Cambridge A Level Biology 9700 — 2013 May/June Paper 1 · Variant 2

Question 1

1 A light microscope is used to observe two membranes that are 200 nm apart. How far apart are the membranes when the objective lens is changed from low power (×40) to high power (×400)? A 2 µm B 20 µm C 200 nm D 2000 nm

Accepted Answer

C

Question 2

2 The electronmicrograph is of a chloroplast. The length of the chloroplast along the line shown is 80 mm. The actual length of the chloroplast is 10 µm. What is the magnification of the chloroplast? A ×8 × 102 B ×8 × 103 C ×8 × 104 D ×8 × 106

Accepted Answer

B

Question 3

3 The diagram below is drawn from an electronmicrograph of an animal cell. Which represents the same cell, seen under a light microscope at ×400 magnification?

Accepted Answer

C

Question 4

4 Which features enable an organism to be identified as a prokaryote? 1 cell wall 2 circular DNA 3 nucleus 4 ribosomes A 2 only B 3 only C 1 and 4 only D 2 and 4 only

Accepted Answer

A

Question 5

5 The diagram shows an electronmicrograph of a typical animal cell. X What is the function of the membrane system labelled X? A lipid synthesis B lipid synthesis and transport C protein synthesis D protein synthesis and transport

Accepted Answer

D

Question 6

6 An animal cell and a plant cell are placed in distilled water. The animal cell swells and bursts, while the plant cell swells but does not burst. What accounts for this difference? A Animal cells have no cell wall. B Animal cells have no vacuole. C Plant cell surface membranes are partially permeable. D Plant cell walls are freely permeable.

Accepted Answer

A

Question 7

7 The R groups (side chains) of amino acids can be hydrophobic, hydrophilic, acidic or basic. The diagram shows four different amino acid R groups. COOH NH2 OH CH3 CH2 (CH2)4 CH2 Ala Asp Lys Ser Which row is correct for these amino acid R groups? hydrophobic hydrophilic acidic basic A Ala Ser Asp Lys B Ala Ser Lys Asp C Asp Lys Ser Ala D Asp Ser Lys Ala

Accepted Answer

A

Question 8

8 Which describes the emulsion test for the presence of lipids? A Add ethanol and shake. B Add ethanol, pour into water and shake. C Add water and shake. D Add water, pour into ethanol and shake.

Accepted Answer

B

Question 9

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

Accepted Answer

B

Question 10

10 The diagram shows part of a molecule of glycogen. How does the molecule differ from a molecule of amylose? A Amylose has only α-1,4 glycosidic bonds. B Amylose has only β-1,4 glycosidic bonds. C Amylose has α-1,6 glycosidic bonds with 1,4 linkages forming branches. D Amylose has β-1,4 glycosidic bonds with 1,6 linkages forming branches.

Accepted Answer

A

Question 11

11 Which molecules contain a carboxyl group? 1 amino acid 2 glycerol 3 saturated fatty acid 4 unsaturated fatty acid A 1 and 2 only B 3 and 4 only C 1, 3 and 4 only D 2, 3 and 4 only

Accepted Answer

C

Question 12

12 The diameter of some atoms when they form bonds are given in the table. single bond double bond atom / nm / nm H 0.060 – O 0.132 0.110 N 0.140 0.120 C 0.154 0.134 The approximate length of the amino acid shown below was estimated using the figures in the table. R O H N C C O H H H 0.7 nm What would be the approximate length of a dipeptide formed using this amino acid? A 0.9 nm B 1.2 nm C 1.4 nm D 1.7 nm

Accepted Answer

B

Question 13

13 Which feature of water is least likely to affect the life of an animal in a tropical rain forest? A adhesion with other molecules B cohesion between water molecules C low viscosity D maximum density at 4 °C

Accepted Answer

D

Question 14

14 Two pairs of students each counted the number of bubbles of oxygen given off in a minute when investigating the effect of catalase from plant tissue on hydrogen peroxide. Each pair repeated the experiment five times and calculated the mean number of bubbles per minute. Which have correctly calculated the mean? raw data / number of bubbles minute-1 mean / number of student bubbles minute-1 1 8 10 11 9 8 9.2 2 8 10 11 9 8 9 3 21 18 6 17 19 16.2 4 21 18 6 17 19 18.8 A 1, 3 and 4 only B 1 and 4 only C 2 only D 3 only

Accepted Answer

C

Question 15

15 When investigating the rate of reaction of the enzyme lipase on the hydrolysis of triglycerides, the pH must be maintained at an optimum to prevent the lipase denaturing. What is the reason for this? A The addition of water molecules produced by hydrolysis increases pH. B The products of hydrolysis decrease the pH. C The products of hydrolysis increase the pH. D The removal of water molecules used in hydrolysis decreases pH.

Accepted Answer

B

Question 16

16 Which of the following can increase the fluidity of the cell surface membrane? 1 single 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 3 only C 2 and 3 only D 2 only

Accepted Answer

D

Question 17

17 The diagram shows a cell that produces protease enzymes. Which row is correct? enzymes released by ATP needed A endocytosis no B endocytosis yes C exocytosis no D exocytosis yes

Accepted Answer

D

Question 18

18 The diagram shows two identical plant cells. One plant cell is put into a solution with a water potential less negative than the cell contents. The other is put into a solution with a water potential more negative than the cell contents. What will happen to the appearance of each cell? water potential of solution water potential of solution surrounding cell less surrounding cell more negative than cell contents negative than cell contents A B C D

Accepted Answer

C

Question 19

19 Chromosome telomeres are essential for DNA replication and are not completely replaced during mitosis. A substance X is known that completely replaces telomeres during mitosis. What will be the effect of growing cells with and without substance X? with substance X without substance X A cells divide continually cell division eventually slows and stops B cells divide more rapidly cells divide continually C cell division eventually slows cell division stops immediately and stops D cell division stops immediately cells divide continually

Accepted Answer

A

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 8 chromosomes, each consisting of 4 chromatids B 8 chromosomes, each containing 1 molecule of DNA C 4 chromosomes, each consisting of 4 chromatids D 16 chromosomes, each containing 1 molecule of DNA

Accepted Answer

B

Question 21

21 Which features of mitosis ensure that the genetic constitution of the cell is maintained? 1 the position of the chromosomes on the equator of the spindle 2 the longitudinal division of the centromeres 3 the DNA of the parent cells replicates before mitosis begins 4 the pulling apart of the chromatids to opposite poles A 1, 2 and 3 only B 1, 2 and 4 only C 2, 3 and 4 only D 1, 2, 3 and 4

Accepted Answer

C

Question 22

22 What is the maximum number of hydrogen bonds in a length of DNA containing 700 nucleotides? A 350 B 700 C 1050 D 2100

Accepted Answer

C

Question 23

23 Which type of molecule is the end product of translation? A amino acid B mRNA C polypeptide D tRNA

Accepted Answer

C

Question 24

24 A polypeptide molecule contains the amino acid sequence: glycine – leucine – lysine – valine. The table shows DNA codes for these amino acids. glycine leucine lysine valine CCC GAA TTT CAA Which tRNA anticodons are needed for the synthesis of this polypeptide? A CCC   GAA   TTT   CAA B CCC   GAA   UUU   CAA C GGG   CUU   AAA   GUU D GGG   CUU   UUU   GUU

Accepted Answer

B

Question 25

25 Which plant cells do not contain a nucleus? 1 companion cells 2 sieve tube elements 3 xylem vessel elements A 1 and 2 only B 1 and 3 only C 2 and 3 only D 3 only

Accepted Answer

C

Question 26

26 The diagram shows three xerophytic leaves of the same type in three different conditions, P, R and S. layer X X X P R S Which description of the water potential of the cells in layer X is correct? water potential of cells in layer X P R S A less negative than R and S more negative than P and S more negative than P B less negative than S more negative than P less negative than P C more negative than R less negative than S less negative than R D more negative than R and S less negative than P more negative than P

Accepted Answer

A

Question 27

27 The diagram shows how sucrose is loaded into a sieve tube element. companion cell sieve tube element 1 hydrogen ions move out of the companion cell 3 sucrose molecules move into sucrose molecules move into sucrose molecules move into the sieve tube element the sieve tube element the sieve tube element hydrogen ions move into the companion cell 2 sucrose molecules move into the companion cell What type of transport is used to move the substances in steps 1, 2 and 3? 1 2 3 A active transport active transport diffusion B active transport facilitated diffusion diffusion C facilitated diffusion active transport active transport D facilitated diffusion facilitated diffusion active transport

Accepted Answer

B

Question 28

28 Halophytes are plants that can survive in regions where they are regularly exposed to sea water. Sea water has a water potential of approximately –2500 kPa. Which adaptation would you expect halophytes to show? A root hair cells with a very high water potential B root hair cells which accumulate salts and other solutes C a high density of stomata that are open most of the time D leaves that have a large surface area and a thick cuticle

Accepted Answer

B

Question 29

29 A number of different tissues occur in the walls of major blood vessels. Which row correctly identifies the main tissues found in the three layers of the wall of an artery? outer layer middle layer inner layer (tunica externa) (tunica media) (tunica intima) A collagen elastic endothelium B collagen muscle elastic C elastic collagen endothelium D elastic collagen muscle

Accepted Answer

A

Question 30

30 The diagram shows the pressure changes in various structures of the right side of the heart during the cardiac cycle. key pressure / kPa X Y Z 0 0 0.2 0.4 0.6 0.8 time / s Which structures are represented by the letters X, Y and Z? X Y Z A pulmonary artery right atrium right ventricle B right atrium pulmonary artery right ventricle C right ventricle pulmonary artery right atrium D right ventricle right atrium pulmonary artery

Accepted Answer

C

Question 31

31 Which statement is true for the Bohr effect? A As the partial pressure of carbon dioxide increases the dissociation curve becomes S- shaped (sigmoid). B At higher partial pressures of carbon dioxide and equal partial pressures of oxygen, the percentage saturation of haemoglobin with oxygen will be higher. C The carbon dioxide in the air prevents haemoglobin becoming fully saturated with oxygen during gas exchange in the lungs. D The release of oxygen from haemoglobin is more likely at higher partial pressures of carbon dioxide.

Accepted Answer

D

Question 32

32 Aortic stenosis is a heart valve disorder in which the aortic semi-lunar valve opening is narrow. Which effect could aortic stenosis have on heart structure and function? A The cardiac muscle of the left ventricle wall is thinned by blood leaking out of the left ventricle during ventricular diastole. B There is less cardiac muscle in the left ventricle and reduced diastolic blood pressure, caused by the smaller blood volume entering the left atrium. C The tendons of the heart valves are weakened by blood being forced back through the left atrio-ventricular (bicuspid) valve into the left atrium. D The wall of the left ventricle thickens, leading to an enlarged heart and inability to relax and fill completely during diastole.

Accepted Answer

D

Question 33

33 What can be observed about some of the tissues in a transverse section of a mammalian trachea? epithelium goblet cells cartilage A ciliated present in blocks B ciliated present in C-shaped rings C non-ciliated absent in blocks D non-ciliated absent in C-shaped rings

Accepted Answer

B

Question 34

34 There is a lot of epidemiological evidence linking smoking to disease and early death. Which is the best description of ‘epidemiological’? A Disease and deaths are not randomly distributed in small populations. B Disease and deaths are not randomly distributed in the whole population. C Disease and deaths are only randomly distributed in large populations. D Disease and deaths are randomly distributed in the whole population.

Accepted Answer

B

Question 35

35 Which row shows the effects of chronic bronchitis? lymph glands alveoli bronchi infection A destroyed damaged inflamed absent B destroyed inflamed scarred absent C swollen damaged scarred present D swollen inflamed inflamed present

Accepted Answer

C

Question 36

36 A country had fewer than 2.5 deaths per 100 000 people from TB in one year and the next year this rose to 25 deaths per 100 000. What may have contributed to this change? 1 decrease in contact tracing 2 increase in refugee camps 3 water supply contaminated by sewage A 1 and 2 only B 1 and 3 only C 2 and 3 only D 1, 2 and 3

Accepted Answer

A

Question 37

37 A graft of tissue, such as skin, from a different person is usually rejected by the body. Which statement about graft rejection is correct? A The graft is rejected by B-lymphocytes because they make and release antibodies which react with the surface antigens on the graft cells. B The graft is rejected by B-lymphocytes because T-lymphocytes are not stimulated to produce antibodies. C The graft is rejected by T-lymphocytes because the graft tissue causes T-lymphocytes to release antibodies. D The graft is rejected by T-lymphocytes because they circulate in the blood and can gather at the graft site.

Accepted Answer

D

Question 38

38 The diagram shows a simplified nitrogen cycle. nitrate P legume R Q ammonia S nitrogen nitrogen in primary consumers Which row shows the correct labels for P, Q, R and S? P Q R S A denitrification nitrogen decay of leaf ammonification by anaerobic fixation by tissue by by saprotrophic bacteria nitrifying saprotrophic fungi bacteria bacteria B lightning nitrogen decomposition decomposition action on soil fixation by using by root nodule nitrates nitrogen fixing nitrogenase bacteria bacteria enzyme C nitrification nitrification decay of leaf assimilation of by anaerobic using tissue by organic bacteria nitrogenase saprotrophic nitrogen enzyme fungi D reduction by nitrogen decomposition decay of urea anaerobic fixation by of organic by saprotrophic bacteria root nodule nitrogen bacteria bacteria

Accepted Answer

D

Question 39

39 Which statements about energy flow in ecosystems are correct? 1 All energy eventually leaves ecosystems in the form of heat. 2 The average energy transfer between trophic levels is 10 %. 3 The energy stored and lost from an ecosystem is equal to the energy input from the Sun. A 1, 2 and 3 B 1 and 2 only C 1 and 3 only D 2 and 3 only

Accepted Answer

A

Question 40

40 In many freshwater ecosystems, the availability of inorganic nitrogen compounds is a limiting factor for growth. This means that producers cannot grow as quickly as they could even though no other factor is limiting. Which statements about these ecosystems are correct? 1 Transfer of energy to higher trophic levels is also limited by availability of these nitrogen compounds. 2 Addition of excess nitrate compounds will benefit all organisms in the ecosystem. 3 The percentage of energy lost between trophic levels will be the same whether nitrogen compounds are limiting or not. 4 Addition of ammonium compounds will cause an increase in the numbers of nitrifying bacteria. A 1, 3 and 4 only B 1 and 3 only C 2, 3 and 4 only D 2 and 4 only

Accepted Answer

A

Question paper20 pages

Mark scheme2 pages

Questions as text

Q1 · A light microscope is used to observe two membranes that are 200 nm apart

Q2 · The electronmicrograph is of a chloroplast

Q3 · The diagram below is drawn from an electronmicrograph of an animal cell

Q4 · Which features enable an organism to be identified as a prokaryote?

Q5 · The diagram shows an electronmicrograph of a typical animal cell

Q6 · An animal cell and a plant cell are placed in distilled water

Q7 · The R groups (side chains) of amino acids can be hydrophobic, hydrophilic, acidic or basic

Q8 · Which describes the emulsion test for the presence of lipids?

Q9 · The structural formula of a carbohydrate molecule can be shown as: H C O H C OH HO C H H…

Q10 · The diagram shows part of a molecule of glycogen

Q11 · Which molecules contain a carboxyl group?

Q12 · The diameter of some atoms when they form bonds are given in the table

Q13 · Which feature of water is least likely to affect the life of an animal in a tropical rain…

Q14 · Two pairs of students each counted the number of bubbles of oxygen given off in a minute…

Q15 · When investigating the rate of reaction of the enzyme lipase on the hydrolysis of…

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

Q17 · The diagram shows a cell that produces protease enzymes

Q18 · The diagram shows two identical plant cells

Q19 · Chromosome telomeres are essential for DNA replication and are not completely replaced…

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

Q21 · Which features of mitosis ensure that the genetic constitution of the cell is maintained?

Q22 · What is the maximum number of hydrogen bonds in a length of DNA containing 700…

Q23 · Which type of molecule is the end product of translation?

Q24 · A polypeptide molecule contains the amino acid sequence: glycine – leucine – lysine…

Q25 · Which plant cells do not contain a nucleus?

Q26 · The diagram shows three xerophytic leaves of the same type in three different conditions…

Q27 · The diagram shows how sucrose is loaded into a sieve tube element

Q28 · Halophytes are plants that can survive in regions where they are regularly exposed to sea…

Q29 · A number of different tissues occur in the walls of major blood vessels

Q30 · The diagram shows the pressure changes in various structures of the right side of the…

Q31 · Which statement is true for the Bohr effect?

Q32 · Aortic stenosis is a heart valve disorder in which the aortic semi-lunar valve opening is…

Q33 · What can be observed about some of the tissues in a transverse section of a mammalian…

Q34 · There is a lot of epidemiological evidence linking smoking to disease and early death

Q35 · Which row shows the effects of chronic bronchitis?

Q36 · A country had fewer than 2.5 deaths per 100 000 people from TB in one year and the next…

Q37 · A graft of tissue, such as skin, from a different person is usually rejected by the body

Q38 · The diagram shows a simplified nitrogen cycle

Q39 · Which statements about energy flow in ecosystems are correct?

Q40 · In many freshwater ecosystems, the availability of inorganic nitrogen compounds is a…

What was in this paper

What you needed in this session

Other variants, same session

This paper, other years