Sem Exam QP

SUNWAY COLLEGE KUALA LUMPUR

University of Cambridge International Examinations
General Certificate of Education
AS Semester Examination for Jan 16 Intake

CANDIDATE TEACHER’S NAME _________________
NAME
CLASS _________________
CENTRE
NUMBER

BIOLOGY 9700/21
Paper 2 AS Structured Questions May/June 2016
1 hour 15 min
Candidates answer on the Question Paper.
Addition Materials: Electronic calculator

Ruler

READ THESE INSTRUCTIONS FIRST

Write your Centre number and candidate name in the spaces provided at the top of this page.
Write in dark blue or black ink.
You may use a soft pencil for any diagrams, graphs or rough working.
Do NOT use red ink, staples, paper clips, highlighters, glue or correction fluid.

Answer all questions.
At the end of the examination, fasten all your work securely together.
The number of marks is given in brackets [ ] at the end of each question or part question.

For Examiner’s Use
1
2
3
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6

Total

This document consists of 15 printed pages and 1 blank page.

[Turn over]

2 For
Examiner's
Answer all the questions.
1. Some seeds contain lipids. A triglyceride is one type of lipid. Use

(a) Fig. 1.1 shows the structure of a triglyceride molecule.

Fig. 1.1

(i) A triglyceride molecule is formed by condensation. From how many molecules is
this triglyceride formed?

[1]

(ii) The structure of a phospholipid molecule is different from that of a triglyceride.

Describe how a phospholipid is different.

__________________________________________
__________________________________________
__________________________________________
________________________________________ [2]

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3 For
(b) Fig. 1.2 is a drawing of the bacterium Vibrio cholerae the causative agent of cholera. Examiner's

Use

Fig. 1.2

(i) In Fig. 1.2, draw a label line and mark X to the structure that is primarily made up
of phospholipid.
[1]

(ii) In terms of water potential, explain what happens to the bacterial cell when it is
placed into an environment containing pure water.

__________________________________________
__________________________________________
__________________________________________
__________________________________________
__________________________________________
__________________________________________
________________________________________ [3]

[Total: 7]

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4 For
Examiner's
2. Fig. 2.1 is a drawing made from an electron micrograph of a cell from the ciliated
epithelium of the bronchus. Use

Fig. 2.1

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5 For

Examiner's
Use

(a) Complete the table below by writing the appropriate letter from Fig. 2.1 to indicate the
structure that carries out each of the functions listed. The first one has been
completed for you.

function structure

facilitated diffusion of glucose B

creates a current to move mucus

aerobic respiration

made of loops of DNA from several chromosomes

allows the entry of ATP and exit of mRNA

packages proteins into lysosomes

[5]

(b) Calculate the actual width of the cell in Fig. 2.1.
Show your working.

_____________________________ [2]

(c) With reference to Fig. 2.1, suggest why structure X is not a continuous structure
projected from the cell.

__________________________________________ [1]

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6 For
Fig. 2.2 shows an electron micrograph of a bacteria, Bacillus subtilis. Examiner's

Use

Fig. 2.2

(d) Name three structures, present in cell shown in Fig. 2.1, which are not present in the
cell shown in Fig. 2.2.

1 __________________________________________
___________________________________________
2 __________________________________________
___________________________________________
3 __________________________________________
__________________________________________ [3]

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7 For
Examiner's
(e) In the industry, B. subtilis is genetically engineered to produce the amylase enzyme
in large quantities. Use

Fig. 2.3 shows the activity of amylase enzyme extracted from two different B. subtilis
strains, A and B. Both of the enzymes are able to catalyse the formation of product
from a similar substrate.

Fig. 2.3

(i) Use the graph to estimate the Michaelis-Menten constant (KM) for both enzymes.

KM for amylase from bacteria A __________________
KM for amylase from bacteria B __________________

[2]

(ii) Explain, in terms of KM values, the interaction of both the enzymes towards their
substrate.

__________________________________________
__________________________________________
________________________________________ [2]

(iii) Substance Y is an inhibitor to the enzyme extracted from bacteria A. Substance Y
binds to a site other than the active site of the enzyme. Using the graph from
Fig. 2.3, draw a curve which represents the effect of this inhibition.
[1]

[Total: 16]

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8 For
Examiner's
3. During a sporting event an athlete may have to carry out anaerobic respiration in addition
to aerobic respiration to produce sufficient ATP. Use

(a) Fig. 3.1 outlines both processes in a muscle cell and shows how a liver cell is linked
to these processes.

Fig. 3.1

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9 For
You may refer to Fig. 3.1 in answering questions (i) to (iv) below. Examiner's

Use

(i) Glucose produced in the liver cell can be released into the blood to maintain
blood glucose concentration.

State one use of glucose within the liver cell.

__________________________________________
________________________________________ [1]

(ii) Suggest why anaerobic respiration is said to be less efficient than aerobic
respiration.

__________________________________________
__________________________________________
__________________________________________
________________________________________ [2]

(iii) Complete the table to indicate, within the muscle cell, the precise locations of
glycolysis, the link reaction, the Krebs cycle and oxidative phosphorylation.

process precise location
glycolysis

link reaction

Krebs cycle

oxidative phosphorylation

[4]

(iv) Additional oxygen is required in the metabolic pathways involved in the
conversion of lactate to glucose.

State the term given to this additional oxygen.

________________________________________ [1]

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10 For
(b) Complete the following passage about ATP by writing in the missing words. Examiner's

Use

All living organisms use energy. The most common immediate source of energy is
adenosine triphosphate (ATP) which is used in every cell for the movement of ions
against a concentration gradient, known as _________________________ . ATP is
known as the universal currency of energy.

ATP is a phosphorylated nucleotide which is known as a ‘high energy’ molecule. It is
made of an organic base, adenine, a 5 carbon sugar named
_________________________ and three phosphate groups. ATP is very soluble in
_________________________ and easily transported within the cell. The removal of
the outer phosphate group by the process of _________________________
releases energy. The energy released as a result of this reaction can be channelled
directly into other reactions in the cell.

A certain proportion of this energy is lost as _________________________ . ATP is
continually broken down and is reformed at a fast rate by the process of respiration.

[5]

[Total: 13]

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11 For
4. Fig. 4.1 shows a cross-section of the heart at the level of the valves. Examiner's

Use

Fig. 4.1
(a) Complete the following flow chart to show the pathway of blood through the heart.

[2]

(b) Explain how the valves P and Q ensure one-way flow of blood through the heart.

___________________________________________
___________________________________________
___________________________________________
__________________________________________ [2]

(c) State two ways in which the composition of blood entering the right atrium is
different to blood entering the left atrium.

1 __________________________________________
___________________________________________
2 __________________________________________
__________________________________________ [2]

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12 For
Examiner's
Lugworms live in mud where the partial pressure of oxygen is low. Fig. 4.2 shows
oxygen dissociation curves for a lugworm and for a human. Use

Fig. 4.2

(d) Explain the advantage to the lugworm of having haemoglobin with a dissociation
curve in the position shown.

___________________________________________
___________________________________________
___________________________________________
__________________________________________ [2]

[Total: 8]

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13 For
Examiner's
5. A doctor measured the volume of air in the lungs of two people over a period of 7
seconds. Both people were resting. One person was healthy. The other had Use
emphysema. The results are shown in Table 5.1.

Table 5.1
volume of air in lungs / dm3

time / s person A person B

0 6.5 7.0
1
2 3.8 6.0
3
4 3.0 5.6
5
6 2.3 5.1
7
2.0 4.8

1.7 4.5

1.6 4.2

1.6 3.9

(a) The two people were breathing out during the time shown. What evidence in the
table supports this statement?

___________________________________________
__________________________________________ [1]

(b) Calculate the rate at which person A breathed air out of his lungs between 0 and 3
seconds.
Show your working.

answer ___________________________ dm3 s–1 [2]

(c) Person B has emphysema. Give one piece of evidence from the table that shows
this.

___________________________________________
__________________________________________ [1]

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14 For

Examiner's
Use

(d) Emphysema reduces the efficiency of gas exchange in the lungs. Explain why.

___________________________________________
___________________________________________
___________________________________________
___________________________________________
___________________________________________
___________________________________________
___________________________________________
___________________________________________
___________________________________________
__________________________________________ [4]

(e) The alveoli in the lungs are lined by a squamous epithelium.

Explain why gas exchange occurs in alveoli and not in the bronchus.

___________________________________________
___________________________________________
___________________________________________
___________________________________________
___________________________________________
__________________________________________ [3]

[Total: 11]

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15 For
6. Fig. 6.1 is a photomicrograph of a transverse section through the leaf of a C4 plant. Examiner's

Use

Fig. 6.1

(a) Identify structures A and B.

A __________________________________________
B _________________________________________ [2]

(b) Describe the pathway taken by water from the cytoplasm of the root hair cell to a
xylem vessel in the centre of the root.

___________________________________________
___________________________________________
___________________________________________
___________________________________________
___________________________________________
__________________________________________ [3]

[Total: 5]

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16 For
BLANK PAGE Examiner's

Use

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