i)

Food chain is the linear relationship between organisms that shows the transfer of energy from one organism to another through feeding and being fed on by another.

ii)

Because plants produce/make their own food through the process of photosynthesis

iii)

Consumer(s)

i)

Name of shadows

ii)

It illustrates that light travels in a straight light

i)

Magnetic field is a region/area around a magnet/moving electric charge within which the force of magnetism acts/can be felt/experienced

ii)

Methods of making magnets

1. By induction
2. By stroking
3. By the use of electricity
4. By hammering/hitting

i)

calcium chloride → CaCl₂

ii)

copper (I) oxide → Cu₂O

iii)

nitrogen (IV) oxide → NO₂

iv)

ammonia → NH₃

i)

Physical properties of soil

1. Texture
2. Structure
3. Temperature
4. Colour
5. Permeability
6. Water
7. Capillarity
8. Organism
9. Drainage
10. Air
11. Strength/consistence
12. Porosity

ii)

Texture of clayey soil

It is smooth/slippery/sticky when wet

(i)

Density is the mass per unit volume of a substance

OR

Density = $\frac{\mathrm{Mass}}{\mathrm{Volume}}$

(ii)

Determination of the density of stone

1. Measure/weigh the mass of stone by means of a beam/chemical balance as M g
2. Fill a large measuring cylinder with water to a suitable level and record the volume as V₁ cm³
3. Tie the stone with thread and gently lower it into the water in the measuring cylinder and record the new volume as V₂ cm³

The density of the stone is then calculated as follows:

Volume of stone = V₂ cm³ - V₁ cm³

Mass of stone = M g

Density = $\frac{\mathrm{Mass}}{\mathrm{Volume}}$

Density of the stone = $\frac{\mathrm{M\; g}}{({\mathrm{V}}_2-{\mathrm{V}}_1){\mathrm{cm}}^3}$

(i)

Alcohol and water → Distillation/fractional distillation

(ii)

Salt and water → Distillation/Evaporation and condensation

(iii)

Powdered charcoal and iron filings → Use of magnet

(iv)

Powdered chalk and water → Filtration/decantation

i)

Functions of leaves to the plant

1. They manufacture food for the plant
2. They help in getting rid of excess water in a plant
3. The exchange of gases between the atmosphere and a plant takes place through the stomata on the leaves

ii)

Functions of roots to the plant

1. They anchor/hold/support the plants firmly in the soil
2. They absorb water and dissolved mineral salts from the soil
3. They store excess food in some plants
4. They are responsible for exchange of gases in some plants in marshy habitats
5. In some plants, the roots are a means of reproduction

i)

eating → voluntary

ii)

walking → voluntary

iii)

sneezing → involuntary

iv)

laughing → voluntary

i)

Differences between a physical change and a chemical change

ii)

Chemical equation for the preparation of carbon dioxide

2HCl + CaCO₃ → CaCl₂ + H₂O + CO₂

i)

A machine is a device that helps us to do work easier/faster.

OR

A machine is a device that enables a small force (effort) to overcome a large force (load).

ii)

Efficiency of a machine = $\frac{\mathrm{Work\; output}}{\mathrm{Work\; input}}$

OR

Efficiency of a machine = $\frac{\mathrm{Output\; energy}}{\mathrm{Input\; enery}}$

OR

Efficiency of a machine = $\frac{\mathrm{Mechanical\; Advantage\; (M.A)}}{\mathrm{Velocity\; Ratio\; (V.R)}}$

(i)

Functions of the cell membrane

1. It protects a cell
2. It allows only selected substances to enter or leave the cell

(ii)

Function of the chloroplast

It contains chlorophyll (green pigment) which traps sunlight for photosynthesis

(iii)

Functions of the nucleus

1. Embodies the genetic information (genes) of the organism
2. Makes cell division or reproduction possible
3. Controls the activites of the cell

(i)

Refraction of light is the bending/change in direction/change in velocity of light as it travels from one medium to another.

(ii)