Cambridge IGCSE™

* 4 5 4 7 9 8 8 2 3 2 *

BIOLOGY 0610/42
Paper 4 Theory (Extended) October/November 2020

1 hour 15 minutes

You must answer on the question paper.

No additional materials are needed.

INSTRUCTIONS
● Answer all questions.
● Use a black or dark blue pen. You may use an HB pencil for any diagrams or graphs.
● Write your name, centre number and candidate number in the boxes at the top of the page.
● Write your answer to each question in the space provided.
● Do not use an erasable pen or correction fluid.
● Do not write on any bar codes.
● You may use a calculator.
● You should show all your working and use appropriate units.

INFORMATION
● The total mark for this paper is 80.
● The number of marks for each question or part question is shown in brackets [ ].

This document has 20 pages. Blank pages are indicated.

DC (JC/CT) 187679/5
© UCLES 2020 [Turn over
 2

1 (a) Sensitivity is one of the characteristics of life. The eye is one of the major sense organs of
vertebrates.

(i) Define the term sensitivity.

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(ii) Define the term sense organ.

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(b) Accommodation (focusing) is one of the functions of the eye.

Fig. 1.1 is a diagram of an eye that is focusing on a distant object.

retina
ciliary muscle

suspensory ligaments

Fig. 1.1

(i) State the name of the part of the retina labelled X.

..................................................................................................................................... [1]

© UCLES 2020 0610/42/O/N/20

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Fig. 1.2 is an incomplete diagram of an eye that is focusing on a near object.

Fig. 1.2

(ii) Complete Fig. 1.2 by drawing the shape of the lens and the light rays from the object to
the retina. [3]

(iii) Describe the roles of the ciliary muscles and suspensory ligaments in focusing on a
distant object, as shown in Fig. 1.1.

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...........................................................................................................................................

..................................................................................................................................... [3]

© UCLES 2020 0610/42/O/N/20 [Turn over

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(c) The eye also controls the amount of light that enters the pupil.

Fig. 1.3 shows an eye in low light and in bright light.

eye in low light eye in bright light

Fig. 1.3

Describe the changes that occur in the eye when the light becomes bright, as shown in
Fig. 1.3.

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............................................................................................................................................. [3]

(d) The change shown in Fig. 1.3 occurs automatically without thought.

State the name given to this type of action.

............................................................................................................................................. [1]

[Total: 15]

© UCLES 2020 0610/42/O/N/20

 Cambridge IGCSE™
* 1 7 0 3 9 2 5 1 3 2 *

BIOLOGY 0610/42
Paper 4 Theory (Extended) May/June 2020

1 hour 15 minutes

You must answer on the question paper.

No additional materials are needed.

INSTRUCTIONS
● Answer all questions.
● Use a black or dark blue pen. You may use an HB pencil for any diagrams or graphs.
● Write your name, centre number and candidate number in the boxes at the top of the page.
● Write your answer to each question in the space provided.
● Do not use an erasable pen or correction fluid.
● Do not write on any bar codes.
● You may use a calculator.
● You should show all your working and use appropriate units.

INFORMATION
● The total mark for this paper is 80.
● The number of marks for each question or part question is shown in brackets [ ].

This document has 24 pages. Blank pages are indicated.

DC (JC/CT) 180482/4
© UCLES 2020 [Turn over
 2

1 Homeostasis is the maintenance of a constant internal environment.

(a) Human skin is involved in the maintenance of a constant internal body temperature.

(i) Skin is an organ.

State why the skin is an organ.

...........................................................................................................................................

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..................................................................................................................................... [1]

(ii) State the name of the organ that coordinates the control of body temperature.

..................................................................................................................................... [1]

Fig. 1.1 shows a diagram of a section through human skin.

A
F

Fig. 1.1

(iii) State the names of structures A, B and C in Fig. 1.1.

A ........................................................................................................................................

B ........................................................................................................................................

C ........................................................................................................................................
[3]

© UCLES 2020 0610/42/M/J/20

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(iv) Structure D is a shunt vessel and E is an arteriole.

Describe how these blood vessels are involved in maintaining a constant internal body
temperature in a cold environment.

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..................................................................................................................................... [3]

(b) Energy is used to maintain body temperature.

State three other uses of energy in humans.

1 ................................................................................................................................................

2 ................................................................................................................................................

3 ................................................................................................................................................
[3]

[Total: 11]

© UCLES 2020 0610/42/M/J/20 [Turn over