(i)

A → Thermometer
B → Micrometer screw gauge
C → Volumetric or flat bottomed flask
D → Tripod stand
E → Test tube holder
F → (A pair of) tongs
G → Vernier caliper
H → Pipette
I → Bunsen burner

(ii)

I → bulb
II → mercury
III → bore or capillary
IV → glass wall or stem

(iii)

A (Thermometer) is used to measure temperature or degree of hotness or coldness of a substance.

B (Micrometer screw gauge) is used to measure the thickness or diameter of an object.

C (Flat bottomed flask) is used for measuring or holding (250 ml) of liquid. For preparation of a standard solution or for measuring 250 ml or a known volume of a solution.

D (Tripod stand) is used to support flasks and beakers.

E (Test tube holder) is used for holding test tube during heating.

F (Tongs) is used to hold (hot) objects.

G (Vernier caliper) is used to measure the distance between two opposite sides of a surface.

H (Pipette) is used for drawing solutions or liquids from one container into another or for drawing specific volume of liquids or volumes of liquid.

I (Bunsen burner) is used for heating substances.

(iv)

How to use A (Thermometer)

1. Suspend bulb in medium whose temperature is to be determined
2. Allow few minutes for mercury to expand or contract to maximum or minimum level
3. Read off mercury level (against calibrations to give temperature of medium)

How to use B (Micrometer screw gauge)

1. Place the object in the gauge or anvil and spindle or jaws
2. Use the ratchet or thimble to tighten the object (till the ratchet begins to rattle)
3. Add the readings on both the thimble and the sleeve to give thickness of the object

How to use F (Tongs)

1. The thumb is placed in one of the cavities or holes of the handle and another finger placed in the other cavity
2. To open up the device
3. The open end is used to hold the (hot) object

How to use G (Vernier caliper)

1. Object is placed in the jaw
2. The knob is used to slide the jaws to hold the object firmly and the reading is taken through the window on the scale

How to use H (Pipette)

1. The pointer end of the pipette is immersed in the solution
2. The mouth is put at the blunt or opposite end and air sucked from it
3. The liquid level is allowed to rise above the mark and the thumb used to seal the end where the mouth was put
4. The thumb is partially removed to drain some solution or liquid to the mark
5. The thumb is completely removed to allow solution or liquid drain into the appropriate container

(i)

A → Flower
B → Fruit

(ii)

(iii)

Structure B (fruit) develops from structure A (flower).

(iv)

Explosive mechanism

(v)

Plants which produces structures similar to B (fruit)

1. Flamboyant
2. Caesalpinea or pride of Barbados
3. Crotalaria
4. Bean
5. Squirting cucumber
6. Cowpea
7. Balsam

(i)

A → Boerhaavia (sp) or pig weed; Desmodium (sp)
B → Tridax (sp); Silk cotton (sp); Tecoma (sp)
C → Acacia (sp); Cassia (sp); Pride of Barbados or Caesalpinea (sp); Crotalaria (sp);Beans or Cowpea

(ii)

A → Animal or human
B → Wind
C → self or explosive mechanism

(iii)

Fruit A

1. Has sticky hairs which get attached to fur or skin of animal or clothing of human
2. As the animal or human moves along, the fruit may be dislodged and drop at a different location

Fruit B

Has hairs or is light which enable the fruit to float in the air and transported to a different locality.

Fruit C

1. Has margin which is capable of splitting when it dries up or unequal drying of the fruit coat
2. Tension set up in the fruit while it dries or twisting of the pericap
3. Causes seeds to be thrown out as it splits open

(iv)

Importance of dispersal of seeds

1. It prevents overcrowding of plants or reduces competition for light and soil nutrients among seedlings
2. It enables plant to grow in new places
3. It reduces the spread of epidemic diseases among crowded seedlings
4. It enhances the survival of the species
5. It prevents intense feeding by herbivorous animal

(i)

A → dicotyledonous seed
B → monocotyledonous seed

(ii)

I → endosperm
II → plumule
III → testa
IV → plumule

(iii)

Structural differences between monocotyledonous and dicotyledonous seeds

(iv)

Observation when drop of iodine is added to I (endosperm)

It will turn blue black.

(v)

Why iodine turns blue black when added to I (endosperm)

This is because I (endosperm) contains starch

(i)

(ii)

Differences between an element and a compound

(iv)

(v)

(i)

Importance of rainfall to the life cycle of crops

1. For seed germination
2. For cooling plants or soil
3. For dissolving mineral salts for absorption

(ii)

Importance of temperature to the life of cycle crops

1. For germination of seeds
2. Drying of seeds

(iii)

Importance of sunshine to the life cycle of crops

1. For photosynthesis
2. Drying of seeds

(iv)

Importance of wind to the life cycle of crops

1. For pollination
2. For dispersal of seeds

(i)

(ii)

Functions of parts of an eye

Sclera: It is the outer covering, a protective tough white layer called the sclera (white part of the eye).

Cornea: The front transparent part of the sclera is called the cornea. Light enters the eye through the cornea.

Iris: A dark muscular tissue and ring-like structure behind the cornea is known as the iris. The colour of the iris actually indicates the colour of the eye. The iris also helps regulate or adjust exposure by adjusting the iris.

Pupil: A small opening in the iris is known as a pupil. Its size is controlled with the help of iris. It controls the amount of light that enters the eye.

Lens: Behind the pupil, there is a transparent structure called a lens. By the action of ciliary muscles, it changes its shape to focus light on the retina. It becomes thinner to focus on distant objects and becomes thicker to focus on the nearby objects.

Retina: It is a light-sensitive layer that consists of numerous nerve cells. It converts images formed by the lens into electrical impulses. These electrical impulses are then transmitted to the brain through optic nerves.

Optic nerves: Optic nerves are of two types. These include cones and rods.
1. Cones: Cones are the nerve cells that are more sensitive to bright light. They help in detailed central and colour vision.
2. Rods: Rods are the optic nerve cells that are more sensitive to dim lights. They help in peripheral vision.

(iii)

Defects of the eye

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

(iv)

Corrections of defects of the eye

Long sightedness: Wearing converging or convex lens

Short sightedness: Wearing diverging or concave lens

Astigmatism: Medical treatment or use of special lenses for astigmatism

(i)

(ii)

Kinetic energy = mass x $\frac{{\mathrm{Velocity}}^2}{2}$

Mass = 10kg
Velocity = 2 ms^-1

Velocity² = Velocity x Velocity

Kinetic energy = mass x $\frac{\mathrm{Velocity\; x\; Velocity}}{2}$

Kinetic energy = 10 x $\frac{\mathrm{2\; x\; 2}}{2}$

Kinetic energy = 10 x 2 = 20 Joules (J)

(iii)

Mechanical advantage = $\frac{\mathrm{Load}}{\mathrm{Effort}}$ = $\frac{\mathrm{3000N}}{\mathrm{150N}}$ = 20

Note: Mechanical advantage does not have units as the unit of the forces cancel each other.

(iv)

Efficiency = $\frac{\mathrm{Work\; Output}}{\mathrm{Work\; Input}}$ x 100%

Work done = Force x Distance

Work output = Output force x Output distance

Work input = Input force x Input distance

Work output = Load x Load distance = 20 x 2 = 40J

Work input = Effort x Effort distance = 25 x 4 = 100 J

Efficiency = $\frac{40}{100}$ x 100% = 40%

(i)

Pressure is the force exerted (normally) on a unit area

OR

Pressure is force per unit area

(ii)

Pressure = $\frac{\mathrm{Force}}{\mathrm{Area}}$

The smaller the area, the greater the pressure.

The greatest pressure will be at the side where the area is smallest

Area of the surface of block = Length x Breadth

The smallest area will be the multiplication of the smallest lengths.

Smallest surface area = 2m x 5m = 10m²

Force = Mass x Acceleration due to gravity.

Mass = 5kg
Acceleration due to gravity = 10 ms^-2
Force = 5kg x 10 ms^-2 = 50N

Greatest pressure = $\frac{50}{10}$ = 5 pascals

Alternatively, you could calculate for the pressure for each of the surfaces and select the greatest pressure.

Side B (5m x 10m) = 50 m²

Side C (2m x 10m) = 20 m²

Pressure for side B = $\frac{50}{50}$ = 1 pascal

Pressure for side C = $\frac{50}{20}$ = 2.5 pascals

Side A (2m x 5m) = 5 pascals

Hence the greatest pressure will be 5 pascals.

(iii)

(i)

Sublimation is the process by whereby solid particles change directly into the gaseous state or phase (when they obtain heat).

(ii)

Substances that can sublime

1. Camphor
2. Naphthalene
3. Iodine
4. Dry ice
5. Solid carbon dioxide or carbon (IV) oxide
6. Ammonium chloride

(iii)

Differences between excretion and egestion

Excretion is the elimination or removal of metabolic waste products from (tissues of) the body while egestion is the elimination of undigested food materials from the alimentary canal.

(iv)

(i)

Water → Compound

(ii)

Iron filings → Element

(iii)

Glass → Compound

(iv)

Milk of magnesia → Mixture

(iii)

Iodine crystals → Element

(i)

Broom → 3rd class

(ii)

Claw hammer → 1st class

(iii)

Fishing rod → 3rd class

(iv)

Secateurs → 1st class

(v)

Bottle top opener → 2nd class

(vi)

Crowbar → 1st class

(vii)

Beam balance → 1st class

(viiI)

Wheelbarrow → 2nd class

(ix)

Sugar tong → 3rd class

(x)

Human fore-arm → 3rd class

(i)

Causes of indigestion in humans

1. Irregular eating times
2. Heavy smoking
3. Over eating
4. Improper chewing of food or eating food too fast
5. Excessive alcohol intake
6. Stress or fatigue or anxiety or emotional trauma
7. Too much caffeine intake
8. Eating of fatty or greasy or spicy foods
9. Constipation
10. Disease condition/Medication
11. Reduced blood flow in the intestine
12. Obesity
13. Sleeping immediately after eating

(ii)

(iii)

(iv)

Reasons why poultry farms should be distanced from residential areas

1. To prevent obnoxious gases (ammonia or CO₂) from entering people's houses
2. To avoid disturbance from noise of poultry
3. To enable fowls to receive enough natural air
4. For the avoidance of dust spread into the pens
5. For the avoidance of transfer of diseases into the pen

(v)

Methods of preserving poultry egg

1. Cold storage or refrigeration or freezing
2. Frozen liquid eggs
3. Egg powder
4. Use of sodium silicate solution
5. Keeping under dry sand
6. Coating egg with mineral oil or vaseline
7. Salt preservation
8. Covering eggs with lime solution
9. Avoid changing the temperature of the egg
10. Avoid washing the eggs

(i)

Mode of dispersal of fruits

(ii)

Feature that adapts fruits for dispersal

Pawpaw: Possession of fleshy mesocarp or it appears attractive.

Silk cotton: Presence of floss or it is light

Pride of Barbados: Unequal drying of pods.

(iii)

Process of seed germination

1. The seed absorbs water and (swells up)
2. The water activates the enzymes within the seed
3. The enzymes break down food stored in the seed
4. The products of the breakdown are transported to the growing regions
5. The young or embryonic shoot or plumule and root or radicle emerges

(i)

Differences between permanent magnet and temporary magnet

(ii)

(iii)

(i)

States of matter

1. Solid
2. Liquid
3. Gas

(ii)

Methods by which one state can be converted to another

1. Evaporation
2. Boiling
3. Melting
4. Freezing
5. Condensation
6. Sublimation

(iii)

How the fish takes in oxygen

1. Water enters the mouth and passes over the gills

2. The blood in the gills absorbs the oxygen dissolved in the water

(iv)

(i)

Force is that which changes a body's state of rest or of uniform motion in a straight line

OR

A force is a pull or a push on an object.

(ii)

Effects of forces on a body

1. start motion
2. change direction
3. accelerate a body
4. decelerate a body
5. stop a moving body
6. change shape

(iii)

Types of forces

1. Force of gravity
2. Magnetic force
3. Frictional force
4. Electrostatic force
5. Force due to tension or elastic force
6. Centripetal force
7. Viscous drag
8. Gravitational force (weight)
9. Centrifugal force

(iv)

Forces when using a catapult

1. Force of gravity
2. Tension or elastic force
3. Frictional force

(v)

1. Tension or elastic force in the rubber band of the catapult pushed the stone down
2. Force of gravity brought down the mango
3. Frictional force between the stone and the mango or between the leather of the catapult and the stone or between the palm and stick of the catapult

(i)

Alcohol and water → Distillation or fractional distillation

(ii)

Salt and water → Distillation or Evaporation and condensation

(iii)

Powdered charcoal and iron filings → Use of magnet

(iv)

Powdered chalk and water & Filtration or decantation

(i)

Photosynthesis is the process by which green plant produces their own food/carbohydrate/glucose/starch using carbon dioxide and water with the presence of sunlight and chlorophyll.

(ii)

Factors necessary for photosynthesis

1. Water (H₂O) or Mineral salts
2. Carbon dioxide (CO₂) or Carbon (IV) oxide
3. Sunlight or light
4. Chlorophyll or green matter in the leaf

(iii)

(i)

(ii)

Pollination is the transfer of pollen from the anther of a flower to the stigma of the same flower or another flower of the same type.

(iii)

(i)

(ii)

Enzyme is a chemical that initiates or speeds up chemical reactions in living organisms

OR

Enzyme is a biological catalyst.

(iii)

Factors that affect the action of enzymes

1. Temperature
2. pH or level of acidity or alkalinity
3. Substance concentration
4. Enzyme concentration or surface area of substance
5. Product concentration
6. Inhibitors or activators

(iv)

Processes from pollination to seed formation

1. Pollen grain absorbs water or germinates
2. Pollen grain develops or grows into a pollen tube
3. The pollen tube grows through the style and down the wall of the ovary carrying two nuclei (or tube nucleus and generate nucleus)
4. The generative nucleus divides to form two male gametes
5. The pollen tube passes through the mycropyle of the ovule into the embryo sac whee the tip dissolves setting free male games
6. One male gamete fuses or unites with the egg nucleus or ovum to form the zygote which develops into the embryo of the future seed
7. However, the other male gamete fuses with the polar nucleus (or endosperm nucleus) and the fertilized ovule becomes a seed

(i)

(ii)

(iii)

Characteristics of an image formed by a plane mirror

The image:

1. has same size as object
2. is virtual
3. is laterally inverted
4. distance equal to the object distance from the mirror
5. is erect or upright

(i)

(ii)

Characteristics of image formed in a pinhole camera

The image is:

1. diminished
2. inverted
3. real

(iii)

Laws of reflection of light

1. The incident ray, the reflected ray and the normal at the point of incidence all lie in the same plane
2. The angle of incidence is equal to the angle of reflection

(iv)