Cambridge A Level Biology 9700 — 2015 Oct/Nov Paper 1 · Variant 3

Question 1

1 Which size of ribosome is found in chloroplasts? A 60S B 70S C 80S D 90S

Accepted Answer

B

Question 2

2 Different units are used when measuring biological specimens. In which rows are the same measurements correctly expressed in each of the units shown in the column headings? mm µm nm 1 1.0 1.0 × 103 1.0 × 106 2 2.5 2.5 × 103 2.5 × 106 3 5.0 5.0 × 104 5.0 × 107 4 25.0 2.5 × 104 2.5 × 107 A 1, 2, 3 and 4 B 1, 2 and 4 only C 1 and 2 only D 3 and 4 only

Accepted Answer

B

Question 3

3 Which features of cilia and root hairs are correct? cannot be more than one increase cell resolved with contain present on a surface area the light vacuoles cell microscope A cilia cilia root hairs root hairs B cilia root hairs cilia cilia C root hairs cilia root hairs cilia D root hairs root hairs cilia root hairs

Accepted Answer

C

Question 4

4 The diagram shows a typical animal cell. Each labelled structure is involved with the synthesis of biological molecules. 1 2 3 4 Within which structures are glycoproteins, proteins and steroids synthesised? glycoproteins proteins steroids A 2 3 1 B 2 3 4 C 4 2 3 D 4 1 2

Accepted Answer

B

Question 5

5 What is present in a Vibrio cholerae cell? cell Golgi wall body A B C D rough endoplasmic reticulum

Accepted Answer

A

Question 6

6 What is correct for a typical prokaryotic cell? cell wall cell diameter ribosomes A cellulose 1-5 µm 70S B cellulose 5-40 µm 70S and 80S C peptidoglycan 1-5 µm 70S D peptidoglycan 5-40 µm 70S and 80S

Accepted Answer

C

Question 7

7 The table shows the results of tests carried out on a sample of biological molecules.

test colour observed
Benedict’s blue
biuret purple
iodine blue-black

Which shows the types of molecules present in the sample?

protein sugar starch
A v x x
B x v x
Cc v x v
D x v v

key
J present

X absent

Accepted Answer

C

Question 8

8 The synthesis of biological molecules requires the formation of bonds. Which row is correct? a bond forms between a  β-1,4 bond forms the hydroxyl group of the carboxylic the phosphate of one between the monomers acid group is removed and a monomer and the sugar to give an unbranched carbon-nitrogen bond is formed to of the next monomer chain give an unbranched chain A polynucleotide amylose polypeptide B polynucleotide cellulose polypeptide C phospholipid amylose polynucleotide D phospholipid cellulose polynucleotide

Accepted Answer

B

Question 9

9 Which row describes a triglyceride?

hydrophobic insoue in
A v v key
B v x ¥ correct
Cc x v X not correct
D x x

Accepted Answer

B

Question 10

10 High concentrations of urea break all bonds, except covalent bonds, in protein molecules. Which level of protein structure would remain unchanged when a protein is treated with urea? A primary B secondary C tertiary D quaternary

Accepted Answer

A

Question 11

11 Haemoglobin, a globular protein, consists of four polypeptide chains, two alpha chains and two beta chains. In normal individuals, in the DNA which codes for each beta chain, the sixth triplet has a code for glutamic acid. In individuals with sickle cell anaemia this base triplet mutates and codes for valine. What does this mutation change in the haemoglobin molecule? A the iron content B the primary structure C the quaternary structure D the secondary structure

Accepted Answer

B

Question 12

12 The graph shows the concentration of one of the substances which is involved in an enzyme-catalysed reaction. concentration X time Which substance is shown by line X? A enzyme B enzyme-product complex C enzyme-substrate complex D substrate

Accepted Answer

A

Question 13

13 What describes the induced fit mode of action of an enzyme? A The binding of the active site to the substrate causes the enzyme to change shape. B The substrate and active site have complementary shapes that form temporary bonds. C The substrate causes a change in enzyme shape so the active site can bind. D The substrate changes shape so it can bind to the active site.

Accepted Answer

C

Question 14

14 Line X represents the course of an enzyme-catalysed reaction under optimum conditions. Line Y shows the action of the same enzyme on the same substrate but with one variable changed: substrate concentration or pH or temperature. 100 percentage Y of unreacted 50 substrate molecules X 0 time Which changes to the variables could give the results shown by line Y? 1 decreased substrate concentration 2 higher pH 3 lower temperature A 1, 2 and 3 B 1 and 2 only C 1 and 3 only D 2 and 3 only

Accepted Answer

D

Question 15

15 Which descriptions are correct about transport across cell surface membranes? active processes passive processes A active transport exocytosis and osmosis B active transport and exocytosis endocytosis and diffusion C endocytosis and exocytosis diffusion and osmosis D exocytosis and active transport osmosis and endocytosis

Accepted Answer

C

Question 16

16 Which statements about the fluid mosaic model of a membrane are correct? 1 Saturated fatty acid tails inhibit the movement of phospholipids in the membrane. 2 Glycoproteins in the outer layer of the membrane can move. 3 Channel proteins are fixed in position. A 1, 2 and 3 B 1 and 2 only C 1 and 3 only D 2 and 3 only

Accepted Answer

B

Question 17

17 The diagram shows apparatus set up to investigate diffusion. selectively 20% glucose permeable solution membrane Y 10% glucose solution in V What shows net diffusion of glucose and water molecules? A glucose and water into V B glucose and water into Y C glucose into V and water into Y D glucose into Y and water into V

Accepted Answer

C

Question 18

18 The photomicrograph shows a cell undergoing mitosis. What is happening in this cell? A Centrioles are replicating. B Chromatin is condensing. C DNA is replicating. D Spindle microtubules are shortening.

Accepted Answer

D

Question 19

19 Which row shows the products of mitosis, reduction division (meiosis) and fertilisation? products products of product of of mitosis meiosis fertilisation A four diploid cells two diploid cells diploid cell B four haploid cells four diploid cells haploid cell C two diploid cells four haploid cells diploid cell D two diploid cells two haploid cells haploid cell

Accepted Answer

C

Question 20

20 Which statements describe how a gene mutation can lead to the production of a non-functional protein? 1 During transcription an incorrect nucleotide is added to a DNA molecule. 2 A codon in the mRNA transcribed from the mutated gene is changed. 3 The order of the bases in an anticodon on tRNA is altered during translation. A 1, 2 and 3 B 1 and 2 only C 2 and 3 only D 2 only

Accepted Answer

D

Question 21

21 Some antibiotics kill prokaryotes by binding to RNA polymerase. What effect will this have on protein synthesis? A Codons on mRNA will be unable to hydrogen bond to complementary anticodons on tRNA. B Condensation reactions joining RNA nucleotides will not take place to form mRNA. C DNA will not unwind and unzip to allow for base-pairing with RNA nucleotides. D Free RNA nucleotides will not base-pair to exposed bases on the DNA template strand.

Accepted Answer

B

Question 22

22 Which row correctly describes cytosine? number of hydrogen bonds ring structure it forms with its type of base complementary base A double three purine B double two pyrimidine C single three pyrimidine D single two purine

Accepted Answer

C

Question 23

23 The photomicrograph shows a transverse section of a leaf. Which cell has the least negative water potential? C B D A

Accepted Answer

A

Question 24

24 The diagram shows the results of an experiment on transpiration using two different leaves. Each leaf was left on a balance in daylight in a closed room and their mass recorded at 1 hour intervals. mass of leaf leaf 1 leaf 2 0 1 2 3 4 5 time / hours Which conclusions could be correct? 1 The loss in mass is mainly due to evaporation of water. 2 The stomata in both leaves close after 1 hour. 3 Leaf 1 has a larger surface area than leaf 2. A 1, 2 and 3 B 1 and 2 only C 1 and 3 only D 2 and 3 only

Accepted Answer

B

Question 25

25 Which processes are involved in the transport of sucrose in plants? 1 active transport 2 mass flow 3 osmosis A 1, 2 and 3 B 1 and 2 only C 1 and 3 only D 2 and 3 only

Accepted Answer

A

Question 26

26 Which changes to the water potential and the volume of liquid in the phloem occur when carbohydrate is moved from phloem sieve tubes into a sink? water potential in volume of liquid phloem sieve in phloem tubes becomes sieve tubes A less negative decreased B less negative increased C more negative decreased D more negative increased

Accepted Answer

A

Question 27

27 Which reactions take place in a capillary in an active tissue? 1 the formation of carbonic acid from carbon dioxide and water 2 the formation of carbaminohaemoglobin from carbon dioxide and haemoglobin 3 the formation of haemoglobinic acid from haemoglobin and hydrogen ions 4 the formation of carbon dioxide and water from hydrogen carbonate ions and hydrogen ions A 1, 2, 3 and 4 B 1, 2 and 3 only C 2 and 4 only D 3 and 4 only

Accepted Answer

B

Question 28

28 What is present in the blood in human veins? 1 collagen 2 carbonic anhydrase 3 oxyhaemoglobin A 1, 2 and 3 B 1 and 2 only C 1 and 3 only D 2 and 3 only

Accepted Answer

D

Question 29

29 The diagram shows the electrical activity in cardiac muscle during one heart beat. R electrical activity T P O Q S time What is happening at each of the labelled stages in the cardiac cycle? O P QRS T A atria contract atrio-ventricular atria relax ventricles contract valve opens B impulse leaves AVN ventricles contract atria relax atrio-ventricular valve closes C impulse leaves SAN atria contract ventricles contract ventricles relax D ventricles relax atria contract atrio-ventricular ventricles relax valve closes

Accepted Answer

C

Question 30

30 Which statement about the pulmonary artery is correct? A it contains a series of valves B it contains blood at high pressure C it contains blood moving towards the heart D it contains oxygenated blood

Accepted Answer

B

Question 31

31 Red blood cells may contain a molecule known as 2,3-bisphophoglycerate (2,3BPG). When 2,3BPG binds to haemoglobin a higher partial pressure of oxygen is needed to bring about 50% saturation of haemoglobin with oxygen. Which statement about the effect of 2,3BPG is correct? A 2,3BPG in red blood cells causes the oxygen dissociation curve to shift to the left. B Binding of 2,3BPG to haemoglobin reduces the Bohr effect. C The binding of 2,3BPG to haemoglobin lowers the affinity of the haemoglobin for oxygen. D When 2,3BPG is absent, oxyhaemoglobin is less likely to unload oxygen.

Accepted Answer

C

Question 32

32 What is a correct location of cartilage and smooth muscle in the human gas exchange system? cartilage smooth muscle A bronchioles bronchioles B bronchioles trachea C trachea alveoli D trachea bronchi

Accepted Answer

D

Question 33

33 Which factors maintain the diffusion gradient for carbon dioxide at the surface of the alveoli? 1 blood flow past the alveoli 2 breathing movement exchanging air in the lungs 3 thin epithelial lining of the alveoli A 1 and 2 B 1 and 3 C 2 and 3 D 1 only

Accepted Answer

A

Question 34

34 The surface tension of the layer of liquid lining the alveoli tends to pull the walls inwards so alveoli could collapse. Which statements could explain how this is prevented? 1 alveolar fluid is moved around by cilia 2 elastic fibres keep the alveoli open 3 epithelial cells secrete a chemical that reduces the cohesion in water A 1 and 2 B 1 and 3 C 2 and 3 D 3 only

Accepted Answer

D

Question 35

35 The data shows how the number of human deaths caused by the bacterium Staphylococcus aureus has changed over a period of five years. Methicillin is an antibiotic used to treat a disease caused by S. aureus. MRSA is methicillin-resistant S. aureus. total number of deaths total number of deaths year caused by S. aureus caused by MRSA 1 369 355 2 452 431 3 456 681 4 420 890 5 428 1512 Which statement is not supported by this data? A More people have MRSA so the disease spreads. B MRSA is more likely to lead to death than S. aureus. C Resistant strains of MRSA are becoming more common. D S. aureus will always cause humans to die.

Accepted Answer

D

Question 36

36 What describes natural active immunity? A protection against a pathogen by an injection of antibodies B protection against a pathogen by drinking colostrum containing antibodies C stimulation of lymphocytes by antigens contained in a vaccine D stimulation of lymphocytes by antigens on the surface of invading pathogens

Accepted Answer

D

Question 37

37 The bacterium that causes the disease tetanus produces a toxin that acts as an antigen. The graph shows the concentration of an antibody in the blood of two people, G and H. On day 0, G was injected with antibodies to the tetanus toxin and H was injected with the vaccine for tetanus. 25 G H 20 antibody 15 concentration / arbitrary units 10 5 0 0 5 10 15 20 time / days time of injection time of infection with tetanus bacteria What would be the result after G and H were infected with the tetanus bacteria on day 20? A concentration of antibodies in H would remain constant B G would fail to produce tetanus antibodies C G would peak in antibody production 12 days after infection D H would produce a new antibody peak 12 days after infection

Accepted Answer

C

Question 38

38 What name is given to all the organisms of the same species living in an area? A community B ecosystem C niche D population

Accepted Answer

D

Question 39

39 The table shows the results of a field study of four species in a food chain in an area of woodland. number of biomass of one individual energy value per unit species individuals / arbitrary units mass / arbitrary units R 10 000 0.1 1.0 S 5 10.0 2.0 T 500 0.002 1.8 U 3 300 000.0 0.5 What is the energy flow in the food chain? from                          to A R T S U B S T R U C U R S T D U S T R

Accepted Answer

C

Question 40

40 The diagram shows a simplified nitrogen cycle. Which arrow represents the activity of nitrogen-fixing bacteria? nitrogen in atmosphere A plant animal proteins proteins D death and decay B ammonium compounds nitrites C nitrates

Accepted Answer

A

Question paper16 pages

Mark scheme2 pages

Questions as text

Q1 · Which size of ribosome is found in chloroplasts?

Q2 · Different units are used when measuring biological specimens

Q3 · Which features of cilia and root hairs are correct?

Q4 · The diagram shows a typical animal cell

Q5 · What is present in a Vibrio cholerae cell?

Q6 · What is correct for a typical prokaryotic cell?

Q7 · The table shows the results of tests carried out on a sample of biological molecules

Q8 · The synthesis of biological molecules requires the formation of bonds

Q9 · Which row describes a triglyceride?

Q10 · High concentrations of urea break all bonds, except covalent bonds, in protein molecules

Q11 · Haemoglobin, a globular protein, consists of four polypeptide chains, two alpha chains…

Q12 · The graph shows the concentration of one of the substances which is involved in an…

Q13 · What describes the induced fit mode of action of an enzyme?

Q14 · Line X represents the course of an enzyme-catalysed reaction under optimum conditions

Q15 · Which descriptions are correct about transport across cell surface membranes?

Q16 · Which statements about the fluid mosaic model of a membrane are correct?

Q17 · The diagram shows apparatus set up to investigate diffusion

Q18 · The photomicrograph shows a cell undergoing mitosis

Q19 · Which row shows the products of mitosis, reduction division (meiosis) and fertilisation?

Q20 · Which statements describe how a gene mutation can lead to the production of a…

Q21 · Some antibiotics kill prokaryotes by binding to RNA polymerase

Q22 · Which row correctly describes cytosine?

Q23 · The photomicrograph shows a transverse section of a leaf

Q24 · The diagram shows the results of an experiment on transpiration using two different leaves

Q25 · Which processes are involved in the transport of sucrose in plants?

Q26 · Which changes to the water potential and the volume of liquid in the phloem occur when…

Q27 · Which reactions take place in a capillary in an active tissue?

Q28 · What is present in the blood in human veins?

Q29 · The diagram shows the electrical activity in cardiac muscle during one heart beat

Q30 · Which statement about the pulmonary artery is correct?

Q31 · Red blood cells may contain a molecule known as 2,3-bisphophoglycerate (2,3BPG)

Q32 · What is a correct location of cartilage and smooth muscle in the human gas exchange…

Q33 · Which factors maintain the diffusion gradient for carbon dioxide at the surface of the…

Q34 · The surface tension of the layer of liquid lining the alveoli tends to pull the walls…

Q35 · The data shows how the number of human deaths caused by the bacterium Staphylococcus…

Q36 · What describes natural active immunity?

Q37 · The bacterium that causes the disease tetanus produces a toxin that acts as an antigen

Q38 · What name is given to all the organisms of the same species living in an area?

Q39 · The table shows the results of a field study of four species in a food chain in an area…

Q40 · The diagram shows a simplified nitrogen cycle

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