(i)

(ii)

Observations in set-up A

The pressure of the water coming out of the lower hole is higher than the one at the top.

Observations in set-up B

The pressures of the water coming out of the holes are the same because they are at the same level.

(iii)

The aim of set-up A is to show that pressure increases with depth in a liquid.

(iv)

The aim of set-up B is to show that pressure at the same point/level in a liquid is the same.

(i)

The volume of solution C = Volume of solution A + Volume of solution B

The volume of solution C = 20 cc + 20 cc

The volume of solution C = 40 cc

(ii)

(iii)

Neutralization reaction

(iv)

Sodium chloride solution/NaCl solution/salt solution/brine

(v)

The water evaporates leaving solid sodium chloride/NaCl

OR

Solid sodium chloride/NaCl/common salt is formed

OR

Solution becomes concentrated

(i)

I → to stop further starch formation/stop photosynthesis process/kill the cells
II → to remove the green pigment/to decolourize the leaf/to remove chlorophyll
III → to soften the leaf

(ii)

Leaf turns blue black

(iii)

Green → colourless/white → blue black

(iv)

The alcohol will catch fire when heated over naked fire.

(vi)

No blue black colour will be seen/colour of iodine will be seen because starch is absent.

(i)

Respiration is the process whereby oxygen is used in living cells to breakdown food leading to the release of energy.

OR

Respiration involves the taking in of oxygen and giving out of carbon dioxide.

OR

Respiration is the breakdown of food to release energy.

(ii)

Differences between photosynthesis and respiration

(i)

Chemicals used in the preparation of carbon dioxide in the laboratory

(Dilute) hydrochloric acid (HCl)/Nitric acid (HNO₃)/Sulfuric Acid/Tetraoxosulphate (VI) acid (H₂SO₄) and Calcium carbonate (marble chips) or any carbonate

(ii)

Test for carbon dioxide in the laboratory

Carbon dioxide is passed through lime water and the lime water turns milky.

(i)

Effects of a force on a body

1. It changes direction of a moving body
2. It increases speed of a body/causes a body to accelerate
3. It decreases speed of a body/causes a body to decelerate
4. It causes a moving body to stop
5. It causes a stationary body to move
6. It causes deformation/changes the shape of a body

(ii)

Work done = Force x Distance

Work done = 250 N x 20 m
Work done = 5000 J

(i)

Differences between a vein and an artery

(ii)

Functions of red blood cells

1. They carry oxygen from lungs to cells
2. They carry carbon dioxide from the cells to lungs

(iii)

Diseases associated with the circulatory system

1. High blood pressure (Hypertension)
2. Low blood pressure (Hypotension)
3. Varicose veins
4. Piles/Haemorrhages
5. Anaemia
6. Leukaemia/blood cancer
7. Arteriosclerosis
8. AIDS
9. Hepatitis
10. Heart failure/Cardiac arrest
11. Sickle cell anaemia
12. Diabetes
13. Stroke
14. Haemophilia
15. Coronary artery disease/Thrombosis
16. Malaria

(i)

(ii)

Physical and chemical changes

For a physical change,
1. The original substance can be obtained by a reverse process
2. There is no new substance formed
3. No change in mass occurs
4. The individual components retain their properties
5. There is no heat involved

For a chemical change,
1. The original substance cannot be obtained by reversing the process
2. New substances are formed
3. Change in mass occurs
4. Individual components lose their properties
5. There is heat involved

(i)

Laws of reflection

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

(ii)

(i)

Vegetative reproduction is the propagation of new individuals of a particular species by means of parts of a parent plant other than (fertilized) seeds.

OR

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

(ii)

Differences between sexual reproduction and vegetative reproduction

(iii)

Advantages of vegetative reproduction

1. Results in species of the same characteristics/features
2. Stores enough food reserve for the offspring
3. Growth is more rapid/fast
4. Only one parent is required to produce the offspring/does not require any agent as in pollination

(i)

(ii)

Solute

(i)

Second class lever

(ii)

I → Effort
II → Load
III → Pivot/Fulcrum

(iii)

Examples of second class levers

1. Wheelbarrow
2. Bottle opener
3. Nutcracker
4. Staplers
5. Nail clippers
6. Doors or gates

(i)

Differences between a parasite and a vector

(ii)

Names of endo-parasites and their hosts

(i)

(ii)

Proton is positively charged
Total positive charge (protons) = +8
Number of protons = number of electrons
Electron is negatively charged
The atom gains 2 extra electrons
Total negative charge (electrons) = -8 + -2 = -10
Net charge of the ion = +8 - 10 = -2

(i)

(ii)

Density = $\frac{\mathrm{Mass}}{\mathrm{Volume}}$

Volume = $\frac{\mathrm{Mass}}{\mathrm{Density}}$

Density = 0.9 g/cm³

Mass = 300 g

Volume = $\frac{300}{0.9}$ cm³

0.9 = $\frac{9}{10}$

Volume = 300 ÷ $\frac{9}{10}$ cm³

Reciprocate the fraction at the right of ÷ and change the ÷ to multiplication (x)

Note: reciprocate means the numerator becomes the denominator and the denominator becomes the numerator.

Volume = 300 x $\frac{10}{9}$ cm³

Volume = $\frac{\mathrm{300\; x\; 10}}{9}$ cm³

Volume = $\frac{3000}{9}$ cm³

Volume = 333.33 cm³