Cambridge A Level Biology 9700 — 2010 Oct/Nov Paper 1 · Variant 2

Question 1

1 Which steps are needed to find the actual width of a xylem vessel viewed in transverse section using a ×40 objective lens? 1 Convert from mm to µm by multiplying by 10–3. 2 Calibrate the eyepiece graticule using a stage micrometer on ×10 objective lens. 3 Measure the width of the xylem vessel using an eyepiece graticule. 4 Multiply the number of eyepiece graticule units by the calibration of the eyepiece graticule. A 1, 2, 3 and 4 B 2, 3 and 4 only C 1 and 2 only D 3 and 4 only

Accepted Answer

D

Question 2

2 A specimen is viewed under a microscope using green light with a wavelength of 510 nm. If the same specimen is viewed under the same conditions, but using red light with a wavelength of 650 nm instead, what effect will this have on the magnification and on the resolution of the microscope? magnification resolution A decreased decreased B increased increased C remains the same decreased D remains the same increased

Accepted Answer

C

Question 3

3 Which cell organelle does not contain nucleic acid? A chloroplast B Golgi apparatus C lysosome D ribosome

Accepted Answer

B

Question 4

4 The diameter of living cells varies considerably. The typical diameters are a eukaryote, such as a white blood cell 1.5 × 101 µm a prokaryote, such as Streptococcus 7.5 × 102 nm Use these measurements to find the maximum number of each cell type which could fit along a line 1 cm long. number of white number of blood cells Streptococcus cells A 6.7 × 103 1.3 × 105 B 6.7 × 102 1.3 × 104 C 6.7 × 101 1.3 × 103 D 6.7 × 100 1.3 × 102

Accepted Answer

B

Question 5

5 Cells consist of a number of different components.

Which row shows the components present (/ ) in both a prokaryotic and eukaryotic cell?

Golgi ; cell surface
lysosomes ribosomes
apparatus membrane
A v v
B v v
Cc v v
D v v

Accepted Answer

C

Question 6

6 The diagram shows part of a carbohydrate molecule. CH2OH C O OH HO O HO CH2OH CH2 CH2OH C O C O C O OH OH OH O O HO OH HO HO HO If all the 1, 4 glycosidic bonds in this molecule are hydrolysed, how many water molecules will be used and how many separate glucose molecules will be produced? number of water number of glucose molecules used molecules produced A 1 1 B 2 2 C 3 3 D 4 4

Accepted Answer

B

Question 7

7 A peptide bond is formed between atoms of which two elements? A carbon and carbon B carbon and hydrogen C carbon and nitrogen D hydrogen and nitrogen

Accepted Answer

C

Question 8

8 Which features affect the tensile strength of collagen? 1 the helical structure of collagen chains 2 the small R group of the amino acids in collagen 3 the insoluble nature of collagen 4 the covalent bonds between collagen molecules A 1, 2, 3 and 4 B 1 and 3 only C 1, 2 and 4 only D 2, 3 and 4 only

Accepted Answer

C

Question 9

9 An amino acid can be represented as H R O N C C H H OH where R represents a variable side chain. Which is not a possible side chain? A CH3 B CH2CH2SCH3 C CH2CONH2 D HOCH2CH(OH)CH2OH

Accepted Answer

D

Question 10

10 When red cells leave the lungs, haemoglobin is 98 % saturated. How many molecules of oxygen will be carried by the majority of haemoglobin molecules? A 2 B 4 C 6 D 8

Accepted Answer

B

Question 11

11 A fixed volume of the enzyme catalase was added to a fixed volume of hydrogen peroxide solution. The diagram shows how the rate of the reaction changed over the course of the reaction. initial rate actual rate rate of reaction 00 time Why did the actual rate of reaction decrease over time? A The enzyme active sites become saturated. B The enzymes were denatured. C The product inhibited the reaction. D The substrate molecules were used up.

Accepted Answer

D

Question 12

12 Which levels of protein structure are always involved when competitive and non-competitive inhibitors bind to enzymes? competitive non-competitive A primary, secondary and tertiary secondary B quaternary and tertiary quaternary and tertiary C secondary primary and tertiary D tertiary tertiary

Accepted Answer

D

Question 13

13 The diagram shows the transport of ions across the cell surface membrane. Inside the cell there is a low concentration of sodium ions (Na+) and a high concentration of potassium ions (K+). Outside the cell there is a low concentration of K+ and a high concentration of Na+. The carrier molecule is a pump which exchanges Na+ for K+ ions. inside cell 2 1 cell surface membrane 4 carrier 3 molecule outside cell Which ionic movements are represented by the arrows? active transport active transport diffusion of Na+ diffusion of K+ of K+ of Na+ A 2 3 1 4 B 2 3 4 1 C 3 2 1 4 D 3 2 4 1

Accepted Answer

A

Question 14

14 Plant cells were immersed in solutions of different water potential and left for one hour. Which row shows the effect of the different solutions on the plant cells? water potential of solution compared to plant cells less negative equal more negative A flaccid turgid unchanged B flaccid unchanged turgid C turgid unchanged flaccid D unchanged flaccid turgid

Accepted Answer

C

Question 15

15 Which molecules, found in cell surface membranes, contribute to cell recognition? 1 glycolipids 2 glycoproteins 3 phospholipids A 1, 2 and 3 B 1 and 2 only C 1 and 3 only D 2 and 3 only

Accepted Answer

B

Question 16

16 The cell cycle includes mitosis. Which are features of nuclear division? 1 forms cells of equal size to the parent cell 2 forms genetically identical cells 3 semi-conservative replication of DNA A 2 only B 1 and 2 only C 2 and 3 only D 1, 2 and 3

Accepted Answer

A

Question 17

17 In which process does mitosis not have an important role in living things? A asexual reproduction B growth of cells C increase in size D repair to damaged tissues

Accepted Answer

B

Question 18

18 The diagram shows the chromosomes of a typical plant cell at the metaphase stage of mitosis.

“xX :
a
D4

Which row describes this cell during metaphase?

diploid number (2n) | structures present at metaphase
for the plant cell wall centriole spindle
A 4 v x v
B 8 x v v
Cc 8 v x v
D 16 v v x

Accepted Answer

C

Question 19

19 The table shows the percentages of bases in DNA from various types of cell. percentage of bases in DNA source of DNA adenine guanine thymine cytosine calf thymus 28.2 21.5 27.8 22.5 bull spleen 27.9 22.7 27.3 22.1 bull sperm 28.6 22.2 27.2 22.0 rat bone marrow 28.7 21.4 28.4 21.5 yeast 31.3 18.7 32.9 17.1 What is a valid deduction from these data? A All cells from the same species have approximately the same content of DNA. B Small differences in DNA from different cells have large effects. C The four bases show complementary base pairing. D The structure of DNA is different in yeast and animal cells.

Accepted Answer

C

Question 20

20 Which row shows the correct combination? triplet code codon anticodon A DNA mRNA tRNA B DNA tRNA mRNA C mRNA DNA tRNA D tRNA mRNA DNA

Accepted Answer

A

Question 21

21 A culture of bacteria had all its DNA labelled with the heavy isotope of nitrogen (15N). A sample was taken and spun in a centrifuge. The diagram shows the position of the DNA band at Z in the centrifuge tube. X Y Z The culture was then allowed to reproduce using nucleotides containing the normal isotope of nitrogen (14N). Samples were taken and spun in a centrifuge after one generation and again after two generations. In which pattern would the DNA be found after the first and after the second generations? after first generation after second generation A half at X and half at Y quarter at X, quarter at Z and half at Y B half at X and half at Z quarter at X, quarter at Z and half at Y C all at Y half at X and half at Y D all at Z half at Y and half at Z

Accepted Answer

C

Question 22

22 S and T are products of a biochemical pathway. A different enzyme, coded for by different specific genes, catalyses each step in the pathway. gene 1 gene 2 gene 3 S enzyme 3 enzyme 1 enzyme 2 P Q R enzyme 4 T gene 4 What is the possible outcome to the pathway if a mutation in gene 3 leads to an inactive enzyme? A There is a decrease in the activity of gene 1 and gene 2. B There is an accumulation of product S. C There is an increase in the rate of reaction of enzyme 4. D There is an increase in the production of T.

Accepted Answer

D

Question 23

23 Which processes are involved in transpiration? 1 the diffusion of water vapour from stomata 2 the mass flow of water through the xylem 3 the evaporation of water from spongy mesophyll cells 4 the evaporation of water vapour from exposed leaves A 1, 2, 3 and 4 B 1 and 3 only C 1 and 4 only D 2, 3 and 4 only

Accepted Answer

A

Question 24

24 What is the main function of a companion cell in mature phloem tissue? A providing cytoplasmic contact with the sieve tube element for loading B providing structural support for the sieve tube element C providing the nucleus for cell division in the phloem D providing the source of assimilates for storage

Accepted Answer

A

Question 25

25 Water passes across leaf tissues by different routes as a result of • differences in water potential • the pull transmitted by cohesive forces between water molecules. The diagram shows three routes by which water can travel. epidermal cuticle cell palisade cell xylem vessel cells of the key spongy route 1 =               apoplastic mesophyll route 2 =               vacuolar route 3 =               symplastic cuticle atmosphere epidermal cell Which row correctly identifies why water passes across leaf tissues by the different routes? differences in pull transmitted by water potential cohesive forces A route 1 routes 2 and 3 B routes 1 and 3 route 2 C route 2 routes 1 and 3 D routes 2 and 3 route 1

Accepted Answer

D

Question 26

26 The diagram shows a transverse section of a stem. Which area is the phloem? A D C B

Accepted Answer

B

Question 27

27 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 for this situation? 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 3 so it becomes plasmolysed. A 1 and 2 B 1 and 3 C 2 and 4 D 3 and 4

Accepted Answer

A

Question 28

28 Which of the tissue types below are present in the walls of all blood vessels? 1 collagen 2 elastic 3 endothelial 4 smooth muscle A 1, 2, 3 and 4 B 1, 2 and 4 only C 2 and 3 only D 3 only

Accepted Answer

D

Question 29

29 In mammals, some carbon dioxide is transported by red blood cells in combination with haemoglobin. What is the product of this combination? A carbamino-haemoglobin B carbonic acid C carboxyhaemoglobin D haemoglobinic acid

Accepted Answer

A

Question 30

30 The graph shows pressure changes during a cardiac cycle. 16 Y 14 X 12 10 pressure / 8 kPa 6 Z 4 W 2 0 0.2 0.4 0.6 0.8 time / s Which row correctly identifies W, X, Y, and Z? W X Y Z A atrio-ventricular semi-lunar semi-lunar atrio-ventricular valves close valves close valves open valves open B atrio-ventricular semi-lunar semi-lunar atrio-ventricular valves close valves open valves close valves open C semi-lunar atrio-ventricular atrio-ventricular semi-lunar valves close valves open valves close valves open D semi-lunar atrio-ventricular atrio-ventricular semi-lunar valves open valves close valves open valves close

Accepted Answer

B

Question 31

31 Some babies are born with a hole between the right and left atria. These newly born babies are found to have an increased number of red blood cells. What is the reason for this increase? A More blood is needed because it is pumped faster. B Newly born babies’ haemoglobin has a higher affinity for oxygen. C Newly born babies’ haemoglobin molecules only have one haem group. D There is less oxygen available to the newly born baby.

Accepted Answer

D

Question 32

32 Which row correctly shows the areas of the respiratory tract that contain cartilage, cilia (ciliated epithelium), goblet cells and smooth muscle? cartilage cilia goblet cells smooth muscle A bronchiole, bronchus 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 33

33 In some cases where a person has lung disease, the partial pressure of oxygen in the pulmonary veins is less than the partial pressure of oxygen in the alveoli. Which would contribute to the description above? 1 A high proportion of alveoli are collapsed and do not have enough alveolar capillaries. 2 The degree of alveolar ventilation is too low for the cardiac output supplying most of the alveoli. 3 The partial pressure of oxygen in the pulmonary arteries is lower than in the alveolar air. 4 The rate of diffusion of oxygen from the alveolar air to the surrounding alveolar capillaries is too slow. A 1, 2 and 4 B 1, 3 and 4 C 1 and 2 only D 3 and 4 only

Accepted Answer

A

Question 34

34 Which of the effects listed occur as a result of inhaling both carbon monoxide and nicotine from cigarette smoke? 1 increased heart rate 2 increased risk of cardiovascular disease 3 increased risk of emphysema 4 increased risk of lung cancer A 1, 2 and 3 B 1 and 2 only C 2, 3 and 4 D 3 and 4 only

Accepted Answer

B

Question 35

35 During an investigation on gas exchange, three measurements were made on four people. The efficiency of gas exchange was the same in all four people. Which person, A, B, C or D, absorbed most oxygen during normal breathing? breathing rate tidal volume total lung volume / breaths per minute / dm3 / dm3 A 14 0.6 6.4 B 15 0.6 6.0 C 16 0.5 6.4 D 17 0.5 5.8

Accepted Answer

B

Question 36

36 The data shows how the number of human deaths caused by the bacterium Staphylococcus aureus has changed from 1997 to 2005. Methicillin is an antibiotic used to treat a disease caused by S. aureus. MRSA is methicillin-resistant S. aureus. total number of death total number of death year certificates with S. aureus certificates with MRSA 1997 369 355 1999 452 431 2001 456 681 2003 420 890 2005 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 as there is no treatment. C Resistant strains of MRSA are becoming more common. D S. aureus will always cause humans to die.

Accepted Answer

D

Question 37

37 An enzyme hydrolyses the two heavy polypeptide chains of an antibody molecule. The hydrolysis occurs at the hinge region and breaks the antibody into three fragments. How many of these fragments are able to bind to antigens? A 0 B 1 C 2 D 3

Accepted Answer

C

Question 38

38 The diagram shows the response to a pathogen by the immune system. some form Q S division Q P Q some release R Q Q Q Which row correctly identifies P, Q, R and S? P Q R S A antibody T-lymphocyte antigen plasma cell B antigen B-lymphocyte antibody memory cell C antigen T-lymphocyte antitoxin B-lymphocyte D bacteria B-lymphocyte antibody T-lymphocyte

Accepted Answer

B

Question 39

39 The diagram represents part of the nitrogen cycle. Which process is carried out by nitrifying bacteria? nitrogen in atmosphere A D ammonia C B nitrogen compounds nitrogen compounds nitrogen compounds in soil in plants in animals

Accepted Answer

C

Question 40

40 The diagram shows the flow of energy between organisms in an ecosystem. 1 2 3 4 Which correctly identifies each organism in the ecosystem? 1 2 3 4 A primary decomposers secondary producers consumers consumers B primary secondary producers decomposers consumers consumers C secondary decomposers producers primary consumers consumers D secondary primary decomposers producers consumers consumers

Accepted Answer

C

Question paper20 pages

Mark scheme2 pages

Questions as text

Q1 · Which steps are needed to find the actual width of a xylem vessel viewed in transverse…

Q2 · A specimen is viewed under a microscope using green light with a wavelength of 510 nm

Q3 · Which cell organelle does not contain nucleic acid?

Q4 · The diameter of living cells varies considerably

Q5 · Cells consist of a number of different components

Q6 · The diagram shows part of a carbohydrate molecule

Q7 · A peptide bond is formed between atoms of which two elements?

Q8 · Which features affect the tensile strength of collagen?

Q9 · An amino acid can be represented as H R O N C C H H OH where R represents a variable side…

Q10 · When red cells leave the lungs, haemoglobin is 98 % saturated

Q11 · A fixed volume of the enzyme catalase was added to a fixed volume of hydrogen peroxide…

Q12 · Which levels of protein structure are always involved when competitive and…

Q13 · The diagram shows the transport of ions across the cell surface membrane

Q14 · Plant cells were immersed in solutions of different water potential and left for one hour

Q15 · Which molecules, found in cell surface membranes, contribute to cell recognition?

Q16 · The cell cycle includes mitosis

Q17 · In which process does mitosis not have an important role in living things?

Q18 · The diagram shows the chromosomes of a typical plant cell at the metaphase stage of…

Q19 · The table shows the percentages of bases in DNA from various types of cell

Q20 · Which row shows the correct combination?

Q21 · A culture of bacteria had all its DNA labelled with the heavy isotope of nitrogen (15N)

Q22 · S and T are products of a biochemical pathway

Q23 · Which processes are involved in transpiration?

Q24 · What is the main function of a companion cell in mature phloem tissue?

Q25 · Water passes across leaf tissues by different routes as a result of • differences in…

Q26 · The diagram shows a transverse section of a stem

Q27 · The diagram shows the water potential (Ψ) in some plant cells and in their environment

Q28 · Which of the tissue types below are present in the walls of all blood vessels?

Q29 · In mammals, some carbon dioxide is transported by red blood cells in combination with…

Q30 · The graph shows pressure changes during a cardiac cycle

Q31 · Some babies are born with a hole between the right and left atria

Q32 · Which row correctly shows the areas of the respiratory tract that contain cartilage…

Q33 · In some cases where a person has lung disease, the partial pressure of oxygen in the…

Q34 · Which of the effects listed occur as a result of inhaling both carbon monoxide and…

Q35 · During an investigation on gas exchange, three measurements were made on four people

Q36 · The data shows how the number of human deaths caused by the bacterium Staphylococcus…

Q37 · An enzyme hydrolyses the two heavy polypeptide chains of an antibody molecule

Q38 · The diagram shows the response to a pathogen by the immune system

Q39 · The diagram represents part of the nitrogen cycle

Q40 · The diagram shows the flow of energy between organisms in an ecosystem

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