted Answer

C

Question 3

3 Eyepiece graticules and stage micrometers are used to measure cells. Which is the correct reason why an eyepiece graticule is calibrated? A An eyepiece graticule can be used to make measurements. B An eyepiece graticule is magnified by the objective lens. C An eyepiece graticule magnifies the specimen. D An eyepiece graticule makes comparisons.

Accepted Answer

A

Question 4

4 The electronmicrograph shows part of two cells. W X Y Which of the labelled features enable these cells to be identified as eukaryotic? A W only B X only C W and X only D W, X and Y

Accepted Answer

A

Question 5

5 When mucus is secreted from a goblet cell in the trachea, these events take place. 1 addition of carbohydrate to protein 2 fusion of the vesicle with the plasma membrane 3 secretion of a glycoprotein 4 separation of a vesicle from the Golgi apparatus What is the sequence in which these events take place? A 1 → 4 → 2 → 3 B 1 → 4 → 3 → 2 C 4 → 1 → 2 → 3 D 4 → 1 → 3 → 2

Accepted Answer

A

Question 6

6 What is a function of the smooth endoplasmic reticulum? A antibody synthesis B enzyme synthesis C protein synthesis D steroid synthesis

Accepted Answer

D

Question 7

7 Two solutions, 1 and 2, one containing starch and sucrose, and the other containing glucose and protein, were tested with a variety of reagents to confirm their identity. The table shows the conclusions from the results recorded for the various tests. Which row identifies the two solutions? boil with boil with add iodine Benedict’s add biuret Benedict’s solution solution after solution solution acid hydrolysis 1 2 1 2 1 2 1 2 key A + – + – – + – + + = biological molecule present B – + + – + – – + – = biological C + – – + + – – + molecule absent D – + + – + + + –

Accepted Answer

C

Question 8

8 The structural formula of a carbohydrate molecule can be shown as: H C O H C OH HO C H HO C H H C OH CH2OH Which of the molecules could be represented by this formula? 1 β-glucose 2 deoxyribose 3 ribose A 1 only B 1 and 2 only C 1 and 3 only D 2 and 3 only

Accepted Answer

A

Question 9

9 The diagram shows part of a molecule of a carbohydrate formed by glucose. What is the name of the molecule? A amylose B cellulose C glycogen D starch

Accepted Answer

C

Question 10

10 A naturally occurring polysaccharide is a branched chain of α-glucose. The straight parts of the molecule are linked by α-1, 6 glycosidic bonds with a small number of branches which are linked by either an α-1, 3 glycosidic bond or an α-1, 4 glycosidic bond. Which polysaccharide has a structure most similar to that described? A amylopectin B amylose C cellulose D glycogen

Accepted Answer

A

Question 11

11 Which molecule has properties that are not dependent on hydrogen bonds? A cellulose B glycogen C haemoglobin D water

Accepted Answer

B

Question 12

12 What occurs during protein denaturation by extremes of pH? 1 breakage of peptide bonds leading to loss of shape of active site 2 disruption of existing ionic bonds between amino acid R-groups 3 loss of α-helical regular arrangement of amino acids 4 loss of protein tertiary structure resulting in loss of function A 1, 2, 3 and 4 B 2, 3 and 4 only C 1 and 3 only D 2 and 4 only

Accepted Answer

B

Question 13

13 When the ice on the surface of a pond melts, which changes benefit the ecosystem in the pond? 1 The melted water sinks to the bottom of the pond. 2 The water from the bottom of the pond brings dissolved minerals to the surface. 3 Warmer water dissolves more oxygen for the aerobic organisms. A 1, 2 and 3 B 1 and 2 only C 1 and 3 only D 2 and 3 only

Accepted Answer

B

Question 14

14 How does increasing substrate concentration affect the rate of an enzyme-catalysed reaction in the presence of a competitive inhibitor? A The rate of the reaction decreases. B The rate of the reaction decreases initially and then recovers. C The rate of the reaction increases. D The rate of the reaction is not affected.

Accepted Answer

C

Question 15

15 Four students investigated the effect of catalase on hydrogen peroxide. Each student started a digital clock at the beginning of the experiment and stopped the clock after 25 bubbles had been counted. The time recorded on the digital clock is shown below. hours minutes seconds hundredths 00 01 33 54 Which student recorded the results to the best level of precision for the apparatus used? student time recorded A 1.34 minutes B 1 minute 33.54 seconds C 94 seconds D 93.54 seconds

Accepted Answer

C

Question 16

16 Which of the following can decrease the fluidity of the cell surface membrane? 1 double bonds between carbon atoms in the fatty acid chains 2 cholesterol 3 fatty acids having longer chains A 1, 2 and 3 B 1 and 2 only C 2 and 3 only D 3 only

Accepted Answer

D

Question 17

17 Which process would allow the movement of large protein molecules out of the cell? A active transport B exocytosis C facilitated diffusion D phagocytosis

Accepted Answer

B

Question 18

18 Strips of potato tissue were immersed in distilled water or in sucrose solutions of different concentrations. The graph shows the percentage change in length of the potato tissue over time. 20 distilled water 10 0.1 mol dm _3 sucrose solution percentage change in 0 length _10 _3 0.5 mol dm sucrose solution _20 0 1 2 3 4 5 time / hours Which row correctly shows how the water potentials of the distilled water and sucrose solutions differ from the initial water potential of the potato tissue? distilled 0.1 mol dm–3 0.5 mol dm–3 water sucrose solution sucrose solution A less negative less negative more negative B less negative more negative more negative C more negative less negative less negative D more negative more negative less negative

Accepted Answer

A

Question 19

19 Uncontrolled cell division of cancer cells forms tumours. Which statement describes the difference between a cancer cell and a normal cell? A Cancer cells do not undergo cytokinesis. B Cancer cells do not have metaphase. C Cancer cells have a shorter interphase. D Only cancer cells have mutated DNA.

Accepted Answer

C

Question 20

20 The diagram shows a cell nucleus in prophase of mitosis. Which statement describes the chromosomes found in each daughter nucleus immediately following division of this cell by mitosis? A 2 chromosomes, each consisting of 2 chromatids B 4 chromosomes, each consisting of 2 chromatids C 8 chromosomes, each containing 1 molecule of DNA D 4 chromosomes, each containing 1 molecule of DNA

Accepted Answer

D

Question 21

21 Gene mutations in either the BRCA71 or the BRCA2 genes are responsible for the majority of

hereditary breast cancer in humans.

The proteins produced by the two genes migrate to the nucleus where they interact with other
proteins, such as those produced by the tumour suppressor gene, p53 and the DNA repair gene,

RADS1.

Which combination of gene activity is most likely to result in breast cancer?

gene

OAS. 53 RAD51
A Vv Vv J
B Vv V x
c V x J
D x x x

key
/ = gene produces normal protein
X =gene produces abnormal protein

or no protein

Accepted Answer

D

Question 22

22 One gene provides the code for the production of which molecule? A amino acid B DNA C nucleotide D polypeptide

Accepted Answer

D

Question 23

23 A polypeptide has the amino acid sequence glycine – arginine – lysine – serine. The table gives possible tRNA anticodons for each amino acid. amino acid tRNA anticodons arginine UCC  GCG glycine CCA  CCU lysine UUC  UUU serine AGG  UCG Which sequence of bases on DNA would code for the polypeptide? A CCACGCAAGAGC B CCTTCCTTCTCG C GGAAGGAAAAGC D GGTTGGTTGTGC

Accepted Answer

B

Question 24

24 What is the minimum number of hydrogen bonds in a length of DNA containing 700 nucleotides? A 350 B 700 C 1050 D 1400

Accepted Answer

B

Question 25

25 The diagram shows part of a transverse section of a leaf. Where does evaporation of water occur during transpiration? A D C B

Accepted Answer

D

Question 26

26 The diagram shows a xerophytic leaf in different conditions, P and Q. X X P Q Which statements describe the difference between the cells in layer X in conditions P and Q? 1 More negative water potential in P than Q. 2 More cells plasmolysed in P. 3 Cells less turgid in Q. 4 Water potential becomes zero in Q. A 1, 2 and 3 only B 1 and 2 only C 2 and 4 only D 3 and 4 only

Accepted Answer

B

Question 27

27 A potometer can be used to measure transpiration rates in a plant. Why is the plant stem cut under water before attaching to the potometer? A to maintain the turgidity of the xylem vessels B to prevent collapse of the xylem vessels C to stop air entering the xylem vessels D to stop water loss from the xylem vessels

Accepted Answer

C

Question 28

28 Three solutions, with different water potentials (ψ) are listed. 1 cortex cell solution 2 endodermal cell solution 3 root hair cell solution Which row has the solutions in order from the least negative ψ to the most negative ψ? highest ψ lowest ψ A 1 2 3 B 2 1 3 C 3 2 1 D 3 1 2

Accepted Answer

D

Question 29

29 The diagram shows the pressure changes in various structures of the right side of the heart during the cardiac cycle. pressure X / kPa 0 0 0.2 0.4 0.6 0.8 time / s Which structure is represented by letter X? A pulmonary artery B right atrium C right ventricle D vena cava

Accepted Answer

A

Question 30

30 The trace represents the electrical activity of the heart during a single heart beat. R T P Q S Which letters identify the flow of current through the atria and the recovery of the ventricle walls? A P and R B P and T C Q and R D Q and S

Accepted Answer

B

Question 31

31 Which row describes the changes in the properties of haemoglobin as a result of the Bohr effect? affinity for oxygen oxygen dissociates by haemoglobin from haemoglobin A higher less readily B higher more readily C lower less readily D lower more readily

Accepted Answer

D

Question 32

32 Humans have a double circulation system. What does the term ‘double circulation’ mean? A The blood circulates separately in the two sides of the heart. B The blood passes twice through the heart during one complete circulation. C The heart has two of each chamber; atria and ventricles. D The heart beat has a double sound caused by the two sets of valves closing.

Accepted Answer

B

Question 33

33 The photomicrograph shows a section through part of a bronchus wall. X What is the function of the tissue labelled X? A contracts to constrict the airway B helps to widen the airway after an allergic reaction C produces mucus to trap dust particles and bacteria D supports the airway to prevent collapse

Accepted Answer

D

Question 34

34 Why is the inner lining of the bronchiole folded? A to allow for expansion during breathing B to facilitate gaseous exchange C to increase the surface area D to trap foreign particles

Accepted Answer

A

Question 35

35 What are the effects of carbon monoxide and nicotine on the cardiovascular system? carbon monoxide nicotine A combines with haemoglobin increases blood pressure B combines with haemoglobin reduces heart rate C reduces blood pressure increases heart rate D reduces heart rate combines with haemoglobin

Accepted Answer

A

Question 36

36 Some antibiotics are used in animal feed to reduce disease. What explains why these antibiotics should not be used in the treatment of human diseases? A Humans may be allergic to these antibiotics. B Human cells may stop responding to these antibiotics. C Pathogenic bacteria may develop resistance to these antibiotics. D Useful gut bacteria may be killed by these antibiotics.

Accepted Answer

C

Question 37

37 Which statement about both B-lymphocytes and T-lymphocytes is correct? A They become active only when a specific antibody binds to their surface receptor. B They divide to form clones when meeting an antitoxin in a cell. C They produce memory cells to respond to an antigen when exposed in the future. D They release hormone-like cytokines which stimulate release of antibodies.

Accepted Answer

C

Question 38

38 Which uses energy to produce its own food supply from inorganic compounds? A autotroph B consumer C heterotroph D saprotroph

Accepted Answer

A

Question 39

39 Two different ecosystems, X and Y, were compared. Both ecosystems are the same size and both have the same climate. The results of the comparison are shown in the table below. ecosystem X ecosystem Y greater number of trophic levels fewer number of trophic levels lower proportion of decomposers higher proportion of decomposers dominant producer is smaller dominant producer is larger and non-woody and woody has a smaller fluctuation has a larger fluctuation in environmental temperature in environmental temperature has less oxygen has more oxygen Using the information in the table, which statements are a valid suggestion concerning X and Y? 1 A greater percentage of primary producers are likely to be consumed by primary consumers in X than in Y. 2 X could be a marine aquatic ecosystem and Y could be a terrestrial ecosystem. 3 Energy losses between trophic levels are likely to be lower for X than for Y. 4 There is likely to be a higher rate of photosynthesis and production of organic matter in X than in Y. A 2 and 4 only B 1, 2 and 3 only C 1, 3 and 4 only D 1, 2, 3 and 4

Accepted Answer

D

Question 40

40 The diagram shows the flow of energy in a food web. Which represents the decomposers? A D B C

Accepted Answer

A

Question paper16 pages

Mark scheme2 pages

Questions as text

Q1 · An electron microscope has a higher resolution than a light microscope

Q2 · The diagram shows a chloroplast drawn from an electronmicrograph

Q3 · Eyepiece graticules and stage micrometers are used to measure cells

Q4 · The electronmicrograph shows part of two cells

Q5 · When mucus is secreted from a goblet cell in the trachea, these events take place

Q6 · What is a function of the smooth endoplasmic reticulum?

Q7 · Two solutions, 1 and 2, one containing starch and sucrose, and the other containing…

Q8 · The structural formula of a carbohydrate molecule can be shown as: H C O H C OH HO C H HO…

Q9 · The diagram shows part of a molecule of a carbohydrate formed by glucose

Q10 · A naturally occurring polysaccharide is a branched chain of α-glucose

Q11 · Which molecule has properties that are not dependent on hydrogen bonds?

Q12 · What occurs during protein denaturation by extremes of pH?

Q13 · When the ice on the surface of a pond melts, which changes benefit the ecosystem in the…

Q14 · How does increasing substrate concentration affect the rate of an enzyme-catalysed…

Q15 · Four students investigated the effect of catalase on hydrogen peroxide

Q16 · Which of the following can decrease the fluidity of the cell surface membrane?

Q17 · Which process would allow the movement of large protein molecules out of the cell?

Q18 · Strips of potato tissue were immersed in distilled water or in sucrose solutions of…

Q19 · Uncontrolled cell division of cancer cells forms tumours

Q20 · The diagram shows a cell nucleus in prophase of mitosis

Q21 · Gene mutations in either the BRCA71 or the BRCA2 genes are responsible for the majority…

Q22 · One gene provides the code for the production of which molecule?

Q23 · A polypeptide has the amino acid sequence glycine – arginine – lysine – serine

Q24 · What is the minimum number of hydrogen bonds in a length of DNA containing 700…

Q25 · The diagram shows part of a transverse section of a leaf

Q26 · The diagram shows a xerophytic leaf in different conditions, P and Q

Q27 · A potometer can be used to measure transpiration rates in a plant

Q28 · Three solutions, with different water potentials (ψ) are listed

Q29 · The diagram shows the pressure changes in various structures of the right side of the…

Q30 · The trace represents the electrical activity of the heart during a single heart beat

Q31 · Which row describes the changes in the properties of haemoglobin as a result of the Bohr…

Q32 · Humans have a double circulation system

Q33 · The photomicrograph shows a section through part of a bronchus wall

Q34 · Why is the inner lining of the bronchiole folded?

Q35 · What are the effects of carbon monoxide and nicotine on the cardiovascular system?

Q36 · Some antibiotics are used in animal feed to reduce disease

Q37 · Which statement about both B-lymphocytes and T-lymphocytes is correct?

Q38 · Which uses energy to produce its own food supply from inorganic compounds?

Q39 · Two different ecosystems, X and Y, were compared

Q40 · The diagram shows the flow of energy in a food web

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