MAHATMA GANDHI SECONDARY SCHOOLS /

RABINDRANATH TAGORE SECONDARY SCHOOL

Second Term Examinations 2020

CANDIDATE
NAME

CANDIDATE INDEX
CLASS I NUMBER

BIOLOGY 9700

GRADE 13 - Advanced Subsidiary and Advanced level Nov 2020

Paper 1 Multiple Choice Question 1 hour

Candidates answer on the Multiple Choice Grid Paper. 40 marks

READ THESE INSTRUCTIONS FIRST

• Write in soft pencil.
• Do not use staples, paper clips, glue or correction fluid.
• Write your name, centre number and candidate number on the Answer Sheet in the spaces
provided unless this has been done for you.
• There are forty questions on this paper. Answer all questions. For each question there are four
possible answers A, B, C and D.
• Choose the one you consider correct and record your choice in soft pencil on the separate
Answer Sheet.
• Read the instructions on the Answer Sheet very carefully.
• Each correct answer will score one mark. A mark will not be deducted for a wrong answer.
• Any rough working should be done in this booklet.
• Electronic calculators may be used.

• Check that the question paper consists of 16 printed pages.

This document consists of 16 printed pages.

MGSS/RTSS 2020 [Turn over]

Page 1 of 16
1. The diagram shows a slide of a transverse section of a stem. This diagram is the same
size as the actual slide.

A student observed this slide using a light microscope at a magnification of ×40. The
student made a plan drawing of the stem, which was 20 cm in diameter. The student
labelled the plan ‘Transverse section of a stem ×40’.
Which statement explains why this label is not correct?

A The actual size of the stem should have been checked using an eyepiece graticule.
B The actual size of the stem was smaller under low power.
C The image size in the drawing was larger than ×40.
D The image size in the drawing was smaller than ×40.

2. Which statement explains why it is necessary to use an electron microscope to see the
cristae of a mitochondrion?

A The magnification of the electron microscope is greater than that of the light
microscope.
B The membranes of the cristae are separated by a distance greater than 200 nm.
C The resolution of a student microscope using daylight is too low.
D The wavelength of an electron beam is longer than the wavelength of light.

3. Some features of cells are listed.

1 cell wall 2 cell surface membrane 3 ribosomes

Which features can be found in plant cells and in prokaryotic cells?

A 1, 2 and 3 B 1 and 2 only C 1 and 3 only D 2 and 3 only

Page 2 of 16
4. In unsaturated 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

5. What is the minimum number of carbon atoms in an amino acid?

A1 B2 C3 D4

6. A solution containing equal masses of amylose and amylopectin is completely

hydrolysed. Which molecules will be found after the hydrolysis?
A α-glucose only B β-glucose only
C equal masses of α-glucose and β-glucose D more α-glucose than β-glucose

7. Which statement about the properties of water is correct?

A Bonds between hydrogen atoms cause water to have a high specific heat capacity.
B The high latent heat of vaporisation of water is due to the presence of hydrogen bonds.
C The high specific heat capacity of water causes cooling during evaporation.
D Water can dissolve amylopectin as it has hydrophilic side chains.

8. Which statement about the effect of substrate concentration on the activity of an

enzyme is correct?
A Above a certain concentration of substrate an enzyme reaches its maximum rate of
reaction.
B At high concentration of competitive inhibitor increasing the substrate concentration
has no effect.
C At high substrate concentration a non-competitive inhibitor no longer affects the
enzyme activity.
D The higher the concentration of substrate the faster an enzyme can catalyse a reaction

Page 3 of 16
9. Lysozyme is an enzyme found in tears and saliva.
Which statement refers only to the tertiary structure of lysozyme?

A A section of the molecule consists of an α-helix.

B It consists of a single polypeptide.
C It is 129 amino acids long.
D The 35th and 52nd amino acids help form the active site.

10. The graph shows the effect of an enzyme on a reaction.

Which labels are correct?

A X is the reaction without the enzyme, W is the activation energy.
B X is the reaction with the enzyme, Z is the overall energy change.
C Y is the reaction with the enzyme, W is the difference in activation energy.
D Z is the energy gained by the product, W is the activation energy with the enzyme.

11. What determines the specificity of an enzyme?

1 the bonding between R groups of the polypeptide
2 the optimum pH of the enzyme
3 the peptide bonds between amino acids of the polypeptide
4 the shape of the substrate molecule
A 1, 2, 3 and 4 B 1 and 3 only C 1 only D 2, 3 and 4 only

Page 4 of 16
12. What describes a carrier protein in cell surface membranes?

A a glycoprotein that is found on the outer surface of the membranes allowing cell
recognition
B a glycoprotein that is involved in moving substances through the membranes by both
active and passive transport
C a protein that allows the attachment of signaling molecules which brings about changes
within the cell
D a protein that is involved in moving substances through the membranes by passive
transport through water-filled pores

13. The indicator cresol red changes from red to yellow when put into an acid. Some
blocks of agar containing cresol red were cut to different sizes and put in an acid. All other
variables were kept constant. The blocks were measured in mm. Which block became
completely yellow most quickly? (all reading below in mm)

A 3 ×30 ×30 B 6×6 ×6 C 6×12×12 D 12×12×12

14. The diagram shows a plant cell.

The plant cell is put into a solution with a water potential less negative than the cell
contents.
What will happen to the appearance of the cell?

Page 5 of 16
15. The diagram shows the fluid mosaic model of membrane structure.

Which molecules in the membrane are identical?

A 1, 2 and 3 B 1 and 4 C 2 and 3 only D 4 only

16. The diagram shows the cell cycle of a mammalian cell.

Checkpoints in the cell cycle of mammals prevent the cycle from continuing when
mistakes are made or DNA is damaged. Four of the checkpoints are described.

1. Mitosis is blocked if DNA replication is incomplete.

2. Anaphase is blocked if the assembly of chromatids on the spindle is unsuccessful.
3. DNA replication is blocked if DNA is damaged.
4. DNA replication stops if damage to DNA has not been repaired.

In which phases of the cell cycle do these checkpoints occur?

Page 6 of 16
17. The photomicrograph shows cells in different stages of mitosis.

Which statements are correct?

1. Cell T shows metaphase.
2. DNA replication occurs in cell R.
3. The amount of DNA in cell P is the same as in cell T.
4. The correct order for the stages is S→R→T→P→Q.
A. 1, 2 and 3 B 1, 2 and 4 C 1, 3 and 4 D 2, 3 and 4

Page 7 of 16
18. The diagram shows the structure of one chromosome.

Which row is correct?

19. When a gene mutation occurs, which of the following may be altered, resulting in the
production of a non-functional protein?
1 amino acid sequence
2 DNA nucleotide sequence
3 mRNA nucleotide sequence
A 1, 2 and 3 B 1 and 2 only C 2 and 3 only D 2 only

20. Which is the correct DNA triplet on the original DNA template that codes for the amino
acid histidine (His)?

A CAU B CGT C GTA D GUA

Page 8 of 16
21. Which statement about nucleotides is correct?

A Adenine and guanine are pyrimidines.

B ATP is a phosphorylated nucleotide.
C Purines have a single ring structure.
D Uracil replaces cytosine in RNA.

22. In a genetic engineering experiment a piece of double-stranded DNA containing

6000 nnucleotides coding for a specific polypeptide is transcribed and translated.

What is the total number of amino acids in this polypeptide?

A 500 B 1000 C 2000 D 3000

23. Bacteria were grown in a medium containing 15N. After several generations, all of the
DNA contained 15N. Some of these bacteria were transferred to a medium containing the
common isotope of nitrogen, 14N. The bacteria were allowed to divide once. The DNA of
some of these bacteria was extracted and analysed. This DNA was all hybrid DNA
containing equal amounts of 14N and 15N.
In another experiment, some bacteria from the medium with 15N were transferred into a
medium of 14N. The bacteria were allowed to divide three times. The DNA of some of
these bacteria was extracted and analysed.
What is the composition of this DNA?

Page 9 of 16
24. Which processes are involved in the mass movement of water through xylem vessels?

1. Hydrogen bonding between water molecules

2. Cohesion between water molecules
3. Adhesion between water molecules and lignin

A 1, 2 and 3 B 1 and 2 only C 1 and 3 only D 2 and 3 only

Page 10 of 16
25. The diagrams show transverse sections of parts of a plant.

In the transverse sections, which tissues transport water and which tissues transport
sucrose?

Page 11 of 16
26. Which diagram represents the effect of atmospheric humidity on the rate of
transpiration?

27. Water that is present inside a root hair cell may leave the cell and pass to the vascular
tissue.
Through which route must the water travel?
A apoplast B plasmodesmata
C symplast D vacuoles

28. Which of these statements about the formation of haemoglobinic acid are correct?

1. It can only occur with the dissociation of oxygen from haemoglobin.

2. It removes excess hydrogen ions preventing blood becoming too acidic.
3. It is linked to the action of carbonic anhydrase.

A 1, 2 and 3 B 1 and 2 only C 1 only D 2 and 3 only

Page 12 of 16
29. The diagram is an external view of the mammalian heart and the associated blood
vessels.

Which statement about the blood vessels associated with a normal, healthy heart is
correct?
A P and Q carry blood with more oxyhaemoglobin than haemoglobin.
B P and R carry blood that is saturated with oxygen.
C S and P carry blood with a low oxygen concentration.
D S and R carry blood with more haemoglobin than oxyhaemoglobin.

30. A student was asked to describe the differences between four microscope slides of
sections taken from different parts of the gas exchange system.

Slide 1 not present: cartilage, glands present: few goblet cells, ciliated epithelial cells,
smooth muscle
Slide 2 present: incomplete cartilage rings, glands, goblet cells, ciliated epithelial cells,
smooth muscle
Slide 3 not present: cartilage, glands, goblet cells, smooth muscle present: squamous
epithelial cells
Slide 4 present: plates of cartilage, glands, goblet cells, ciliated epithelial cells, smooth
muscle

Page 13 of 16
Which is the correct identification of the parts of the gas exchange system?

31. The graph shows changes in percentage saturation of haemoglobin with oxygen in
the blood of a human and of another animal. The partial pressure of carbon dioxide
remains constant at 1.0 kPa and the temperature is constant at 25 °C.

Which conclusion is supported by the graph?

A At 25 °C the affinity of haemoglobin for oxygen increases more in humans than in the
animal.
B Haemoglobin in the animal carries less oxygen than haemoglobin in the human.
C Oxygen is more easily released from haemoglobin in animal muscle than in human
muscle.
D The Bohr effect in the haemoglobin of the animal is greater than in human haemoglobin.

32. Which row correctly describes the short-term effects of carbon monoxide and nicotine
on the body of a smoker?

Page 14 of 16
33. Which symptoms may be seen in a person affected by chronic obstructive pulmonary
disease (COPD)?
1 persistent cough 2 less elastic alveoli
3 increased risk of lung infection 4 shortness of breath
A 1, 2, 3 and 4 B 1, 2 and 3 only C 2, 3 and 4 only D 1 and 4 only

34. Which factors would help a person to adjust from living at a low altitude to living at a
high altitude?
1. Formation of fewer red blood cells
2. An increase in the oxygen-carrying capacity of the blood
3. An increase in the output of blood by the heart
A 1, 2 and 3 B 1 and 2 only C 1 and 3 only D 2 and 3 only

35. Which two diseases are transmitted by airborne droplets?

A cholera and malaria B malaria and measles
C measles and tuberculosis (TB) D tuberculosis (TB) and cholera

36. More people are exposed to the risk of contracting malaria due to an increase in the
distribution of Anopheles mosquitoes. What could be the cause of this increase?

A drug resistance in Plasmodium B global warming

C insecticide resistance D no effective vaccine

Page 15 of 16
37. Which features do the causative agents of measles, malaria and tuberculosis (TB)
have in common?

38. Which method of gaining immunity can be described as natural active immunity?
A feeding on colostrums B inhaling the chicken pox virus
C injection with antibodies D through the placenta

39. Why is it necessary for a person with a bacterial infection to take antibiotics at evenly
spaced time intervals?
A to increase the concentration of antibiotic slowly to a level which is lethal to the bacteria
B to maintain a concentration of antibiotic in the body which is lethal to the bacteria
C to prevent the development of resistant strains of bacteria
D to select and kill the resistant strains of bacteria

40. Which row correctly identifies the roles of B-lymphocytes and T-lymphocytes?

Page 16 of 16