2019/2020 WASSCE SCIENCE TRIAL

SCIENCE TRIAL QUESTION

1. (a) (i) What is a transistor?
(ii) Explain how a transistor behaves as a switch.
[5 marks]
(b) (i) Explain the term poultry.
(ii) State four reasons for keeping poultry.
[6 marks]
(c) Explain the following terms:
(i) population;
(ii) species.
[5 marks]
(d) (i) What are x-rays?
(ii) State two dangers associated  over
exposure to x-rays.
[4marks]

2. (a) (i) What is plant tissue culture?
(ii) State three advantages of propagating a plant by
tissue culture.
[5 marks]
(b) (i) Explain the term parturition as applied to
animal production.
(ii) State three signs shown by an animal when
parturition is about to occur.
[5 marks]
(c) Draw and label a ray diagram to show how the
image of a point object is seen in a
plane mirror. [5 marks]
(d) A piece of zinc metal was placed in a beaker
containing dilute hydrochloric acid.
(i) Write a balanced chemical equation for the
reaction that took place.
(ii) If 10.4g of zinc was placed in the hydrochloric
acid, determine the
amount, in moles of hydrochloric acid, that would
be required to react with the
zinc completely.
[Zn = 65.4, H = 1, Cl = 35.5]
[5 marks]

3. (a) Explain the following terms as applied to
sound waves:
(i) frequency;
(ii) loudness;
(iii) pitch.
[6 marks]
(b) (i) What is crop rotation?
(ii) State two advantages of crop rotation.
[4 marks]
(c) (i) List three kingdoms used in the
classification
of living things.
(ii) State two reasons for classification of living
things.
[5 marks]
(d) (i) Explain briefly how each of the following
processes occurs:
(i) melting of a solid;
(ii) condensation of a gas.

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