KUULCHAT
SCIENCE MOCK

OBJECTIVE TEST

1.

The process whereby soil is formed by the breakdown of rocks is called

A.

composting.

B.

erosion.

C.

leaching.

D.

weathering.

Answer: D

2.

What structure links the mouth with the stomach? The

A.

duodenum

B.

oesophagus

C.

Ileum

D.

trachea

E.
colon

Answer: B

3.

Heat is transferred along an iron bar by

A.

absorption.

B.

conduction.

C.

convection.

D.

radiation.

Answer: B

4.

Millon's reagent is used to test for

A.

carbohydrates.

B.

fats.

C.

proteins.

D.

vitamins.

Answer: C

5.

Which of the following activities of man causes both air and water pollution?

A.

Afforestation

B.

Construction of houses

C.

Construction of roads

D.

Deforestation

E.

Industrialization

Answer: E

6.

A hunter experiences a backward force upon firing a gun. Which of the Newton's laws of motion is demonstrated in the situation?

A.

First law

B.

Second law

C.

Third law

D.

Law of inertia

Answer: C

Newton's third law states that for every action (force) in nature there is an equal and opposite reaction. If object A exerts a force on object B, object B also exerts an equal and opposite force on object A.

When a bullet is fired from a gun, the gun exerts a force on the bullet in the forward direction. This is the action force. The bullet also exerts an equal force on the gun in the backward direction. This is the reaction force.

7.

The end-product of protein digestion is

A.

amino acid.

B.

glycerol.

C.

glycogen.

D.

peptide.

Answer: A

8.

Urinating in rivers is a common manner of spreading diseases such as

A.

cholera

B.

bilharzia

C.

malaria

D.

measles

E.
Typhoid

Answer: B

9.

The figure below shows a simple electric circuit.

Use it to answer the question below.

The purpose of the component labelled IV is to

A.

supply energy to the circuit.

B.

measure the voltage of the battery.

C.

prevent too much current from flowing.

D.

close the circuit.

Answer: C

10.

An animal feed made up of high fibre is most likely to contain

A.

maize grain.

B.

silage.

C.

soybean.

D.

wheat grain.

Answer: B

11.

The number of oxygen atoms present in three molecules of carbon dioxide is

A.

3.

B.

4.

C.

5.

D.

6.

Answer: D

12.

The part of the flower that contains nectar is called

A.

anther.

B.

petal.

C.

ovary.

D.

sepal.

Answer: A

13.

The earth moves completely round the sun once in every

A.

1 day.

B.

28 days.

C.

30 days.

D.

365 days.

Answer: D

14.

Which of the following ions is formed by the loss of 2 electrons?

A.

Ca2+

B.

S2-

C.

K+

D.

F-

Answer: A

Cations are positively charged and they lose electrons. The number of positive charges in the superscript indicates the number of electrons lost. Calcium (Ca) has 2 positive charges which indicates the lost of 2 electrons.

15.

A torchlight derives its energy from

A.

petrol

B.

kerosene

C.

a magnet

D.

gas oil

E.
a dry cell

Answer: E

16.

A boy exerts a force of 40.0 N to lift a load into a vehicle. If the work done is 80.0 J, calculate the distance through which the load is lifted.

A.

0.5 m

B.

2.0 m

C.

40.0 m

D.

120.0 m

E.

3200.0 m

Answer: B

Work done = Force x Distance

Distance = Work done Force

Work done = 80.0 J

Force = 40.0 N

Distance = 80.0 J 40.0 N = 2 m

17.

The work done when a force moves a body through a distance of 12 m is 720 J. The force applied is

A.

8640 N

B.

732 N

C.

708 N

D.

60 N

Answer: D

Work done = Force x Distance

Work done = 720 J
Distance = 12 m

720 = Force x 12

Divide both sides by 12

Force = 720 12 = 60 N

18.

Steel is an alloy of
A.
Iron and Carbon
B.
Zinc and Copper
C.
Tin and Copper
D.
Iron and Zinc
E.
Carbon and Zinc

Answer: A

19.

Gases enter and leave the leaf of a plant through the

A.

mesophyll cells.

B.

stomata.

C.

pith.

D.

palisade cells.

Answer: B

20.

Which of the following is not a communicable disease?

A.

smallpox

B.

chicken pox

C.

influenza

D.

pneumonia

E.
Tuberculosis

Answer: D

21.

Which of the following parasites is a plant?

A.

Aphid

B.

Dobber

C.

Flea

D.

Jigger

Answer: B

DODDER PARASITE

22.

Which of the following liquids would turn blue litmus paper red?

A.

Vinegar

B.

Water

C.

Ammonia solution

D.

Bicarbonate solution

Answer: A

23.

The property of metals which makes them to be easily drawn into thin wires is known as

A.

conductivity.

B.

ductility.

C.

malleability.

D.

resistivity.

Answer: B

24.

Pluto is the darkest planet because it

A.

is larger than the sun

B.

is the largest planet

C.

is beyond the reach of the sun’s rays

D.

is smaller than the sun

E.
falls in the penumbra region of an eclipse

Answer: C

25.

Which of the following types of soil is good for plant growth?

A.

Clay

B.

Course sand

C.

Fine sand

D.

Loam

E.
Silt

Answer: D

26.

What is the systematic name of the compound CO?

A.

Carbon (I) oxide

B.

Carbon (II) oxide

C.

Carbon dioxide

D.

Carbon (IV) oxide

Answer: B

CO (carbon mono oxide) systematic name is carbon (II) oxide

27.

A solar cell produces electrical energy from

A.

electromagnets

B.

heat

C.

light

D.

sound

Answer: C

28.

Which of the following parasites lives in the blood of humans?

A.

Louse

B.

Plasmodium

C.

Tapeworm

D.

Tick

Answer: B

Plasmodium is the parasite that cause malaria in humans.

29.

Weeds on a school farm could be controlled by

A.

handpicking

B.

mowing

C.

ploughing

D.

tilling

Answer: A

30.

The structure which enables a fish to breate in water is

A.

buccal cavity

B.

gills

C.

swim bladder

D.

lungs

Answer: B

Fish gills are organs that allow fish to breathe underwater. Most fish exchange gases like oxygen and carbon dioxide using gills that are protected under gill covers on both sides of the pharynx. Gills are tissues that are like short threads, protein structures called filaments

31.

An example of intensive system of poultry keeping is the

A.

deep litter system.

B.

fold unit system.

C.

free range system.

D.

free-running system.

Answer: A

32.

The gaps left between railway lines is to allow for

A.

expansion.

B.

cooling.

C.

maintenance.

D.

easy stopping.

E.

gear changing.

Answer: A

33.

A fertilized ovule results in the formation of

A.

an ovary

B.

a style

C.

a pistil

D.

a stigma

E.
an embryo

Answer: E

34.

Which of the following farm animals is/are housed in a hutch?

I. Goats
II. Pigs
III. Rabbits

A.

I only

B.

III only

C.

I and II only

D.

II and III only

Answer: B

35.

Which of the following substances causes acid rain when released into the atmosphere?

A.

Carbon dioxide

B.

Water vapour

C.

Sulphur dioxide

D.

cement dust

Answer: C

Sulfur dioxide reacts with water to form sulfurous acid (H2SO3) as the product.

S02(g) + H2O(l) → H2SO3(l)

36.

Which of the following processes involve a change in the state of matter from liquid to solid?

A.

Evaporation

B.

Freezing

C.

Melting

D.

sublimation

Answer: B

37.

A fruit adapted for dispersal by wind is likely to be

A.

succulent

B.

brightly coloured

C.

hooked

D.

sticky

E.
hairy

Answer: E

38.

Which of the following is a structure in the ear?

A.

Cornea

B.

Cochlea

C.

Iris

D.

Retina

E.
Trachea

Answer: B

39.

An example of a disease transmitted through air is

A.

bilharzia.

B.

cholera.

C.

measles.

D.

typhoid.

Answer: C

40.

Which of the following substances is used to purify water for town supply?

A.

Alcohol

B.

Carbon dioxide

C.

Chlorine

D.

Nitrogen

E.
Sulphur

Answer: C

THEORY QUESTIONS

1.

a)

i)

What are stars?

ii)

Arrange in order, starting from the sun, the first four planets in the solar system.

b)

State

i)

two differences between plants and animals;

ii)

two similarities between plants and animals.

c)

Explain each of the following farming systems:

i)

pastoral farming;

ii)

ecological farming.

d)

State the properties of water in terms of

i)

odour,

ii)

taste,

iii)

effect on litmus.

a)

i)

Stars are natural heavenly bodies/natural bodies in space that burn to produce heat and light.

OR

Stars are glowing balls of hot gas in space.

ii)

Arrangement in order from the sun to the first four planets in the solar system

1. Mercury
2. Venus
3. Earth
4. Mars

Note: The following is an acronym to remember the nine planets in order

My (Mercury) Very (Venus) Easy (Earth) Method (Mars) Just (Jupiter) Speeds (Saturn) Up (Uranus) Nothing (Neptune)

b)

i)

Differences between plants and animals

Plants Animals
Respond slowly to stimuli Respond quickly to stimuli
Autotrophic/manufacture their own food from simple inorganic materials Heterotrophic/do not manufacture their own food
Level of coordination is less than in animals due to absence of complex nervous system Have complex nervous system which is responsible for their ability to exhibit complex behaviour
Do not move from place to place Move freely from place to place
Cells possess large and permanent vacuoles/Large vacuole Cells possess small and temporary vacuoles
Cells possess chloroplasts that contain chlorophyll Cells have no chloroplasts
Excess carbohydrates are stored as starch Excess carbohydrates in cells are stored as glycogen
Take in carbon dioxide to prepare food and release oxygen into the atmosphere Take in oxygen and release carbon dioxide into the atmosphere
Cells have cell wall Cells have no cell wall
Have cellulose Have no cellulose
Growth takes place at definite regions/growth is localized Growth takes place in all body parts
Waste products are stored and used by plants Animal by-products are toxic/poisonous to cell and must be excreted

ii)

Similarities between plants and animals

1. They are made up of cells
2. They feed
3. They respire
4. They move
5. They are sensitive to stimuli
6. They reproduce
7. They excrete
8. They grow

c)

i)

Pastoral farming is a type of farming system in which the farmer keeps only animals and moves from place to place with them in search of food and water.

ii)

Ecological farming is a type of farming system in which chemicals and heavy machinery are not used in order to protect the environment.

d)

i)

Properties of water in terms of odour

Water is odourless

ii)

Properties of water in terms of taste

Water is tasteless

iii)

Properties of water in terms of effect on litmus

Water is neutral to litmus

OR

Water does not change blue or red litmus paper

OR

Water has no effect on litmus paper

2.

a)

The diagrams below are illustrations of an experiment in the laboratory using a piece of stone, a cork of mass 4.0 g and other necessary materials.

The initial volume of water in A was read and noted. A string was attached to a piece of stone and the stone lowered gently into the water as shown in B. The volume was again read and noted. Finally, the cork of mass 4.0 g was attached to the stone and both materials lowered gently into the water as shown in C. The volume was read and noted.

i)

Why did the level of the water rise when the stone was lowered gently into it as shown in diagram B.

ii)

Why was it necessary to attach the stone to the cork before lowering it gently into the water as shown in diagram C?

iii)

What would have happened if the cork alone were lowered gently into the water?

iv)

What is the volume of the

α)

stone?

β)

cork?

v)

Calculate the density of the cork.

vi)

Why were the materials lowered gently in to the water?

b)

A salt solution was prepared in the laboratory using the set of apparatus illustrated below. Study the illustrations carefully and used them to answer the question that follow.

i)

Name each of the apparatus labelled I, II, III, IV and V.

ii)

State one function of each of the apparatus labelled I, II, III, IV and V.

c)

The diagram below is an illustration of the external features of a flowering plant.

Study it carefully and use it to answer the questions that follow.

i)

Name the parts labelled I, II, III, IV, V and VI.

ii)

State one function of each of the parts labelled I, II, III, V and VI.

iii)

State the two main parts of a flowering plant.

d)

The diagram below is an illustration of a small farm animal.

i)

Identify the animal.

ii)

Name each of the parts of the animal labelled I, II, III, IV, V and VI.

iii)

Name the structure in which the animal is kept.

iv)

Mention three breeds of the animal.

v)

State two management practices to be adopted in order to control diseases and pests in the rearing of the animal.

a)

i)

The stone displayed water

OR

The stone occupied space

OR

The volume of the stone was added to the water

ii)

The cork would float

OR

The stone acts as a sinker

iii)

The cork will move up again

OR

The cork will float

iv)

Volume = Final Volume - Initial Volume

α)

Volume of stone = 38 cm3 - 20 cm3 = 18 cm3

β)

Volume of cork = 40 cm3 - 38 cm3 = 2 cm3

v)

Density = Mass Volume

Density of cork = Mass of cork Volume of cork

Mass of cork = 4 g

Volume of cork = 2 cm3

Density of cork = 4 g 2 cm3

Density of cork = 2 gcm-3

vi)

To avoid splashing/spilling of water

b)

i)

I → Volumetric flask
II → Beaker
III → Funnel
IV → Stirring rod/Stirrer
V → Wash bottle

ii)

I → Used to prepare standard solution or prepare solution of known/given volume

II → Used to dissolve the solute/It could also be used to hold solution.

III → Transfer liquid/solution into the flask

IV → To stir or mix the solution

V → The water it contains is used to top solutions up to required level without exceeding the level/It can be used to wash solution stuck to containers for effective titration experiments

c)

i)

I → Terminal bud II → Flower III → Leaf IV → Leaf stalk/petiole/node V → Stem VI → Root

ii)

Functions of I (Terminal bud)

1. Protects the growing regions
2. Develops into flower

Functions of II (Flower)

1. For reproduction
2. Fruit formation
3. For pollination

Functions of III (Leaf)

1. For photosynthesis/absorption of sunlight
2. For transpiration
3. For exchange of gases between the atmosphere and the plant

Functions of V (Stem)

1. Holds leaves/flowers to perform their functions
2. Transports/conducts water to parts of plant
3. For Storage of food

Functions of VI (Root)

1. Absorption of nutrients/water from the soil
2. Holds/Anchors plant firmly in the soil
3. Stores excess food in some plants

iii)

Main parts of a flowering plant

Shoot (system)
Root (system)

d)

i)

Rabbit

ii)

I → Ear/Pinna
II → Cleft lip
III → Belly
IV → Hind limb
V → Tail
VI → Rump

iii)

Hutch

iv)

Breeds of rabbit

1. Dutch
2. Chinchilla
3 Rose
4. English
5. Beveren
6. Belgian
7. New Zealand
8. Chin Ginganta
9. Flenish Giant
10. Polish
11. New Zealand Red
12. Angora
13. California White
14. Florida White
15. Havana
16. Lilac
17. Lop
18. Rex
19. Spanish (Giant)
20. Continental Giant
21. Cinnamon
22. Silver

v)

Management practices to be adopted in order to control diseases and pests in the rearing of rabbit

1. Regular vertinary services
2. Provide good drinking water
3. The hutch should be cleaned regularly
4. The feeder should be washed
5. Disinfectant should be used
6. Dry feed should be given to the animal
7. Recommended pesticides should be used to control pests
8. Separate/isolate sick animals from healthy ones

3.

a)

In an experiment to demonstrate a property of light, three cardboards, A, B, and C with holes in their centres are arranged in a straight line between a lighted bulb and an observer as shown in the illustration below.

Study the illustration carefully and use it to answer the question that follow:

i)

What would the observer see from the position shown?

ii)

What would the observer see when cardboard B is slightly displaced from the line?

iii)

Explain the observation made in (a) (ii) above.

iv)

What would be observed when the cardboard B is brought back to its original position?

v)

What property of light is being demonstrated in this experiment?

vi)

Mention

α)

two natural occurrences that could be explained by the property of light demonstrated.

β)

one device that works on the property of light demonstrated.

b)

The diagrams below are illustrations of hazards symbols found in everyday life.

Study them carefully and use them to answer the questions that follow:

i)

What does each symbol A, B, C and D represent?

ii)

Name one substance each that is associated with each of the symbols A, B and C.

iii)

Name one place where the symbols D can be found.

iv)

State two advantages of hazard symbols.

c)

The diagrams below are illustrations of the different types of teeth in humans.

Study them carefully and use them to answer the questions that follow:

i)

Identify each type of teeth labelled A, B and C.

ii)

Describe the shape of each of the teeth labeled A, B and C.

iii)

State one function of each of the teeth labeled A, B and C.

iv)

Name the parts of the teeth labeled I and II.

d)

The diagrams below are illustrations of some farm tools.

Study them carefully and use them to answer the questions that follow:

i)

Identify each of the following labeled A, B, C, D and E.

ii)

Mention one use of each of the tools labeled A, B, C, D and E.

a)

i)

Light/lighted bulb/light ray(s)

ii)

No light would be seen/part of the cardboard B would be seen.

iii)

Light travels in a straight line and because cardboard B is shifted out of the straight line, the light is not seen again.

iv)

The lighted bulb/light/light rays(s).

v)

Linear/rectilinear propagation of light/light travels in a straight line.

vi)

α)

Natural occurrences that could be explained by the property of light demonstrated

1. Eclipse
2. Shadow

β)

Devices that works on the property of light demonstrated

1. Pinhole camera
2. Periscope
3. Touch light
4. Hunter's lamp
5. Parabolic mirror
6. Car lamps
7. Optical fibre
8. Laser
9. Binoculars

b)

i)

A → Highly inflamable/flammable/catches fire easily
B → Harmful/irritant
C → toxic/poison/poisonous
D → Danger

ii)

Highly inflammable substances (A)

1. Petrol
2. Kerosene
3. Gas/Liquefied Petroleum Gas (LPG)
4. Sodium
5. Ethanol
6. Thinner
7. Turpentine
8. Carbon disulphide

Harmful/irritant substances (B)

1. Sodium hydroxide
2. Mineral acids/Phenol/H2SO4/HNO3
3. Aluminum sulphate
4. Calcium Hydroxide

Toxic/poisonous substances (C)

1. Cyanide
2. DDT
3. Mercury
4. Lead compounds

iii)

Places where the symbols D(Danger) can be found

1. Highways/roads
2. High voltage equipment
3. Laboratories
4. Construction sites

iv)

Advantages of hazard symbols

1. They warn us of danager so that we do not harm ourselves
2. They prevent accidents or damage of properties

c)

i)

A → Incisor B → Premolar/molar/cheek tooth C → Canine

ii)

Shape of A(Incisor)

Is chisel shaped

Shape of B(Premolar)

Has flat and broad surface with cusps/ridges/projections

Shape of C(Canine)

(Bluntly) pointed/conical

iii)

Function of A(Incisor)

For cuttin/biting

Function of B(Premolar)

For grinding/chewing/crushing

Function of C(Canine)

For tearing

iv)

I → Enamel/Crown
II → Root

d)

i)

A → Garden fork/digging fork/foot fork
B → Spade
C → Hand trowel
D → Hand fork
E → Watering can

ii)

Uses of A(Garden fork)

1. Turning/loosening soil
2. Stirring soil

Uses of B(Spade)

1. Turning soil
2. Collection of soil
3. Levelling of soil surface
4. Mixing of animal feeds

Uses of C(Hand trowel)

1. Transplanting seedlings
2. Earthing up vegetable crops
3. Heaping soil around vegetable crops
4. Spreading manure

Uses of D(Hand fork)

Stirring/Loosening soil in nursery beds/vegetable beds

Uses of E(Watering can)

Watering

4.

(a)

Distinguish between the following terms:

(i)

Physical change and chemical change

(ii)

Solution and suspension

(b)

Classify the following as either a physical or chemical change

(i)

Common salt in water

(ii)

Burning of charcoal

(iii)

Melting of ice

(iv)

Hydrochloric acid in sodium hydroxide solution

(c)

(i)

What is a parasite?

(ii)

Give two examples of parasites and their hosts.

(d)

Give the chemical symbols of the following elements

(i)

Oxygen

(ii)

Chlorine

(iii)

Aluminium

(iv)

Calcium

(e)

(i)

Explain the term self-pollination

(ii)

Name four agents of pollination

(iii)

State the function of the brightly coloured petals in insect pollination

(a)

(i)

Differences between a physical change and a chemical change

Physical Change Chemical Change
No new substance is formed New substance is formed
It is easily reversible It is irreversible
It is not accompanied by great heat change It is accompanied by great heat change
There is no change in mass There is change in mass
Individual components retain their properties Individual components lose their properties

(ii)

Difference between solution and suspension

A solution is a uniform/homogeneous mixture of a solute and a solvent where the solute completely disappear from sight in the solvent (liquid) whiles a suspension is a mixture of particles of an insoluble substance and a liquid whereby the particles of the substance float in the liquid. The small particles settle at the bottom of the container when it is left undisturbed.

(b)

(i)

Common salt in water → physical change

(ii)

Burning of charcoal → chemical change

(iii)

Melting of ice → physical change

(iv)

Hydrochloric acid in sodium hydroxide solution → chemical change

(c)

(i)

Parasite is any organism/living thing that lives in or on another organism/living thing called the host for its food and by so doing causes harm to the host.

(ii)

Examples of parasites and their hosts

Parasite Host
Lice Man
Tick Dog
Plasmodium Man
Mistletoe Cocoa/cola
Dodder Milk bush/cashew plant
Capsids Cocoa plant
Tapeworm Cow/pig/man

(d)

Chemical symbols

(i)

Oxygen → O

(ii)

Chlorine → Cl

(iii)

Aluminium → Al

(iv)

Calcium → Ca

(e)

(i)

Self-pollination is the transfer of pollen grains from the anther of a flower to the stigma of the same flower or to the stigma of another flower of the same plant.

(ii)

Agents of pollination

1. Insects
2. Water/Rain
3. Animal/Man/Birds/Bats
4. Wind

(iii)

Function of the brightly coloured petals in insect pollination

They produce nectar which attracts insects to the plant.

5.

a)

What is an electrostatic force?

b)

i)

State the unit of

α)

force

β)

work

ii)

A body of mass 80 kg is lifted vertically through a distance of 5.0 m.

Calculate the work done on the body.

[g = 10 ms-2]

c)

Describe briefly how a mixture of common salt and powdered sulphur could be separated.

d)

State three characteristics each of

i)

an insect pollinated flower

ii)

a wind pollinated flower

a)

An electrostatic force is the force that exists between electric charges that are stationary on charged bodies.

b)

i)

α)

The unit of force is newton (N)

β)

The unit of work is joule/joules(J)

ii)

Work done = Force x Distance

Force = Mass x Acceleration due to gravity (g)

Mass = 80 kg
g = 10 ms-2

Force = 80 kg x 10 ms-2 = 800 N

Distance = 5 m

Work done = 800 N x 5 m = 4000 J

c)

How a mixture of common salt and powdered sulphur could be separated

1. Add water to the mixture and stir to dissolve the salt
2. Filter the resulting mixture
3. Sulphur is left on the filter paper and is dried
4. Heat the salt solution in an evaporating dish to obtain the salt

d)

i)

Characteristics of an insect pollinated flower

1. Petals are large
2. Petals are brightly coloured
3. The flower is usually scented
4. The flower has nectar
5. Stigma is inside the flower
6. Stigma is compact and sticky
7. Pollen grains produced per anther are few
8. Pollen grains are sticky, large, rough and heavy
9. Filaments are short and stout

ii)

Characteristics of a wind pollinated flower

1. Have less brightly coloured petals/petals are dull in colour
2. Petals are small in sizes and not easily seen or absent
3. The flower lacks nectar
4. The flower is not scented
5. Large amount of pollen grains are produced per anther
6. Have feathery/hairy stigma
7. Stigma hangs down to be able to catch pollen grains floating in the air
8. Pollen grains are small, light or dry and smooth
9. Filaments are long and flexible

6.

(a)

In an experiment, as in the set-up above, two glass containers A and B of different sizes are joined together with a tube and clipped.

Water is poured into container A to a height of 30 cm and a red liquid is poured into B to a height of 10 cm. The clip is then removed so that the liquids join together.

(i)

State two observations that will be made immediately the clip is removed.

(ii)

Explain the observations in (i).

(iii)

What two observations will be made after a long time? Explain.

(b)

The set-up below is used in the preparation of ammonia gas in the laboratory

Study it and answer the questions that follow.

(i)

Name the parts labelled a, b and c

(ii)

What is the meaning of the arrow sign d?

(iii)

What is the function of the calcium oxide?

(iv)

Why has c been tilted downwards?

(v)

State the method by which the gas is collected.

(vi)

How will you test for the gas?

(vii)

Give the names and the chemical formulae of the compounds that form the content of c.

(c)

In an experiment, a leaf that is partly green and partly yellow is plucked from a tree and the leaf is

I boiled for a minute,

II dipped in warm alcohol,

III washed in cold water,

IV dipped in iodine solution.

One part of the leaf turns blue-black after the dipping in iodine solution while the other part remains unchanged.

(i)

Explain why each of the processes I, II and III

(ii)

Which part of the leaf turns blue-black? Explain.

(iii)

Why does the other part of the leaf not change colour?

(iv)

What conclusion can you draw from the experiment?

(a)

(i)

1. The level of water decreases and the level of the red liquid rises
2. Red liquid moves/diffuses into the water

(ii)

1. Water is at a higher potential/level/pressure so it moves in the direction of lower potential/level/pressure
2. Molecules of red liquid at a higher concentration moves towards region of lower concentration/molecules of red liquid diffuse into the water

(iii)

1. The level of the liquids will be the same/motion of the liquids stop (greater than 10 cm but lower than 30 cm) because the same pressure will be exerted by the liquids in A and B
2. The colour of the liquid in A and B will be uniform/same (pale/light red) because the concentration will be the same

(b)

(i)

a → ammonia gas
b → gas jar
c → round bottomed flask

(ii)

The meaning of the arrow sign d is heating

(iii)

The calcium oxide dries the gas produced

(iv)

c is tilted downwards to prevent condensed water from falling back into the hot flask/to cause cracking

(v)

Upward delivery/downward displacement of air

(vi)

Test for the ammonia gas

Damp/moist red litmus paper turns blue in the presence of the (ammonia) gas

OR

Gas produces fumes with HCl vapour/concentrated hydrochloric acid

OR

Gas has pungent/choky/urinal smell

(vii)

1. Calcium hydroxide (Ca(OH)2)/Sodium hydroxide (NaOH)

2. Ammonium chloride/Ammonium salt (NH4Cl)

(c)

(i)

I → to kill cells/stop photosynthetic process
II → to remove green pigment/decolourized
III → to wash off the alcohol/to soften the leaf

(ii)

The green part turns blue-black because photosynthesis took place in the green part to produce starch

(iii)

The other (yellow) part of the leaf not change colour because it does not contain chlorophyll/green pigment which will trap sunlight for photosynthesis to occur

(iv)

Presence of chlorophyll/green pigment in leaf is required/necessary for photosynthesis/production of starch to take place/occur