(i)

Electrical circuit diagram

(ii)

D → Copper wire/conducting wire/connecting wire E → Cell K → Switch/Key P → Resistor/Load

(iii)

Functions of D (Copper wire)

1. To conduct electric current/electricity
2. To connect components of an electrical circuit

Functions of E (Cell)

1. To produce electricity
2. Source of electric current/electric charge
3. Converts chemical energy into electrical energy

Function of K (Switch/Key)

To allow electric current to flow through the circuit depending on whether it is closed or opened

Functions of P (Resistor/Load)

1. To convert electrical energy to other forms of energy
2. To opposre the flow of current through the circuit

(iv)

Energy transformation in electric circuit

Chemical energy is converted into electrical energy.

OR

Chemical energy → Electrical energy

(i)

(ii)

Calcium hydroxide and dilute hydrochloric acid

(iii)

Ca(OH)₂ + 2HCl → CaCl₂ + 2H₂O

(i)

I → Tongue/salivary gland
II → Oesophagus/gullet
III → Stomach
IV → Liver

(ii)

V → Stores bile
VI → Produces enzymes/pancreatic juice

(iii)

Digestion of protein starts at part III (stomach)

(iv)

(i)

A pair of secateurs

(ii)

Uses of secateurs

1. For cutting
2. For trimming
3. For pruning

(iii)

Ways of maintaining the secateurs

1. Greasing/oiling/lubricating metal parts to prevent rusting
2. Cleaning/washing and drying after use
3. Sharpening cutting edges when blunt
4. Repairing/mending broken parts
5. The tool/secateurs should be used for the intended job
6. Tightening loose bolts and nuts
7. Storing tool in cool dry places or tool box

(i)

Neutralization reaction is a chemical reaction between an acid and a base to form salt and water only.

(ii)

(i)

Milky Way is the galaxy in which the solar system is located.

OR

Milky Way is the group of planets and stars which the earth belongs to.

(ii)

Uses of artificial satellites

1. For space exploration
2. For communication/broadcasting/telephone call
3. For weather forecasting/collecting information on the weather
4. For scientific research/experimental research/internet
5. For military purposes/spying/espionage
6. To study the universe
7. For map making
8. For navigation/satellite for navigation

(i)

Habitat is a natural living place of an organism.

OR

Habitat is a place where an organism spends parts/all of its life.

(ii)

Examples of a habitat

1. Aquatic e.g Ponds, streams, lakes, rivers, marine (sea)

2. Terrestrial e.g Forest, Savannah, thicket

3. Arboreal e.g Tree branches, leaves

(i)

Pressure is defined as force per unit area applied in a direction perpendicular/normal to the surface of the object.

OR

Pressure = $\frac{\mathrm{Force\; (F)}}{\mathrm{Area\; (A)}}$

(ii)

Why it is important to sharpen a knife before use

When a knife is sharpened, the cutting edge becomes smaller so that with a little force applied, a larger pressure is exerted for cutting to be easier.

(i)

Differences between metals and non-metals

(ii)

An alloy is a uniform/homogeneous mixture of a metal and another metal or a non-metal.

(ii)

Components of alloys

(i)

Disease vector is an organism that carries and transmit a disease causing organism.

(ii)

(i)

Symptoms of nitrogen deficiency in a tomato plant

1. Yellowing of leaves/chlorosis
2. Stunted growth
3. Weak and slender stems

(ii)

Side dressing is the application of fertilizer at one or both sides of crops on the surface of the soil while the crops are growing.

(i)

Power is the time rate of doing work

OR

Power is the rate of energy dissipation/rate of using energy

OR

Power = $\frac{\mathrm{Work\; done\; (W)}}{\mathrm{Time\; (T)}}$

OR

Power = $\frac{\mathrm{Energy\; transformed\; (E)}}{\mathrm{Time\; (T)}}$

(ii)

The S.I unit of power is watt (W)

(i)

Respiration is the breaking down of glucose in the cells with or without oxygen to release energy and bring out carbon dioxide and water vapour.

(ii)

The types of respiration that occur in humans

Aerobic and Anaerobic respiration

(i)

(ii)

Reasons why copper, silver and gold are mostly used in making ornaments and jewellery

1. They are not reactive metals/will not react with atmospheric gases
2. They have shiny surfaces/lustre

(i)

A fuse is a short piece of wire with a low melting point which serves as a protective/safety device in an electric/electrical circuit.

(ii)

Why a fuse is used in an electrical circuit

It protects appliances when current becomes too high.

(i)

Difference between unicellular organisms and multicellular organisms

Unicellular organisms have only one cell but multicellular organisms have many cells.

(ii)

Reasons why vegetable crops are important to humans

1. Contain nutrients(carbohydrates, vitamins and mineral salts) which are needed by the human body for normal growth
2. Some vegetables contain medicinal substances that treat or control various diseases
3. Some vegetables contain proteins which are used for repair and replacement of worn out cells/tissues
4. Some vegetables contain high amount of cellulose/roughage material that prevent constipation
5. They serve as source of food

(i)

Elements of climate

1. Temperature
2. Humidity
3. Atmospheric pressure
4. Wind speed
5. Wind direction
6. Cloud
7. Rain
8. Sunlight/Intensity of light

(ii)

Difference between climate and weather

Weather is the atmospheric condition of a particular place over a short period of time while climate is the average of the atmospheric conditions over a long period of time.

(i)

Corrosion is the wearing away of surfaces (usually metallic) as a result of chemical reactions between surfaces of material and atmospheric gases.

(ii)

Sublimation is the changing of a substance from solid state directly into the gaseous state.