(i)

I = beaker
II = residue/particles/cotton wool/mixture/filter paper
III = filtrate

(ii)

Methods of Separation

(iii)

Class of mixtures

1. Solid - liquid mixture
2. Liquid - solid mixture

(iv)

Reason for the class of mixture

Because there is residue on the filter paper and filtrate in the beaker

(v)

possible component of the mixture in set-up B

- iron fillings/any magnetic substance
- powdered sulphur
- sand
- powdered chalk
- powdered charcoal
- any non-magenetic substance

(vi)

Function of part labelled IV (Retort/Clamp Stand)

It holds the funnel in place/holds the clamp

(i)

The system illustrated is respiratory system

(ii)

Name of the parts labelled

I = Larynx/Voice Box
II = Trachea/windpipe
III = Bronchus
IV = lung

(iii)

Role of the part labelled I (Larynx)

1. Allows air to pass through it/breathing
2. Prevent food and drink from blocking the airways
3. Produces sound/phonation

(iv)

Diseases of the respiratory system

1. Tuberculosis/T.B.
2. Bronchitis
3. Pneumonia
4. Whooping cough
5. Lung cancer
6. Influenza
7. Asthma
8. Bronchiectasis
9. Idiopathic pulmonary fibrosis/pulmonary disease
10. Common cold
11. Covid-19

(i)

Rain gauge

(ii)

Name of the parts labelled

I = funnel
II = measuring cylinder
III = rain water/water

(iii)

Use of the parts labelled I (funnel) and II (measuring cylinder)

I - directs rain water into the measuring cylinder

II - use to measure the amount/volume of rain water/collect rain water

(iv)

Ecological factor measured

Rainfall/amount of rainfall/rain

(v)

Importance of ecological factor measured

1. Protects plants roots from injury
2. Causes erosion
3. Causes leaching
4. Needed for seed germination
5. Promotes activities of soil organisms
6. Aids in easy tillage of soil
7. An agent of weathering of rocks in the soil
8. Dissolves plant nutrients for easy absorption
9. Makes soil fertile
10. Determine the type of crop to grow
11. Used for photosynthesis

(vi)

Handfork

(vii)

Use to loosen hard soil surface after heavy rainfall

(i)

Name of the components labelled

I = cell
II = switch/key
III = lamp/bulb

(ii)

Type of arrangement of resistors (R) in B is parallel

(iii)

A - makes III/bulb dim
B - makes III/bulb bright

(iv)

Reasons

A - the resistors in series have an increased resistance

B - the resistors in parallel have decreas resistance hence keep the bulb bright

(i)

A solution is a uniform/homogeneous mixture of a solute and a solvent where the solute completely disappear from sight in the solvent (liquid)

OR

A solution is formed when a solute dissolves in a solvent to form a uniform/homogeneous mixture.

(ii)

(i)

Characteristics which are common to all living things

1. Respiration
2. Excretion
3. Growth
4. Reproduction
5. Nutrition
6. Sensitivity

(ii)

(i)

Defects of the eye

1. Long sightedness/Hypermetropia
2. Short sightedness/Myopia
3. Astigmatism/Presbyopia

(ii)

Correction of defects

Long sightedness/Hypermetropia

Wearing converging/convex lens

Short sightedness/Myopia

Wearing diverging/concave lens

Astigmatism/Presbyopia

Medical treatment/use of special lenses

i)

Soil erosion is the washing away/removal of the top soil by water or wind

ii)

Methods of controlling soil erosion

1. Terracing
2. Strip cropping
3. Contour ploughing
4. Wind breaks/afforestation/tree planting
5. Mulching
6. Cover cropping
7. Practising crop rotation
8. Bush fallowing/land rotation

α)

Adaptation is the ability of an organism to survive in a given environment using special features

β)

Endangered species are plants and animals facing extinction/numbers are decreasing.

i)

Examples of hard water

1. Well water
2. Sea water/lagoon water
3. Borehole

ii)

Why it is advisable to drink hard water

1. It contains ions of calcium which are good for strong bones and teeth
2. It helps to reduce heart ailments

i)

Magnetic field is the area around a magnet where the effect of the force of a magnet can be felt/experienced.

ii)

Methods of making magnets

1. Hammering/strong heating in the earth's magnetic field
2. Stroking
3. Electrical
4. Induction

(i)

A machine is a device that makes work easier or faster

OR

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

(ii)

Mechanical advantage of a machine is the ratio of the load to the effort needed to raise the load

OR

Mechanical advantage (M.A) = $\frac{\mathrm{Load\; (L)}}{\mathrm{Effort\; (E)}}$

(iii)

Velocity ratio of a machine is the ratio of the distance moved by the effort to the distance moved by the load

OR

Velocity ratio (V.R) = $\frac{\mathrm{Distance\; moved\; by\; effort}}{\mathrm{Distance\; moved\; by\; load}}$

(i)

General causes of diseases

1. Consequences of malnutrition
2. Vitamin or mineral salts deficiency
3. Air or water pollution
4. Chemical/food poisoning
5. Defects resulting from injuries
6. Poor sanitation
7. Poor personal hygiene
8. Not covering food properly
9. Pouring faeces or going to nature's call around
10. Throwing empty tins/cans about
11. Drinking bad/untreated water

(ii)

Ways by which diseases can be prevented

1. Washing hands before eating
2. Washing hands with soap after visiting toilet
3. Observing personal hygiene
4. Proper disposal of refuse/sewage
5. Keeping the environment clean
6. Drinking safe/treated water
7. Vaccination/immunization against diseases
8. Exercising the body

i)

Fertilization is the fusion of the male and female sex cells to form a zygote.

ii)

The processes that lead to fertilization in humans after mating

1. The sperms move through the vagina, cervix and uterus to the fallopian tube
2. Only one of the millions of sperms succeeds to penetrate the membrane of the ovum
3. The nuclei of the sperm and ovum unit/fuse to form a zygote

i)

Density of a substance is the mass per unit volume of the substance.

OR

Density = $\frac{\mathrm{Mass\; (M)}}{\mathrm{Volume\; (V)}}$

ii)

Determination of the density of a 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)

An element is a substance that cannot be broken down/split into simpler substances by any known chemical means.

ii)

i)

Mixture is what is formed when two or more substances are put together/combine physically.

ii)

Why some mixtures are thoroughly stirred before they are used

Mixtures are thoroughly stirred to make a homegenous/uniform mixture

OR

Mixtures are thoroughly stirred to make even/uniform concentration

i)

Reflection of light is the bouncing of light from a surface.

ii)

Characteristics of the images formed by plane mirrors

1. It is erect (upright)
2. It is virtual
3. It is laterally inverted
4. Same distance behind mirror as object is in front of mirror
5. Same size and shape as the object

i)

Fertilizer is any substance which is applied to the soil or plant to supply nutrients for plant growth.

ii)

Examples of an inorganic fertilizer

1. Urea
2. Muriate of potash
3. Single super phosphate (SSP)/sulphate of ammonia
4. NPK

i)

Indiscriminate sex is the act of having sexual intercourse with different/many/multiple partners.

ii)

Dangers of indiscriminate sex on humans

1. Acquiring sexually transmitted diseases
2. Unwanted pregnancy/becoming pregnant
3. Causing abortion