(i)

The law of floatation states that a floating body displaces its own weight of the fluid in which it floats.

(ii)

Characteristics of the image formed by a plane mirror

The image formed by a plane mirror is:

1. upright/erect
2. at equal distance from the mirror as the object
3. virtual/behind the mirror
4. Laterally inverted
5. Equal in size as the object

(i)

Reason for providing feed and water in clean containers

To avoid contamination

(ii)

Reason for ensuring a routine deworming programme

To prevent worm infestation

(iii)

Reason for practicing rotational grazing

To prevent pest build-up/break the cycle of pest infestation

(iv)

Reasons for avoiding overstocking of animals

1. To prevent fighting or cannibalism
2. To ensure proper spacing
3. To avoid spread of diseases
4. To ensure proper ventilation

(v)

Reasons for preventing sheep from feeding on wet pastures

1. To prevent diarrhoea
2. To prevent infestation by worms

(i)

Water and sodium

2Na + 2H₂O → 2NaOH + H₂

(ii)

Water and magnesium

Mg + 2H₂O → Mg(OH)₂ + H₂

OR

Mg + H₂O → MgO + H₂

(i)

Causes of uneven heating of the earth's surface

1. Curvature of the earth's surface/the angle at which the sun's rays strike the earth/the earth is a sphere with equator heated more intensely than the poles
2. Revolution of the earth around the sun
3. Rotation of the earth on its axis
4. Differences in land and sea temperatures
5. The earth covered primarily with land and water which get heated and cool at different rates

(ii)

Characteristics of westerlies

1. They are hot air
2. They are from the equator to the poles
3. They have low density

(i)

Functions of the mammalian teeth

(ii)

How the structure of the incisor is adapted for its function

It has sharp or chisel-shaped edge

How the structure of the canine is adapted for its function

It has pointed edge/it is conical

How the structure of the molar is adapted for its function

It has flat/cusped/ridged surface

(i)

Diseases that affect poultry

1. Gumboro
2. Newcastle
3. Marek's/fowl paralysis
4. Fowl pox/Avian flu/bird flu
5. Pullorum/bacillary white diarrhea
6. Foot rot
7. Ring worm
8. Chronic respiratory disease
9. Fowl typhoid

(ii)

Diseases that affect cattle

1. Foot-and-mouth disease
2. Rinderpest
3. Cervico-vaginitis
4. Anthrax
5. Brucellosis/contagious abortion
6. Mastitis
7. Babesiosis (red water/tick fever)
8. Rabies
9. Tuberculosis
10. Footrot
11. Mad-cow disease

(i)

Ways in which parallel wiring system in households is important

1. The same voltage is supplied to all lamps/all lamps receive their required currents/it ensures that lamps are bright
2. When a lamp blows, it does not affect the functioning of other lamps/it is safe/reliable
3. Lamps are controlled by individual switches/lamps can be turned on and off independently
4. It is simple to design
5. It allows additional components/lamps

(ii)

Energy = Power x Time

1 hour = 60 x 60 s = 3600s

Note: the S.I unit for time is second hence you have to convert the hour to second.

Power = 2kW = 2 x 10³W

Energy = 2 x 10_{3 x 3600 J}

Energy = 7,200,000 J

Energy = 7.2 x 10⁶ J

(i)

Decombing is the removal of combs of poultry/young birds to prevent restlessness infection caused by flies or for them to grow fat or avoid being pecked by others.

(ii)

Reasons for castrating farm animals

1. To remove odour
2. To fatten the animal/to facilitate growth
3. To prevent sexually transmitted diseases/sexual desire
4. To make animal docile/to reduce aggression/reduces sexual desire
5. To prevent in-breeding/indiscriminate mating
6. Minimizes stress on the animal, when done close to birth/just after birth

(i)

Functions of the human ear

1. For hearing
2. For balancing

(ii)

The structures in the ear that is responsible for hearing

1. Cochlea
2. Auditory nerve
3. Pinna
4. Eardrum
5. Ear ossicles
6. Auditory canal

The structure in the ear that is responsible for balancing

Semi-circular canals

(i)

Differences between red blood cells and white blood cells

(ii)

Expected changes that will occur in the composition of the blood leaving a muscle of a person soon after a period of vigorous activity

1. There is increase in carbon dioxide
2. There is decrease in oxygen
3. There is decrease in glucose

(i)

Difference between a saturated hydrocarbon and an unsaturated hydrocarbon

Saturated hydrocarbons are hydrocarbons/compounds which have molecules containing only single covalent bonds whereas/while unsaturated hydrocarbons are hydrocarbons/compounds with double or triple bonds between carbon atoms.

(ii)

(i)

Seed dispersal is the spreading of seeds away from the parent plant.

(ii)

Ways in which seed dispersal is important

1. It prevents overcrowding of seedlings
2. It prevents competition for resources between seedlings and parent plant (or between seedlings)
3. It allows plants to colonize new habitats/areas/lands
4. It minimizes epidemic diseases among seedlings
5. It prevents total destruction of plants by natural disasters (or it prevents plants from extinction)
6. It ensures that few plants are eaten by predators
7. It results in diversity of vegetation in any given location (or it results in availability of a plant species in many widely dispersed areas)

(i)

Potential energy is the energy possessed by a body due to its position above a reference point (or the ground or relative to others).

(ii)

Potential Energy (P.E) = Mass (m) x Acceleration due to gravity (g) x Height (h)

Mass = 400 g = $\frac{400}{1000}$ kg = 0.4 kg

Height = 120 cm = $\frac{120}{100}$ m = 1.2 m

Acceleration due to gravity = 10 ms^-2

Potential Energy = 0.4 kg x 10 ms^-2 x 1.2 m

Potential Energy = 4.8 J

(i)

Examples of inorganic fertilizers

1. NPK
2. Sulphate of ammonia
3. Urea
4. Muriate of potash/suphate of potash
5. Potassium nitrate
6. Rock phosphate
7. Sodium nitrate
8. Potassium chloride
9. Calcium nitrate
10. Ammonium nitrate

(ii)

Examples of organic fertilizers

1. Compost
2. Farmyard manure
3. Pig dung
4. Cow dung
5. Green manure
6. Fish manure
7. Poultry droppings
8. Sewage
9. Guano

(i)

Examples of endoparasites of cattle

1. Tapeworm
2. Liver Flukes
3. Round worm
4. Pin Worm

(ii)

Methods of controlling pest of cattle

1. Ensure proper sanitation in the farmhouse
2. Practice dipping on farm animals using appropriate pesticides
3. Ensure proper stocking density
4. Isolate / cull infested animal
5. Practice rotational grazing
6. Practice controlled burning of pasture
7. Dust with recommended pesticides

(i)

Formula mass of a compound is the sum of the atomic masses of constituent atoms in a compound.

(ii)

(i)

Ways by which humans could be protected from harmful effects of radioactivity

1. Minimize time of exposure
2. Move far away from source of radiation
3. By using protective clothing

(ii)

Uses of radioisotopes

1. For food preservation
2. For insect/pest Control
3. To improve crop
4. For equipment sterilization
5. Use as a fuel in nuclear reactor
6. Use to establish ages of various objects
7. Production of atomic bombs
8. Production of electricity