Cambridge A Level Biology 9700 — 2014 Oct/Nov Paper 1 · Variant 3

Question 1

1 The eyepiece of a microscope is fitted with an eyepiece graticule and a stage micrometer scale is placed on the microscope. Which statements about the stage micrometer scale are correct? 1 It allows you to measure the actual length of cells. 2 It allows you to calibrate the eyepiece graticule. 3 It changes in size as the objective lens changes from ×10 to ×40. A 1, 2 and 3 B 2 and 3 only C 1 only D 2 only

Accepted Answer

B

Question 2

2 Density gradient centrifuges are used to separate cell structures by their relative density. Larger cell structures have greater density and sink further down the centrifuge tube. What is the correct order of the cell structures, starting from the top of the centrifuge tube? A chloroplasts → nuclei → mitochondria → ribosomes B nuclei → chloroplasts → mitochondria → ribosomes C ribosomes → chloroplasts → mitochondria → nuclei D ribosomes → mitochondria → chloroplasts → nuclei

Accepted Answer

D

Question 3

3 Red blood cells have a diameter of 7000 nm. Pancreatic cells have a diameter of diameter 35 µm. What is correct about the relative sizes of these cells? A The red blood cells are 5 times larger. B The red blood cells are 50 times larger. C The red blood cells are 5 times smaller. D The red blood cells are 50 times smaller.

Accepted Answer

C

Question 4

4 Which cell structure shown in the electronmicrograph is the site of protein modification and packaging? D A C B

Accepted Answer

D

Question 5

5 The diagram shows some similarities between typical prokaryotes, chloroplasts and mitochondria. 1 2 3 4 5 Which is correct? 1 2 3 4 5 A chloroplasts circular DNA and mitochondria circular DNA and prokaryotes 70S ribosomes 70S ribosomes B chloroplasts circular DNA and prokaryotes circular DNA and mitochondria 80S ribosomes 80S ribosomes C mitochondria linear DNA and chloroplasts linear DNA and prokaryotes 70S ribosomes 70S ribosomes D mitochondria linear DNA and prokaryotes linear DNA and chloroplasts 80S ribosomes 80S ribosomes

Accepted Answer

A

Question 6

6 Samples of a mixture of biological molecules were tested using Benedict’s reagent, biuret solution and ethanol. After testing, the solutions were blue with Benedict’s reagent, purple with biuret and cloudy with ethanol. Which molecules could the mixture contain? W X H CH2OH OH HO CH2 C C C O H H H O H N C C OH H OH OH HOOC CH2 CH2 C C H C C H O N H OH CH3 C C H O N H H Y Z H OH H O HOCH2 CH2OH H C C H C O C R H C O H H H H O C C C C OH H O H C O C R O HO C C CH2OH O H OH H C O C R H A W, X and Y B W, X and Z C W, Y and Z D X, Y and Z

Accepted Answer

C

Question 7

7 The diagram shows a section of a polysaccharide. C C C O C C C O O C C C C C C O C C C O C C C In which polysaccharide(s) could this section be found? 1 amylose 2 cellulose 3 glycogen A 1 only B 2 only C 1 and 3 D 2 and 3

Accepted Answer

B

Question 8

8 Chromatography is a technique used to separate molecules by their solubility. The diagram shows one apparatus used for this technique. absorbent paper a mixture containing one or solvent more types of molecules As the solvent rises up the paper, the molecules with the greatest solubility in the solvent travel a fixed distance up the paper. When the solvent reaches the top of the paper, the paper is removed, dried and sprayed with a dye. The different molecules appear as coloured spots. Chromatography was carried out on four different carbohydrates; sucrose, cellulose, the products of hydrolysis of sucrose and the products of hydrolysis of cellulose. Which diagram shows the presence of the products of sucrose digestion? A B C D

Accepted Answer

D

Question 9

9 In all lipid molecules, where are double bonds located? A between fatty acids and glycerol B within fatty acids and within glycerol C within fatty acids only D within glycerol only

Accepted Answer

C

Question 10

10 Which of the following terms can be used to describe the secondary structure of a protein? 1 dipeptide 2 specific order of amino acids 3 α-helix 4 fibrous structure 5 β-pleated sheet A 1, 3, 4 and 5 B 1, 2 and 4 C 2 and 4 only D 3 and 5 only

Accepted Answer

D

Question 11

11 Why is haemoglobin stated to have a quaternary structure? A It has four haem groups. B It has two or more polypeptide chains. C It is coiled into a precise shape. D It is held together by four types of bonds.

Accepted Answer

B

Question 12

12 A quantity of an enzyme was added to a quantity of its substrate. The graphs show the changes in concentration of the enzyme, the substrate, the enzyme-substrate complex and the product over time. Which graph shows the change in the concentration of the enzyme-substrate complex? A B concentration concentration time time C D concentration concentration time time

Accepted Answer

A

Question 13

13 Which is correct for a competitive inhibitor of an enzyme? A inhibitor binds to a site on the enzyme the substrate concentration has no other than the active site effect on the level of inhibition B inhibitor binds to the active site of the increasing the substrate concentration enzyme decreases the effect of the inhibitor C inhibitor binds to the active site of the the substrate concentration has no enzyme effect on the level of inhibition D inhibitor binds to the enzyme-substrate increasing the substrate concentration complex decreases the effect of the inhibitor

Accepted Answer

B

Question 14

14 Which two substances maintain the fluidity of the cell membranes? A cholesterol and glycolipid B glycolipid and glycoprotein C glycoprotein and phospholipid D phospholipid and cholesterol

Accepted Answer

D

Question 15

15 Membrane proteins are called ‘peripheral’ if they are temporarily attached to the membrane or ‘integral’ if they are permanently attached to the membrane. Integral proteins are described as ‘intrinsic’ if they extend across the whole bilayer and ‘extrinsic’ if they are found only in one side of the bilayer. How would you describe a channel protein? A integral extrinsic B integral intrinsic C peripheral extrinsic D peripheral intrinsic

Accepted Answer

B

Question 16

16 The diagram shows apparatus set up to investigate the effect of changing the concentration of glucose in the surrounding solution on the movement of molecules through a selectively permeable membrane (Visking tubing) in 15 minutes. Visking tubing surrounding solution 10% glucose different concentrations solution from 1% to 10% glucose solution As the concentration of glucose solution in the surrounding solution increases, which statements are correct? 1 Net diffusion of water increases. 2 Glucose molecules reach an equilibrium quicker. 3 There is less change in the volume of surrounding solution. 4 Net diffusion of glucose increases. A 1, 2, 3 and 4 B 1, 2 and 4 only C 1 and 3 only D 2 and 3 only

Accepted Answer

D

Question 17

17 Which is always true of cytokinesis? 1 Cell structures replicate. 2 Cell structures are divided between two cells. 3 Nuclear envelope reforms. A 1, 2 and 3 B 1 and 3 only C 2 only D 3 only

Accepted Answer

C

Question 18

18 The statements are about genes and proteins, involved in breast cancer.

e The protein coded by the BRAC7 gene inhibits the growth of breast cancer cells.

e The protein coded by the p53 gene suppresses tumours.

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

gene
BRAC1 p53
A x x
B x J
Cc J x
D J J

key
¥ =normal active gene

X = mutated gene

Accepted Answer

A

Question 19

19 Which structural feature of the DNA molecule varies? A the arrangement of the sugar-phosphate groups B the double helical arrangement C the number of hydrogen bonds between base pairs D the pairing of the purines with pyrimidines

Accepted Answer

C

Question 20

20 DNA is said to replicate in a semi-conservative way. Results of Meselson and Stahl’s experiments gave overwhelming support to this theory. They used E. coli which has a generation time of 50 minutes. Here are the stages occuring in their experiment but they are in the wrong order. 14N DNA contains the ‘light’ isotope of nitrogen. 15N DNA contains the ‘heavy’ isotope. P All bacteria contain 15N DNA. Q All bacteria contain hybrid DNA (15N DNA and 14N DNA). R Bacteria contain either all 14N DNA or hybrid DNA. S Bacteria grown in a 15N medium for many generations. T Bacteria transferred to a 14N medium and sampled every 50 minutes. Which sequence of letters shows the correct order of the stages in the experiment? A P → S → T → R → Q B P → T → S → Q → R C S → P → T → Q → R D S → T → P → R → Q

Accepted Answer

C

Question 21

21 Which molecules are involved in transcription and which molecules are involved in translation? transcription translation A DNA and mRNA mRNA and tRNA B DNA and tRNA mRNA and amino acids C mRNA and amino acids DNA and mRNA D tRNA and mRNA amino acids and DNA

Accepted Answer

A

Question 22

22 Which processes occur in the vascular tissue in leaves and in roots? in leaves in roots A sucrose enters phloem water passes from phloem and is polymerised to starch to xylem by osmosis B sucrose enters phloem sucrose is used or polymerised by active transport and the water and the water potential becomes potential becomes more negative less negative C water passes from phloem to active transport of water into the xylem by osmosis, making the phloem xylem makes the water potential water potential less negative more negative D water passes out of xylem and phloem active transport of ions into and is lost through transpiration the xylem makes the water potential less negative

Accepted Answer

B

Question 23

23 The diagram shows the water potential (Ψ) in some plant cells and in their environment. cell 1 cell 2 Ψ = Ψ = cell 3 – 5 kPa Ψ = – 7 kPa – 4 kPa environment Ψ = – 5 kPa Which statements are correct? 1 Water moves into and out of all three cells. 2 There is a net movement of water into cell 1. 3 There is no movement of water from the environment to cell 2. 4 Water moves out of cell 1 so it becomes plasmolysed. A 1 and 2 B 1 and 3 C 3 and 4 D 4 only

Accepted Answer

A

Question 24

24 A region of a plant containing the vascular tissue is treated with a metabolic poison.

How will this treatment affect the transport between roots and leaves via xylem and phloem?

xylem phloem
A v v
B v x
Cc x v
D x x

key
/ = transport continues

X = transport stops

Accepted Answer

B

Question 25

25 A group of students were asked to look at the photomicrograph of a cross-section of unfamiliar material and make observations. X They described X as 1 circular 2 a hollow tube 3 a spherical structure Which description(s) are correct? A 1, 2 and 3 B 1 and 2 only C 1 only D 3 only

Accepted Answer

C

Question 26

26 What is correct for tissue fluid?

protein concentration

phagocytes platelets compared to blood plasma
A V JV higher
B x x higher
Cc V x lower
D x JV lower

key
/¥ = present
X = absent

Accepted Answer

C

Question 27

27 The graph shows the dissociation curves for adult haemoglobin at two different (unidentified) concentrations of carbon dioxide. Which point represents the oxygen concentration in red blood cells as they leave a resting muscle? 100 75 A % saturation of haemoglobin 50 B with oxygen D 25 C 0 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 partial pressure of O2 / kPa

Accepted Answer

D

Question 28

28 The diagram shows the pressure changes in various structures of the left side of the heart during the cardiac cycle. Which letter shows when the ventricle is empty of blood? A B C D pressure key / kPa left ventricle aorta left atrium 0 0 0.2 0.4 0.6 0.8 time / s

Accepted Answer

C

Question 29

29 Which statement concerning events that occur in the heart is correct? A As the wave of excitation passes through the atrioventricular node there is a time delay before it passes down the Purkyne tissue to the ventricles. B Movement of blood into the ventricles following atrial contraction causes the ventricular blood pressure to rise above the blood pressure in the atria, closing the atrioventricular valve. C The band of non-conducting tissue between the atria and ventricles causes the wave of excitation to pass through the Purkyne tissue to reach the atrioventricular node. D The sinoatrial node in the left atrium, sends out a wave of excitation that spreads across the walls of the atria, resulting in the movement of blood from the atria into the ventricles.

Accepted Answer

A

Question 30

30 Which row correctly shows the areas of the gas exchange system that contain cartilage, ciliated epithelium, goblet cells and smooth muscle? cartilage ciliated epithelium goblet cells smooth muscle A bronchiole, trachea bronchiole, trachea bronchus, trachea bronchiole, trachea B bronchus, trachea bronchiole, bronchus bronchus, trachea bronchiole, trachea C bronchiole, trachea bronchus, trachea bronchiole, bronchus bronchiole, bronchus, trachea D bronchus, trachea bronchiole, bronchus, trachea bronchiole, bronchus, trachea bronchus, trachea

Accepted Answer

D

Question 31

31 Which observation would indicate a difference between the structure of the gas exchange system of a cigarette smoker and a non-smoker? A absence of ciliated epithelium B decrease in elastic fibres C enlargement of goblet cells D increase in smooth muscle

Accepted Answer

C

Question 32

32 Asthma is a lung disease triggered by the inhalation of an allergen such as pollen or dust. The allergen triggers; ● bronchi and bronchioles to become inflamed and narrow ● goblet cells lining these airways to secrete excess mucus. Which effects will these responses have on the gaseous exchange system of a person with asthma? 1 decrease the diffusion gradient for oxygen in the lungs 2 increase the diffusion distance from the alveoli into the blood 3 increase the risk of developing a lung infection A 1 and 2 B 1 and 3 C 2 and 3 D 3 only

Accepted Answer

B

Question 33

33 A person who returns home after a visit to a foreign country starts to have fevers at regular intervals. Blood tests taken between the fevers and during the fevers show a decrease in the number of red blood cells (anaemia). Which disease does this person have? A cholera B HIV / AIDS C malaria D TB

Accepted Answer

C

Question 34

34 Why do people in refugee camps have a high risk of being infected by cholera? A Drinking water is likely to be contaminated with sewage. B People live in close contact, increasing the risk of droplet infection. C There is a shortage of antibiotics. D There is a shortage of food and water.

Accepted Answer

A

Question 35

35 Which statements explain why cholera has not been eradicated by vaccination? 1 Cholera is caused by the bacterium Vibrio cholerae. 2 Many people can have the disease, but show no symptoms. 3 People are mobile due to global trade and tourism. 4 The cholera pathogens target cells in the small intestine. A 1, 2, 3 and 4 B 1 and 2 only C 2 and 4 only D 3 and 4 only

Accepted Answer

D

Question 36

36 Cells which divide and give rise to macrophages are called stem cells. Where in the body do these stem cells divide? A blood plasma B bone marrow C lymph nodes D tissue fluid

Accepted Answer

B

Question 37

37 Which type of immunity occurs following infection by a pathogen? natural artificial active A B passive C D

Accepted Answer

A

Question 38

38 The diagram shows part of the nitrogen cycle. Which process is carried out by denitrifying bacteria? nitrogen in the air A B D herbivore dead organic matter C bean plant with root nodules nitrates

Accepted Answer

D

Question 39

39 The graph shows the annual changes of the following factors in a lake. • intensity of light per day • numbers of producers • numbers of primary consumers • quantity of nutrients Which curve represents the numbers of primary consumers? A A increasing quantity B B C C D D winter summer winter time of year

Accepted Answer

D

Question 40

40 In a food chain, which link involves the least efficient energy transfer? A Corn traps sunlight during photosynthesis. B Mice eat the grain from corn. C Mongooses feed on snakes. D Snakes feed on mice.

Accepted Answer

A

Question paper20 pages

Mark scheme2 pages

Questions as text

Q1 · The eyepiece of a microscope is fitted with an eyepiece graticule and a stage micrometer…

Q2 · Density gradient centrifuges are used to separate cell structures by their relative…

Q3 · Red blood cells have a diameter of 7000 nm

Q4 · Which cell structure shown in the electronmicrograph is the site of protein modification…

Q5 · The diagram shows some similarities between typical prokaryotes, chloroplasts and…

Q6 · Samples of a mixture of biological molecules were tested using Benedict’s reagent, biuret…

Q7 · The diagram shows a section of a polysaccharide

Q8 · Chromatography is a technique used to separate molecules by their solubility

Q9 · In all lipid molecules, where are double bonds located?

Q10 · Which of the following terms can be used to describe the secondary structure of a protein?

Q11 · Why is haemoglobin stated to have a quaternary structure?

Q12 · A quantity of an enzyme was added to a quantity of its substrate

Q13 · Which is correct for a competitive inhibitor of an enzyme?

Q14 · Which two substances maintain the fluidity of the cell membranes?

Q15 · Membrane proteins are called ‘peripheral’ if they are temporarily attached to the…

Q16 · The diagram shows apparatus set up to investigate the effect of changing the…

Q17 · Which is always true of cytokinesis?

Q18 · The statements are about genes and proteins, involved in breast cancer

Q19 · Which structural feature of the DNA molecule varies?

Q20 · DNA is said to replicate in a semi-conservative way

Q21 · Which molecules are involved in transcription and which molecules are involved in…

Q22 · Which processes occur in the vascular tissue in leaves and in roots?

Q23 · The diagram shows the water potential (Ψ) in some plant cells and in their environment

Q24 · A region of a plant containing the vascular tissue is treated with a metabolic poison

Q25 · A group of students were asked to look at the photomicrograph of a cross-section of…

Q26 · What is correct for tissue fluid?

Q27 · The graph shows the dissociation curves for adult haemoglobin at two different…

Q28 · The diagram shows the pressure changes in various structures of the left side of the…

Q29 · Which statement concerning events that occur in the heart is correct?

Q30 · Which row correctly shows the areas of the gas exchange system that contain cartilage…

Q31 · Which observation would indicate a difference between the structure of the gas exchange…

Q32 · Asthma is a lung disease triggered by the inhalation of an allergen such as pollen or dust

Q33 · A person who returns home after a visit to a foreign country starts to have fevers at…

Q34 · Why do people in refugee camps have a high risk of being infected by cholera?

Q35 · Which statements explain why cholera has not been eradicated by vaccination?

Q36 · Cells which divide and give rise to macrophages are called stem cells

Q37 · Which type of immunity occurs following infection by a pathogen?

Q38 · The diagram shows part of the nitrogen cycle

Q39 · The graph shows the annual changes of the following factors in a lake

Q40 · In a food chain, which link involves the least efficient energy transfer?

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