(a) Explain each of the following observations in nature:
(i) In the depths of the ocean where it is always dark,there are no green plants.
(ii) On an island where there areno insects and birds,the pawpaw plant produces onlyflowers but no fruits [6 marks]
(b) Describe how soil is formed. [4 marks]
(c) (i) State the laws of reflection
(ii) Draw a labelled diagram to show the reflection of light on a plane mirror [5 marks]

(a) A child is found not to be able to see at night
(i) What deficiency disease may the child be suffering from?
(ii) What food nutrient is the child lacking?
(iii) List two sources of food substances that can provide the nutrient the child lacks. [4 marks]

(b) (i) What is an atom?
(ii) Name the components of an atom which determines each of the following quantities.
(α) mass of an atom
(β) charge of an atom
(iii) Why is an atom electrically neutral? [5 marks]

(c) (i) What is friction?
(ii) Give two bad effects of friction.
(iii) Give two situations where friction is an advantage [6 marks]

(a) (i) Explain heredity
(ii) Give two examples of heredity characters [5 marks]

(b) Explain whether each of the following processes is a chemical change or a physical change:
(i) Rusting;
(ii) Burning;
(iii) Filtration;
(iv) Expansion of copper
[4 marks]

(c) (i) What is a simple machine?
(ii)Name two types of simple machines
(iii) Explain why the efficiency of a machine cannot be equal to 100% [6 marks]

(a) Study the organisms listed below: Earthworm; Sheep; Cassava plant; Grasshopper; Man; Hen.
Draw a food chain using four of the organisms [4 marks]

(b) (i) Name four types of forces apart from friction.
(ii) Give three effects of a force [7 marks]

(c) A certain pupil in a classroom can see clearly on the blackboard only when he sits at the front.
(i) State the eye defect the child is suffering from. (ii) Explain why the child is unable to see when he is far from the blackboard.
(iii) How can the defect be corrected?