Cambridge A Level Biology 9700 — 2013 Oct/Nov Paper 1 · Variant 3

Question 1

1 For which process is the large surface area of the cristae in the mitochondria important? A energy radiation B enzyme reaction C gaseous exchange D protein synthesis

Accepted Answer

B

Question 2

2 What is not a limitation of an electron microscope? A Electrons do not travel far in air so the whole system must be in a vacuum. B The electron beam cannot penetrate far into biological material. C The typical specimen viewed in a vacuum must be dehydrated. D There is an increase in resolution and magnification compared with the light microscope.

Accepted Answer

D

Question 3

3 What explains why cells with no nucleoli die? A They do not have centrioles and cannot divide. B They do not have mitochondria and cannot release energy. C They do not have mRNA and cannot transcribe DNA. D They do not have ribosomes and cannot synthesise protein.

Accepted Answer

D

Question 4

4 Which statements about a typical prokaryotic cell are correct? 1 It is smaller than 2 µm. 2 It has a nucleus. 3 Its has circular DNA. 4 It has small (70S) ribosomes. A 1 and 2 only B 1 and 3 only C 1, 3 and 4 only D 2, 3 and 4 only

Accepted Answer

C

Question 5

5 When mitochondria are extracted from cells for biochemical study, they are usually kept in a 0.25 mol dm–3 sucrose solution. Why is the sucrose solution used? A to act as a solvent B to enable the rate of reaction of the mitochondria to be determined C to prevent the mitochondria from changing in structure D to provide a source of energy

Accepted Answer

C

Question 6

6 Which shows the basic unit of cellulose? A B CH2OH CH2OH H C O OH H C O H H H C C C C OH H OH H HO C C H HO C C OH H OH H OH C D OH H H C O OH HO C O H H OH C C C C H H H H HO C C H H C C OH CH2OH OH CH2OH OH

Accepted Answer

A

Question 7

7 Which explains why haemoglobin is suitable as an oxygen carrier? 1 The haem group combines with oxygen. 2 The iron combines with oxygen reversibly. 3 Haemoglobin changes shape as oxygen loads. A 1 only B 1 and 2 only C 2 and 3 only D 1, 2 and 3

Accepted Answer

D

Question 8

8 Which diagram shows part of a structural polysaccharide? O O O O A O O O O O O O O O B O O O O O O O C O O O O O O O O O O O D O O O O O

Accepted Answer

B

Question 9

9 The diagrams show the structures of two amino acids, each of which has more than one amine (–NH2) group. 1 3 4 H2N CH COOH H2N CH COOH CH2 CH2 CH2 C 5 O NH2 CH2 NH 2 C HN NH2 A peptide bond is formed between the two amino acids. Which groups form the peptide bond? A 1 and 3 B 1 and 5 C 2 and 4 D 2 and 5

Accepted Answer

A

Question 10

10 Which combination of bond types correctly shows the weak and strong bonds that hold a molecule of protein in shape? types of bond hydrogen disulfide ionic A strong strong weak B strong weak strong C weak strong strong D weak strong weak

Accepted Answer

D

Question 11

11 Which is correct for competitive inhibitors of enzymes? 1 They occupy the active site of an enzyme. 2 They have exactly the same shape as the substrate. 3 They can be used to control the rate of enzyme activity. 4 They can bind to a site on an enzyme other than the active site. A 1 only B 1 and 3 only C 1, 2 and 3 only D 2, 3 and 4 only

Accepted Answer

B

Question 12

12 The graph shows the course of an enzyme-catalysed reaction at 30 °C. concentration of product X time What is true at time X? A Most enzyme molecules will have free active sites. B The number of available substrate molecules is high. C The number of enzyme-substrate complexes is low. D The rate remains the same if more enzyme is added.

Accepted Answer

B

Question 13

13 Which statement concerning the role of cholesterol in the cell surface membrane is correct? A It can act as a barrier to the entry into the cell of non-polar molecules. B It helps the entry and exit of ions through the fatty acids. C It maintains the fluidity of the membrane at low temperatures. D It makes the membrane more permeable to very small water-soluble substances.

Accepted Answer

C

Question 14

14 Which processes that contribute to transport across cell surface membranes are active or

passive?
endocytosis | exocytosis facilitated osmosis
diffusion
A v v x x key
B v x v x ¥ =active
Cc Xx v Xx v X = passive
D x x v v

Accepted Answer

A

Question 15

15 In an investigation, four sucrose solutions were separated from each other by partially permeable membranes. solution 1 1.1 mol dm–3 solution 2 0.8 mol dm–3 solution 3 0.5 mol dm–3 solution 4 0.1 mol dm–3 Which shows the direction in which water will move between the solutions? A from 1 and 2 to 3 and 4 B from 2, 3 and 4 to 1 C from 1 to 3 to 2 and 4 D from 1, 2 and 3 to 4

Accepted Answer

B

Question 16

16 The diagram shows a partially plasmolysed plant cell. solution X Z solution Y What is found at Z? A air B solution X C solution Y D water

Accepted Answer

C

Question 17

17 The diagram shows part of the life cycle of the honey bee, Apis mellifera. 2 unfertilised male drones 1 (n = 16) queen gametes (2n = 32) (n = 16) 3 fertilised female workers (2n = 32) Where does mitosis occur? A 1 only B 1 and 2 only C 1 and 3 only D 2 and 3 only

Accepted Answer

D

Question 18

18 The graph shows the change in the quantity of DNA in a cell during a reduction division (meiosis). 4 quantity of DNA / arbitrary units 2 0 time A cell with one pair of chromosomes (2n = 2) undergoes meiosis. Which nucleus is formed as a result of this division? A B C D

Accepted Answer

D

Question 19

19 What is the minimum number of hydrogen bonds in a length of DNA containing 700 base pairs? A 350 B 700 C 1400 D 2100

Accepted Answer

C

Question 20

20 Which term best describes the length of DNA that codes for the synthesis of a polypeptide? A anticodon B codon C gene D nucleotide

Accepted Answer

C

Question 21

21 Which statements about complementary base pairing are correct? 1 It occurs during translation. 2 Purines and pyrimidines are the same size. 3 The base pairs are of equal length. 4 Uracil forms three hydrogen bonds with adenine. A 1 and 2 only B 1 and 3 only C 2 and 3 only D 3 and 4 only

Accepted Answer

B

Question 22

22 What is transpiration and which advantage does it give to a plant? transpiration advantage to a plant A evaporation of water maintains the from leaf surfaces water potential B evaporation of water stomata are open from leaf surfaces for gas exchange C loss of water vapour maintains the from leaves water potential D loss of water vapour stomata are open from leaves for gas exchange

Accepted Answer

D

Question 23

23 Which feature of xylem vessel elements allows them to stay open as transpiration increases? A new vessel elements carry extra water as a plant grows B there are no cross walls between vessel elements C vessel elements form narrow tubes D walls of vessel elements contain lignin

Accepted Answer

D

Question 24

24 What occurs in the sieve tube elements of a photosynthesising leaf and an actively growing root? sieve tube elements in leaf sieve tube elements in root A water potential decreases sugars are moved in B water potential decreases sugars are moved out C water potential increases sugars are moved in D water potential increases sugars are moved out

Accepted Answer

B

Question 25

25 What occurs in the apoplast and symplast pathways? water enters water moves from water enters cytoplasm through cell to cell through vacuoles cell surface membrane intercellular spaces A apoplast apoplast symplast B apoplast symplast symplast C symplast apoplast apoplast D symplast symplast apoplast

Accepted Answer

D

Question 26

26 Some fungi cause wilting in crop plants by growing within the xylem vessels. Which process will be directly affected by these fungi? A cohesion between water molecules B development of root pressure C mass flow during translocation D uptake of water by root hair cells

Accepted Answer

A

Question 27

27 Which statement correctly identifies a similarity between blood plasma and tissue fluid? A Protein is found in equal concentration in both blood plasma and tissue fluid. B The blood plasma is under the same pressure as the tissue fluid. C The water potential of the blood plasma and tissue fluid are equal. D White blood cells are found in both blood plasma and tissue fluid.

Accepted Answer

D

Question 28

28 Which reactions are not likely to occur in blood that is passing through active tissues? 1 Hb  +  4O2  →  HbO8 2 HbO8  +  H+  →  HHb  +  4O2 3 HCO3 –  +  H+  →  H2CO3 4 H2O  +  CO2  →  H2CO3 A 1 and 2 only B 1 and 3 only C 2 and 3 only D 2, 3 and 4 only

Accepted Answer

B

Question 29

29 The pressure of blood entering capillaries is about seven times higher than that of blood leaving the capillaries. What correctly explains this observation? 1 Blood pressure decreases with distance from the heart. 2 Tissue fluid formation is due to a net loss of plasma from capillaries. 3 Veins have fewer elastic and muscle fibres in their walls than arteries. A 1, 2 and 3 B 1 and 2 only C 1 and 3 only D 2 and 3 only

Accepted Answer

B

Question 30

30 The red blood cell count of humans increases when they remain at high altitudes. Why does this occur? 1 to increase the Bohr effect 2 to increase the diffusion gradient for oxygen in the lungs 3 to maintain transport of oxygen A 3 only B 1 and 2 only C 2 and 3 only D 1, 2 and 3

Accepted Answer

A

Question 31

31 Goblet cells are found in the trachea.

Which organelles would be found in large numbers in a goblet cell?

Golgi

mitochondria ribosomes
apparatus

J key
¥ = present in large numbers

X = not present in large numbers

00NO WwW >
Kk 4 4
QS 4 O&M

v
v
x

Accepted Answer

A

Question 32

32 The photomicrographs show a TS of an artery from a non-smoker and a TS of an artery from a smoker. non-smoker smoker What is the reason for the appearance of smoker’s artery? A A cancerous tumour has formed and is blocking the lumen. B Nicotine has damaged the artery endothelium causing a plaque. C Tar has stuck to the artery wall forming a blockage. D The artery has become constricted due to carbon monoxide.

Accepted Answer

B

Question 33

33 Which row describes emphysema? total surface area lung tissue of the alveoli A less elastic decreased B less elastic increased C more elastic decreased D more elastic increased

Accepted Answer

A

Question 34

34 Which row is correct? causative method method disease agent of transmission of control A AIDS HIV intimate contact antibiotics B cholera virus waterborne oral rehydration therapy (ORT) C malaria bacterium insect vector antimalarial drugs D tuberculosis (TB) bacterium airborne vaccination

Accepted Answer

D

Question 35

35 Scientists are concerned that avian (bird) flu caused by the H5N1 virus could infect humans and cause a pandemic. What could help prevent humans from spreading the disease? 1 killing all poultry 2 reducing the number of air flights 3 taking a course of antibiotics A 1 only B 2 only C 3 only D 1, 2 and 3

Accepted Answer

B

Question 36

36 What are the function(s) of plasma cells during an immune response? 1 destroy cancer cells 2 differentiate into memory cells 3 secrete antibodies A 2 only B 3 only C 2 and 3 only D 1, 2 and 3

Accepted Answer

B

Question 37

37 Some of the facts about a pathogen, P, are that: 1 it is transmitted in food and water 2 it lives in human intestines 3 it has many genes coding for surface proteins 4 it changes its surface antigens 5 it may or may not trigger an immune response. Which explains why it is difficult to develop an effective vaccine for P? A P can mutate to produce different antigens. B P is a eukaryotic cell with many genes. C P is found in contaminated food and water and affects the gut. D People can be infected with P and may not show symptoms.

Accepted Answer

A

Question 38

38 Which description is correct for B-lymphocytes?

0 0O DW >

processed in
the thymus

x KOK

release
antibodies
immediately
after formation

x < x

act in the cell
mediated
response

x x KOK

can act as
antigen
presenting cells

<< x x

key
Y =correct

X =incorrect

Accepted Answer

D

Question 39

39 In a mangrove ecosystem, leaves from the grey mangrove plants fall into the water and sink to the mud below. They are then broken down by bacteria and fungi. Invertebrates such as crabs, prawns, and molluscs live in the mud and feed on the dead leaves. The bullseye fish feeds on the invertebrates. Humans eat prawns, crabs and fish. Herons and other wading birds live and breed in the mangroves. These birds feed on invertebrates and fish. What is correct about this ecosystem? A Bacteria, fungi, crabs, prawns and molluscs form the community in the mud. B Bullseye fish are at the second trophic level in the food web. C Fungi in the water are the main producers in the ecosystem. D Grey mangroves are the ecological niche of herons.

Accepted Answer

A

Question 40

40 Two species of birds feed on different insects living on the same tree and so do not compete for food. Which statement describes these two species of birds? A They occupy different habitats in the same ecosystem. B They occupy the same habitat in the same ecosystem. C They occupy different niches in the same habitat. D They occupy the same niche in the same habitat.

Accepted Answer

C

Question paper16 pages

Mark scheme2 pages

Questions as text

Q1 · For which process is the large surface area of the cristae in the mitochondria important?

Q2 · What is not a limitation of an electron microscope?

Q3 · What explains why cells with no nucleoli die?

Q4 · Which statements about a typical prokaryotic cell are correct?

Q5 · When mitochondria are extracted from cells for biochemical study, they are usually kept…

Q6 · Which shows the basic unit of cellulose?

Q7 · Which explains why haemoglobin is suitable as an oxygen carrier?

Q8 · Which diagram shows part of a structural polysaccharide?

Q9 · The diagrams show the structures of two amino acids, each of which has more than one…

Q10 · Which combination of bond types correctly shows the weak and strong bonds that hold a…

Q11 · Which is correct for competitive inhibitors of enzymes?

Q12 · The graph shows the course of an enzyme-catalysed reaction at 30 °C

Q13 · Which statement concerning the role of cholesterol in the cell surface membrane is…

Q14 · Which processes that contribute to transport across cell surface membranes are active or…

Q15 · In an investigation, four sucrose solutions were separated from each other by partially…

Q16 · The diagram shows a partially plasmolysed plant cell

Q17 · The diagram shows part of the life cycle of the honey bee, Apis mellifera

Q18 · The graph shows the change in the quantity of DNA in a cell during a reduction division…

Q19 · What is the minimum number of hydrogen bonds in a length of DNA containing 700 base pairs?

Q20 · Which term best describes the length of DNA that codes for the synthesis of a polypeptide?

Q21 · Which statements about complementary base pairing are correct?

Q22 · What is transpiration and which advantage does it give to a plant?

Q23 · Which feature of xylem vessel elements allows them to stay open as transpiration…

Q24 · What occurs in the sieve tube elements of a photosynthesising leaf and an actively…

Q25 · What occurs in the apoplast and symplast pathways?

Q26 · Some fungi cause wilting in crop plants by growing within the xylem vessels

Q27 · Which statement correctly identifies a similarity between blood plasma and tissue fluid?

Q28 · Which reactions are not likely to occur in blood that is passing through active tissues?

Q29 · The pressure of blood entering capillaries is about seven times higher than that of blood…

Q30 · The red blood cell count of humans increases when they remain at high altitudes

Q31 · Goblet cells are found in the trachea

Q32 · The photomicrographs show a TS of an artery from a non-smoker and a TS of an artery from…

Q33 · Which row describes emphysema?

Q34 · Which row is correct?

Q35 · Scientists are concerned that avian (bird) flu caused by the H5N1 virus could infect…

Q36 · What are the function(s) of plasma cells during an immune response?

Q37 · Some of the facts about a pathogen, P, are that: 1 it is transmitted in food and water 2…

Q38 · Which description is correct for B-lymphocytes?

Q39 · In a mangrove ecosystem, leaves from the grey mangrove plants fall into the water and…

Q40 · Two species of birds feed on different insects living on the same tree and so do not…

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