(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)

Single stroke/single touch

(ii)

A → South pole
B → North pole

(iii)

How to test that the bar AB is a magnet

1. The bar suspended horizontally at its midpoint will be in the North-South direction when at rest
2. Suspend AB freely at its midpoint. One pole of a known magnet brought at a time to the ends A and B will show both attraction and repulsion for both ends
3. The bar AB is brought close to a plotting compass. The compass shows deflection
4. Dip the ends A and B of the bar into iron filings. Iron filings will cling to the poles/magnetic substances are attracted by both ends of the bar

(iv)

How to test for the poles of A and B of the bar

1. South pole of a magnet is brought towards end A of the bar and there is repulsion between them
2. A north pole of a magnet is brought towards end B of the bar and there is repulsion between them

(v)

Precautions that should be taken during the magnetization process

1. The magnet should be drawn along the bar AB in only one direction
2. The magnet should be lifted way off the bar AB at the end of each stroke

(vi)

Other methods of magnetization

1. Divided touch/double touch/double stroke
2. Electrical method/electromagnetisation
3. Induction
4. Hammering

(i)

I → Thistle funnel
II → Delivery tube
III → Flat-bottom flask
IV → Gas jar

(ii)

1. Upward delivery
2. Downward displacement (of water)

(iii)

The gas exerts pressure on the water and pushes it down

(iv)

1. Hydrogen
2. Oxygen
3. Carbon dioxide/Carbon (IV) oxide

(i)

Lime water turns milky due to the presence of carbon dioxide in the expired air.

(ii)

Calcium carbonate/CaCo₃/Calcium trioxocarbonate (IV)

(iii)

Ca(OH)₂ + CO₂ → CaCo₃ + H₂O

(iv)

Other substances present in breathed-out air

1. Water vapour/water
2. Nitrogen
3. Rare gases
4. Oxygen (unused)

(v)

To show that carbon dioxide is a by-product of respiration

OR

To show that carbon dioxide is present in expired air/breathed out

(i)

Classes of food

1. Carbohydrates
2. Proteins
3. Fats and oils
4. Vitamins
5. Mineral salts
6. Water

(ii)

Starch → Carbohydrate
Milk → Protein
Margarine → Fat and oil
Sugar → Carbohydrate

(i)

calcium hydroxide → Ca(OH)₂

(ii)

zinc chloride [zinc (II) chloride] → ZnCl₂

(iii)

sodium nitrate [sodium trioxonitrate (V)] → NaNO₃

(iv)

calcium carbonate [calcium trioxocarbonate (IV)] → CaCO₃

(v)

potassium sulphate [potassium tetraoxosulphate (VI)] → K₂SO₄

(i)

Viscosity is defined as the internal force that opposes the movement of liquid molecules.

(ii)

An experiment to compare the viscosities of two liquids A and B

1. Liquid A and B are both poured into two separate identical measuring cylinders to the same level
2. Two identical metal balls are dropped into each of the measuring cylinders and the time taken for each ball to reach the bottom/base of the cylinders of liquids A and B are recorded
3. The liquid in which the metal ball took a longer time to reach the base/bottom of the measuring cylinder is more viscous

(i)

Functions of the skin

1. It excretes waste substances/urea/water/salts/sweat
2. It protects the body from injury
3. It regulates body temperature
4. It gives sense of touch

(ii)

Functions of the lung

1. Gaseous exchange occurs in the lungs/there is intake of oxygen and output of carbon dioxide and water vapour in the lungs
2. Excretion of carbon dioxide and water vapour takes place in the lungs

(iii)

Functions of the kidney

1. It excretes urea/water and salt
2. Urine formation

(iv)

Function of the testis

Sperm production

(i)

Vegetative reproduction is a form of reproduction whereby plants produce young ones from growing parts/buds of the parent plant.

(ii)

Plants which reproduce vegetatively

1. Potato
2. Yam
3. Cocoyam
4. Canna lily
5. Onion
6. Plantain
7. Banana
8. Ginger
9. Pineapple
10. Bryophyllum
11. Sugar cane
12. Cassava
13. Fern
14. Elephant grass
15. Tiger nuts
16. Garlic

(i)

Work is said to be done when the point of application of a force moves an object through a distance in the direction of the force.

OR

Work is said to be done when a force moves a body through a distance in the direction of the force.

OR

Work is the product of force and the distance moved in the direction of the force.

OR

Work = Force x distance moved in the direction of the force

(ii)

Power is the rate of doing work.

OR

Power is the rate at which energy is dissipated

OR

Power = $\frac{\mathrm{Work\; done}}{\mathrm{Time\; taken}}$

(i)

akpeteshie (alcohol) → Distillation

(ii)

common salt → Evaporation/crystallisation

(iii)

tap water → Filtration/sedimentation/coagulation

i)

H₂O → Water/dihydrogen monoxide/hydrogen oxide

ii)

MgO → Magnesium oxide

iii)

CaCO → Calcium oxide

iv)

CaCl₂ → Calcium chloride

i)

Length of a rope → Metre rule/tape measure/ruler/surveyor's tape

ii)

Mass of a stone → Beam balance/chemical balance/top pan balance/electronic balance

iii)

Temperature of a liquid → Thermometer

iv)

Volume of a liquid → Volumetric flask/pipette/graduated cylinder/measuring cylinder/burette/graduated beaker

i)

A satellite is an object that moves around a larger object in space.

OR

A satellite is an artificial body placed in orbit round the earth or another planet.

ii)

Uses of artificial satellite

1. For exploring the planets/moons
2. For scientific research/experimental research/internet
3. To study the universe
4. For communications/broadcasting/telephone call
5. For weather forecast/collecting information on the weather
6. Map making
7. Spying
8. For navigation/satellite for navigation
9. Military purposes

i)

Brass → Copper and zinc

ii)

Steel → Iron and carbon

iii)

Bronze → Copper and tin