KUULCHAT
SCIENCE MOCK

OBJECTIVE TEST

1.

The washing away of the top soil by running water is called

A.

erosion

B.

rotation

C.

plantation

D.

weathering

E.
irrigation

Answer: A

2.

A metallic saddle was left in a boiling soup. After sometime, the handle became hot.

This is because the particles in the saddle

A.

undergo rapid, random motion,

B.

contain free electrons which are able to transfer heat energy.

C.

are separated by large distances.

D.

circulate as a result of the temperature differences.

Answer: A

3.

Which of the following statements about acids correct

I. They react with the calcium carbonate to give a gas

II. They turn red litmus paper blue

III. They react with reactive metals to give a gas

IV. They turn blue litmus paper red

A.

I, II and IV only

B.

I, II and III only

C.

II, III and IV only

D.

D. I, III and IV

Answer: D

An acid is a substance that donates protons (in the Brønsted-Lowry definition) or accepts a pair of valence electrons to form a bond (in the Lewis definition). acid, any substance that in water solution tastes sour, changes the color of certain indicators (e.g., reddens blue litmus paper), reacts with some metals (e.g., iron) to liberate hydrogen, reacts with bases to form salts, They react with the calcium carbonate to give a gas and promotes certain chemical reactions (acid catalysis).

4.

The first step in the digestion of fats in the body is that

A.

bile breaks down the fat in the gall bladder.

B.

bile breaks down the fat in the duodenum.

C.

lipase breaks down the fat in the pancreas.

D.

lipase breaks down the fat in the ileum.

Answer: B

5.

The nearest planet to the sun in the solar system is

A.

Earth

B.

Mars

C.

Mercury

D.

Venus

Answer: C

Mercury is the smallest planet in our solar system and nearest to the Sun, Mercury is only slightly larger than Earth's Moon.

6.

Which of the following controls the amount of light that enters the eyes?
A.
The cornea
B.
The iris
C.
The lens
D.
The pupil
E.
The retina

Answer: B

7.

Which of the following is likely to happen when the relative humidity is high?

A.

It is likely to rain

B.

It is likely to be dry

C.

It is likely to be sunny

D.

The day will be hot

E.
It will be windy

Answer: A

8.

Which of the following substances are components of a fertile soil?

A.

Nitrogen and phosphorus

B.

Phosphorous and sulphur

C.

Phosphorous, calcium and sulphur

D.

Calcium, sulphur, nitrogen and phosphorous

E.

Nitrogen, calcium and phosphorous

Answer: D

9.

A metal displaces 5.0 cm3 of water when it is totally immersed. If the mass of the metal is 35.0g, calculate its density.

A.

7.0 g cm-3

B.

30.00 g cm-3

C.

40.00 g cm-3

D.

175.00 g cm-3

Answer: A

Density

Density = Mass Volume

Mass = 35.0 g
Volume = 5.0 cm3

Density = 35.0 g 5.0  cm2 = 7 g cm-3

10.

Arrange the following sources of water in the order of increasing contamination.

I. Rain
II. Stream
III. Well
IV. Borehole

A.

I, II, IV, III

B.

II, III, I, IV

C.

I, IV, III, II

D.

III, II, IV, I

Answer: C

Increasing order of contamination means from the least contaminated to the most contaminated

11.

The major charge carriers in p-type semiconductors are

A.

anions

B.

electrons

C.

holes

D.

neutral

Answer: C

Holes and electrons are the two types of charge carriers responsible for current in semiconductor materials. A hole is the absence of an electron in a particular place in an atom. In P-type semiconductor material, holes are the majority carriers and electrons are the minority carriers while in N-type semiconductor material, electrons are the majority carriers and holes are the minority carriers

12.

The solid component found on the filter paper and the liquid component that flows into a container during filtration are respectively called

A.

filtrate and residue.

B.

condensate and residue.

C.

residue and filtrate.

D.

residue and condensate

Answer: C

The solid that remains on the filter paper is called the residue, and the liquid that passes through the filter paper is called the filtrate

13.

A fish dies shortly after being removed from water. This is because it

A.

cannot swim

B.

is streamlined

C.

is hot on land

D.

has scales

E.
cannot respire

Answer: E

14.

The function of the lungs is to

A.

maintain a constant amount of water in the body.

B.

absorb oxygen from the blood.

C.

absorb carbon dioxide from the blood.

D.

maintain the temperature of the body constant.

Answer: C

How the lungs work

Every cell in your body needs oxygen to live. The air we breathe contains oxygen and other gases. The respiratory system's main job is to move fresh air into your body while removing waste gases.

Once in the lungs, oxygen is moved into the bloodstream and carried through your body. At each cell in your body, oxygen is exchanged for a waste gas called carbon dioxide. Your bloodstream then carries this waste gas back to the lungs where it is removed from the bloodstream and then exhaled. Your lungs and respiratory system automatically perform this vital process, called gas exchange.

15.

Which of the following life activities are common to both plants and animals?

I. Feeding
II. Locomotion
III. Respiration

A.

I and II only

B.

I and III only

C.

II and III only

D.

I, II and III

Answer: B

16.

The sun and the planets form the

A.

atmosphere.

B.

constellation.

C.

milky way.

D.

solar system.

E.

universe.

Answer: D

17.

Which of these is not a characteristic of all living things?

A.

Transpiration

B.

Growth

C.

Reproduction

D.

Feeding

E.

Respiration

Answer: A

18.

Which of the following is not a soil nutrient?

A.

Hydrogen

B.

Nitrogen

C.

Potassium

D.

Calcium

E.

Phosphorus

Answer: A

19.

Which of the following properties is true about all matter? Matter has

A.

volume and fixed shape.

B.

volume and mass.

C.

mass and indefinite volume.

D.

density and fixed shape.

Answer: B

20.

When a thermometer is put in hot water, the mercury level rises because the mercury increases in

A.

density.

B.

mass.

C.

volume.

D.

weight.

Answer: C

21.

The second stage in the life cycle of a mosquito is the

A.

egg

B.

imago

C.

larva

D.

pupa

Answer: C

22.

Which of the following substances is a mixture?

A.

Water

B.

Sodium chloride

C.

Sodium chloride solution

D.

Iron filing

Answer: C

23.

In all machines, the efficiency is

A.

always 100%

B.

less than 100%

C.

more than 100%

D.

always 0%

Answer: B

24.

The main reason for staking tomato is to ensure

A.

bigger fruit development.

B.

air circulation on the farm.

C.

upright growth of the plant.

D.

that fruits do not get rotten.

Answer: D

Staking tomatoes provides support to help keep plants off the ground while assisting in their upward growth habit.

Because many diseases and insects start at the ground level, using a structured system to keep them away from ground contact is prudent.

Staking can also be used to prevent the fruit from beginning to rot as it sits on the ground as the stalk grows overtime.

25.

A piece of stone sinks in water because

A.

its density is the same as that of water

B.

it is able to displace its own weight of water

C.

its density is less than that of water

D.

its density is greater than that of water

E.
the water contains air which allows the stone to sink

Answer: D

26.

A drawing of magnetic line of force provides information on the

A.

source of the field.

B.

type of magnet.

C.

strength of the field.

D.

length of the magnet.

Answer: A

27.

The mosquito and housefly are harmful in that they

A.

suck blood.

B.

bite and cause pain.

C.

settle on food.

D.

spread diseases.

Answer: D

28.

An example of a third class lever is

A.

wheelbarrow.

B.

sugar tongs.

C.

pair of scissors.

D.

crowbar.

Answer: B

29.

Which of the following metals is an alloy?

A.

Aluminium

B.

Brass

C.

Copper

D.

Iron

E.

Zinc

Answer: B

30.

Young rabbits are called

A.

bunnies

B.

cubs

C.

fingerlings

D.

kids

Answer: A

31.

Which of the following energy changes takes place when a church bell is tolled?

A.

Potential energy to kinetic energy

B.

Kinetic energy to sound energy

C.

Potential energy to sound energy

D.

Chemical energy to heat energy

E.
Sound energy to Kinetic energy

Answer: B

32.

Use the information below to answer the question that follow.

 

A solid X reacted with a liquid Y to form a salt and water only. A portion of liquid Y turned blue litmus paper red. Solid X did not dissolve when a portion of it was placed in water and stirred.

 

Solid X could be said to be

A.

an acid.

B.

an alkali.

C.

a base.

D.

a salt.

Answer: C

33.

What type of energy is lost when sweat evaporates from the body?

A.

light energy

B.

mechanical energy

C.

chemical energy

D.

Heat energy

E.
Electrical energy

Answer: D

34.

Which of the following step(s) is/are required in the scientific method?

I. Formulation of hypothesis

II. Identification of the problem

III. Experimentation

A.

I only

B.

II only

C.

II and III only

D.

I, II and III

Answer: D

35.

Which of the following organisms improves soil fertility?

A.

Caterpillar

B.

Millipede

C.

Nematode

D.

Rat

Answer: B

36.

The study of the soil profile of an area helps the farmer to

A.

control weed growth.

B.

determine the soil temperature.

C.

determine the types of crops to grow.

D.

know the pesticides to use.

Answer: C

37.

In the digestive system of ruminants, vitamins are synthesized in the

A.

abomasum.

B.

omasum.

C.

reticulum.

D.

rumen

Answer: D

38.

The three states of matter are

A.

Water, liquid and gas

B.

Earth, liquid and gas

C.

Solid, liquid and air

D.

Gas, earth and water

E.
Gas, liquid and solid

Answer: E

39.

The physical change(s) that take(s) place when a piece of ice is heated continuously for a long time can be represented by

A.

solid → vapour

B.

vapour → solid → liquid

C.

solid → liquid → vapour

D.

liquid → vapour

Answer: C

Ice is in the solid state. When heated, it melts into the liquid state (water) and which (water) when further heated vapourizes.

40.

Which of these is not a sense organ?

A.

Eye

B.

Ear

C.

Nose

D.

Skin

E.

Heart

Answer: E

THEORY QUESTIONS

1.

a)

i)

What is a transistor?

ii)

Give two uses of a transistor.

b)

Mention the suitable solvent for each of the following solutes:

i)

grease;

ii)

ink stain;

iii)

starch;

iv)

cube sugar;

v)

oil paint;

vi)

iodine.

c)

i)

What is a respiratory organ?

ii)

Name two structures of the respiratory system of humans.

d)

i)

What is agricultural chain?

ii)

Name two types of agricultural chain.

a)

i)

A transistor is a three terminal (a base, emitter and collector) semiconductor device.

ii)

Uses of a transistor

1. Used as an amplifier
2. Used as a switch
3. Used as a rectifier
4. Used for tuning in radios
5. Used as a voltage/current regulator

b)

i)

Suitable solvents for grease

1. Petrol
2. Kerosene
3. Methylated spirit

ii)

Suitable solvents for ink stain

1. Milk
2. Alcohol
3. Parazone
4. Shaving cream
5. Kerosene

iii)

Suitable solvents for starch

1. Alcohol
2. Acetone

iv)

Suitable solvents for cube sugar

Water

v)

Suitable solvents for oil paint

1. Turpentine
2. Kerosene
3. Petrol
4. Thinner

vi)

Suitable solvents for iodine

1. Ethanol/Alcohol
2. Potassium iodide solution

c)

i)

Respiratory organ is an organ used by living organisms for gaseous exchange

ii)

Structures of the respiratory system of humans

1. Trachea
2. Lungs
3. Alveolus
4. Larynx
5. Diaphragm
6. Bronchus/Bronchi
7. Nostril/Nose
8. Nasal cavity
9. Intercostals muscle
10. Ribs
11. Pharynx

d)

i)

Agricultural chain is a series of stages that are connected in the production of agricultural goods/services.

ii)

Types of agricultural chain

1. Production
2. Processing
3. Supply
4. Value

2.

(a)

(i)

State what happens when photosynthesis occurs in a leaf.

(ii)

What is pollination?

(b)

Explain briefly why the mass of lumpy charcoal remains unchanged when ground into powder but the mass of the same lump changes when heated to burn.

(c)

(i)

What is a physical quantity?

(ii)

State two physical quantities

(d)

State two importance each of:

(i)

light;

(ii)

temperature;

in crop production

(a)

(i)

What happens when photosynthesis occurs in a leaf

Plants take in carbon dioxide (CO2) and water (H2O) from the air and soil. Within the plant cell, the water is oxidized, meaning it loses electrons, while the carbon dioxide is reduced, meaning it gains electrons. This transforms the water into oxygen and the carbon dioxide into glucose. Light is also absorbed by chlorophyll

(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

(b)

Grinding lumpy charcoal is a physical change and therefore the components remain unchanged but burning charcoal is a chemical change and some of the components are released into the atmosphere

(c)

(i)

A physical quantity is any physical property of a material or substance that can be quantified, that is, can be measured using numbers

(ii)

1. Mass
2. Force
3. Density
4. Length
5. Temperature
6. Volume
7. Electric current
8. Velocity
9. Time

(d)

(i)

Importance of light in crop production

1. Needed for photosynthesis
2. Affects developments of fruits/growth of vegetative parts of crops
3. Absence of light results in weak stem

(ii)

Importance of temperature in crop production

1. Required for germination
2. Delays ripening of fruits when temperature is low
3. High temperature can cause evaporation from the soil causing water deficit for crops
4. High temperature can scorch the leaves of crops
5. Needed for photosynthesis/growth and development of plants

3.

(a)

Draw and label a diagram to show how the eclipse of the sun is formed.

(b)

(i)

What is a lever?

(ii)

Classify the following as first class lever, second class lever or third class lever by copying and completing the table below:

Beam balance, crowbar, wheel barrow, a pair of scissors, claw hammer, sugar tong, human fore-arm and bottle opener

First class lever Second class lever Third class lever

(c)

(i)

What is pollination?

(ii)

Give two agents of pollination.

(d)

Name three excretory organs and the products they excrete.

(e)

(i)

What is an alloy?

(ii)

What are the compositions of each of the following alloys?

Bronze, Brass, Steel and Duralumin

(f)

Sodium chloride is prepared by the reaction between dilute hydrochloric acid and sodium hydroxide solution. Write down the equation for this reaction.

(a)

(b)

(i)

A lever is a simple machine which consists of a rigid bar/rod free to turn about a fixed turning point called the fulcrum/pivot.

(ii)

First class lever Second class lever Third class lever

Crowbar
Claw hammer
A pair of scissors
Beam balance

Wheel barrow
Bottle opener

Sugar tong
Human fore-arm

(c)

(i)

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

(ii)

Agents of pollination

1. Wind
2. Animal (Birds, Bats, Man)
3. Insect
4. Water/Rain

(d)

Excretory Organs Excretory Products
Skin Sweat/water and salt/water and urea
Kidney Urine/urea/water and salt
Lungs Carbon dioxide/water vapour
Liver Bile pigments

(e)

(i)

An alloy is a uniform/homogeneous mixture of a metal and another metal or a non-metal.

(ii)

Compositions of alloys

Bronze → Copper and Tin
Brass → Copper and Zin
Steel → Iron and Carbon
Duralumin → Aluminium, Magnesium, Copper and Manganese

(f)

NaOH + HCl → NaCl + H2O

4.

(a)

(i)

Given a flashlight, a tennis ball and a screen, draw a diagram to show how a shadow can be formed.

(ii)

A student seeking to determine the volume of an irregular body of mass 4 kg used a graduated cylinder in an experiment.

Fig. 2 illustrates two key stages of the experiment where A indicates a setup before the irregular body was immersed and B indicates the same setup after the irregular body was immersed.

Determine the density of the irregular body.

(iii)

State two precautions that must be taken to obtain reliable results.

(b)

State three safety precautions to prevent accidents during the use of liquefied petroleum gas in the home.

(c)

Explain briefly the scientific princible underlying each of the following waste management practices:

(i)

Composting;

(ii)

Recycling;

(iii)

Incineration.

(d)

The digestive system of two domestic animals were provided. One is that of a goat and the other is that of a rabbit.

Outline three features that would help to differentiate between the two digestive systems.

(a)

(i)

How a shadow can be formed

(ii)

Change in volume = (75 - 50) cm3 = 25 cm3

Density = Mass Volume

Method I

Calculating density in kg dm-3

Note: when using the mass in kilogram (4 kg) the volume must be in dm3.

25 cm3 = 25 1000 = 0.025 dm3

Density = 4 0.025 = 160 kg dm-3 or 160 kg/dm3

Method II

Calculating density in g cm-3

Note: when expressing the density in g cm-3, the kilogram must be changed to gram.

4 kg = 4 x 1000 g = 4000 g

Density = 4000 25 = 160 g cm-3 or 160 g/cm3

Note: Mark is deducted for answer without correct unit

(iii)

Precautions that must be taken to obtain reliable results

1. The object should be dropped gently to avoid splashing the water
2. The volume should be read at the correct meniscus

(b)

Safety precautions to prevent accidents during the use of liquefied petroleum gas in the home

1. Turn the knob off when the cylinder is not in use
2. Keep doors and windows to the kitchen open
3. Cylinders of LPG should be stored preferably in the open air
4. The cylinder should not be exposed to heat/flame
5. Strike match before opening cylinder

(c)

Scientific princible underlying waste management practices:

(i)

Composting

1. Microorganisms in organic matter make use of oxygen
2. and decompose/breakdown organic matter into nutrients

(ii)

Recycling

1. Involves processing/conversion/physically and chemically changing waste materials
2. Into new products

(iii)

Incineration

1. Involves burning of waste materials at high temperatures
2. and converting them into gas/ash to destroy contaminants

(d)

Goat

Four chambered stomach

Rabbit

One chambered stomach

5.

a)

State three ways in which mulching restores soil resources.

b)

i)

Name the two elements that combines to form ammonia gas.

ii)

Write a balanced chemical equation for the formation of ammonia from the elements named in (i).

c)

The following information is on the feeding habits of some organisms:

i)

man feeds on grasscutter;

ii)

toad feeds on grasshopper;

iii)

snake feeds on toad;

iv)

goat feeds on grass;

v)

man feeds on hawk;

vi)

grasshopper feeds on grass;

vii)

hawk feeds on snake;

viii)

grasscutter feeds on grass.

Use all the information given above to construct a food web.

d)

i)

What is a galaxy?

ii)

State the relationship between stars and galaxies.

iii)

Explain briefly the term milky way.

a)

Ways in which mulching helps to restores soil resources

1. It checks growth of weeds (which will otherwise take water out of the soil)
2. It improves soil structure/texture (which in turn improve the soil water holding capacity/soil drainage)
3. It reduces/checks soil erosion
4. It reduces water loss from the soil by evaporation/increases water-holding capacity of soil
5. It adds nutrients/organic matter to the soil
6. It helps maintain soil temperature
7. Conserves soil nutrients
8. Improves activity of soil organisms

b)

i)

The two elements that combines to form ammonia gas

1. Nitrogen
2. Hydrogen

ii)

Balanced chemical equation for the formation of ammonia

N2 + 3H2 → 2NH3

c)

d)

i)

Galaxy is a group of stars.

OR

Galaxy is a system of stars,gases,dust/dark matter held together in the heavens/space.

OR

Galaxy is a collection of billions of stars that show a common gravitational link.

ii)

Relationship between stars and galaxies

Galaxies are held together by gravitational attraction much like a solar system while stars in the solar systems combine to form galaxies

OR

Stars makes up the galaxies

OR

Galaxies are made up of several billions of Stars

iii)

Milky way is the galaxy that contains the solar system and the earth.

OR

Milky way is a hazy band of light seen in the night sky formed from stars that cannot be individually distinguished by the naked eye.

6.

a)

i)

State two physical properties of water.

ii)

Using litmus paper, explain why water is neutral.

b)

Give one function of each of the following nutrients in plants:

i)

Nitrogen;

ii)

Potassium.

c)

i)

State two human activities that disrupt the carbon cycle.

ii)

State two effects of the disruption of the carbon cycle on the environment.

d)

i)

What is density of a body?

ii)

A body of mass 50kg has a density of 2kg/m3. Calculate the volume of the body.

a)

i)

Physical properties of water

1. Odourless
2. Colourless
3. Tasteless/insipid
4. Freezes at 0oC
5. Boils at 100oC
6. Universal solvent
7. Exists in three states
8. Has a density of 1g/cm3 (at 4oC)
9. It is transparent
10. It has a neutral pH/pH = 7
11. High surface tension

ii)

Why water is neutral

When red litmus paper or blue litmus paper is dropped in a sample of water, there is no change in colour.

b)

i)

Functions of nitrogen in plants

1. For plant growth/vegetative growth
2. Increases yield of straw
3. A constituent of organic compound of plants
4. For plant development
5. Increases seed and fruit production
6. To make proteins
7. To make chlorophyll

ii)

Functions of potassium in plants

1. Plays an important role in plant metabolism
2. Plays an important role in translocation of starch to growing parts
3. Plays an important role in carbohydrate formation
4. Neutralization of organic acids
5. Strengthens straw and stalk of plants
6. Aids absorption of nutrients
7. Helps to reduce diseases in plants
8. Helps to produce quality fruit and promotes seed development
9. Activates enzymes for photosynthesis and respiration
10. Helps build proteins
11. Aids absorption of nutrients

c)

i)

Human activities that disrupt the carbon cycle

1. Destruction of forest/cutting of trees/lumbering
2. Bush burning
3. Burning of fossil fuels

ii)

Effects of the disruption of the carbon cycle on the environment

1. Global warming/rise in temperature/greenhouse effect/affects climate
2. Reduction in oxygen
3. Rise in sea level/flooding/melting of ice
4. Animals/plants become endangered/extinct
5. Prolonged drought
6. Reduction in rainfall

d)

i)

Density is the mass per unit volume of a body

OR

Density = Mass Volume

ii)

Density = Mass Volume

Density x Volume = Mass

Divide both sides by Density

Volume = Mass Density

Mass = 50 kg
Density = 2kg/m3

Volume = 50 2 = 25 m3