KUULCHAT
SCIENCE MOCK
OBJECTIVE TEST
1.
The portion of air which acts as a solvent is
A.
oxygen.
B.
carbon (IV) oxide.
C.
nitrogen.
D.
an inert gas.
Answer: C
Since the concentration of nitrogen (N2) is maximum in air (78%). Hence, the solvent is Nitrogen gas and other gases like Oxygen and other gases act as solute.
2.
Which of the following substances is a solid-gas mixture?
A.
Lather
B.
Bronze
C.
Steel
D.
Smoke
Answer: D
3.
When the brakes of a bicycle in motion are applied for a long time the wheels become hot. This is because of a change of energy from
A.
kinetic energy to potential energy.
B.
potential energy to kinetic energy.
C.
potential energy to heat energy.
D.
kinetic energy to heat energy.
Answer: B
Kinetic energy is the energy a body possesses by virtue of being in motion
Potential energy is the energy a body possesses by virtue of its position relative to other objects.
Heat is the transfer of energy from a high-temperature body to a lower-temperature one.
4.
Which of the following statement(s) about pressure in fluids is/are correct? Pressure
I. decreases with depth
II. increases with depth
III. does not depend on the area
A.
I only
B.
II only
C.
I and II only
D.
II and III only
Answer: B
The pressure in a liquid is different at different depths. Pressure increases as the depth increases. The pressure in a liquid is due to the weight of the column of water above. Since the particles in a liquid are tightly packed, this pressure acts in all directions. For example, the pressure acting on a dam at the bottom of a reservoir is greater than the pressure acting near the top. This is why dam walls are usually wedge-shaped. The greater pressure at the bottom would give a greater ‘force per unit area’ on the wall.
5.
Which of the following processes involves the solid state of matter?
A.
Boiling
B.
Condensation
C.
Evaporation
D.
Melting
Answer: D
6.
Droplet infection is the method by which
A.
disease are transmitted from animals to plants.
B.
infected animals are processed.
C.
human beings protects themselves from diseases.
D.
diseases are spread through the air.
Answer: D
7.
An example of leafy vegetable crops is
A.
cucumber.
B.
lettuce.
C.
okro.
D.
onion.
Answer: B
8.
Which of the following materials transforms electrical energy into light energy?
A.
Electric bell
B.
Filament bulb
C.
Electric guitar
D.
Lantern
E.
Radio
Answer: B
9.
Which of the following metals will produce a gas when placed in lime juice?
A.
Copper
B.
Lead
C.
Magnesium
D.
Silver
Answer: C
10.
Which of the following bodies is a satellite of the earth?
A.
Mars
B.
Sun
C.
Venus
D.
Moon
E.
Mercury
Answer: D
11.
Cultural practices are activities undertaken on a farm
A.
after harvesting and before processing.
B.
before maturity and after harvesting.
C.
after planting and before harvesting.
D.
before transplanting seedling.
Answer: C
12.
Which of the following organisms is at the beginning of a food chain?
A.
Fish
B.
Grass
C.
Locust
D.
Mosquito
Answer: B
The primary producers are the beginning of a food chain. They are autotrophs and are most often photosynthetic organisms such as plants, algae, or cyanobacteria. The organisms that eat the primary producers are called primary consumers. Primary consumers are usually herbivores, plant-eaters, though they may be algae eaters or bacteria eaters.
13.
Which of the following diseases is spread by a mosquito?
A.
Blindness
B.
Cholera
C.
Dysentery
D.
Elephantiasis
Answer: D
14.
An example of a source of energy which is non-renewable is
A.
petroleum.
B.
solar.
C.
tide.
D.
wind.
Answer: A
15.
Which of the following processes results in the formation of new substances?
A.
Heating camphor
B.
Cooling water to form ice
C.
Adding saliva to cooked yam
D.
Mixing iron dust and sand together
Answer: C
On addition of saliva which contains an amylase to the cooked yam, a starch digesting enzyme (chemical compound that catalyzes the breakdown of starch), the starch gradually converts to sugar (new substance formed).
16.
Which of the following gives the correct order by which blood circulates continuously through the circulatory system?
A.
Heart → veins → organs → arteries → heart
B.
Heart → arteries → organs → veins → heart
C.
Heart → arteries → veins → organs → heart
D.
Heart → organs → arteries → veins → heart
E.
Heart → veins → arteries → organs → heart
Answer: B
17.
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
18.
Decay is an important biological process because it brings about the
A.
formation of nutrients in living organisms
B.
manufacture of cells of living organisms
C.
production of oxygen by plants
D.
release of nutrients from dead organisms
E.
release of waste substances from bacteria
Answer: D
19.
About 55% of blood is made up of the plasma while the remaining 45% is made up of
A.
Cells
B.
Cochlea
C.
Iris
D.
Retina
E.
Trachea
Answer: A
20.
The force which tends to pull an object in a circular motion towards the centre of the circle is called
A.
centripetal force.
B.
electrostatic force.
C.
gravitational force.
D.
magnetic force.
Answer: A
21.
One similarity of physical and chemical changes is that both
A.
are easily reversible
B.
result in change of state of matter
C.
produce no change in mass
D.
are accompanied by great heat change
Answer: B
Physical and chemical changes are similar because matter experiences a change in state, Physical
changes are different because matter remains the same substance, just in a different state,
whereas chemical changes change the matter. A chemical change results from a chemical reaction,
while a physical change is when matter changes forms but not chemical identity. Examples of chemical
changes are burning, cooking, rusting, and rotting. Examples of physical changes are boiling,
melting, freezing, and shredding.
22.
The instrument used in measuring the speed of wind is called:
A.
Thermometer
B.
Wind Vane
C.
Photometer
D.
Anemometer
E.
Hygrometer
Answer: D
23.
Which of the following is the sense organ for sight?
A.
Skin
B.
nose
C.
eye
D.
ear
E.
tongue
Answer: C
24.
The female part of a flower is called the
A.
filament.
B.
petal.
C.
pollen grain.
D.
sepal.
E.
Style.
Answer: E
25.
The number of p-n junctions in a transistor is
A.
1
B.
2
C.
3
D.
4
Answer: B
26.
The term leaching in soils refers to .....
A.
accumulation of organic matter
B.
decomposition of plant material
C.
fixation of nitrogen
D.
removal of soil nutrients by water
Answer: D
27.
Which of the following activities are cultural practices in the cultivation of cabbage?
I. Prunning
II. Weeding
III. Watering
A.
I and II only
B.
I and III only
C.
II and III only
D.
I, II and III only
Answer: D
28.
The importance of fuse in an electrical circuit is to
A.
regulate the voltage.
B.
prevent damage to electrical appliances.
C.
alter the flow of current in the circuit.
D.
minimize the use of current.
Answer: B
29.
When a stick is dipped into a pool of water, it appears to
A.
be longer than its length.
B.
ben away from the surface.
C.
be seen straight in the water.
D.
bend towards the surface.
Answer: D
30.
A rheostat is used in an electric circuit in order to
A.
increase electric current only.
B.
decrease electric current only.
C.
keep electric current constant.
D.
increase and decrease electric current.
Answer: D
31.
When the testa of a soaked bean is removed, the seed is seen to be made up of
A.
cotyledons.
B.
embryos.
C.
micropyles.
D.
radicles.
Answer: A
32.
The efficiency of a machine is always less than 100% because part of the energy input is used to
A.
stop the machine after working.
B.
perform useful work of the load.
C.
overcome friction.
D.
lift the machine up.
Answer: C
33.
Which of the following food substances is not oxidized during respiration?
A.
Fatty acids
B.
Amino acids
C.
Glucose
D.
Cellulose
E.
Vitamins
Answer: E
34.
The chemical formula H2 represents
A.
two atoms of hydrogen.
B.
two neutrons of hydrogen.
C.
two ions of hydrogen.
D.
two molecules of hydrogen.
Answer: A
35.
The shedding of leaves by plants during the dry season protects them against
A.
bush fire
B.
cold weather
C.
plant-eating animals
D.
heat loss
E.
water loss
Answer: E
36.
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.
37.
Which of the following statements describes the nature of light?
A.
It passes through all objects.
B.
It is absorbed at a polished surface.
C.
It travels in a straight line.
D.
It is always reflected in a medium.
Answer: C
Light travels in a straight line
From the above experiment when one of the cardboard sheets is moved to either side, it is observed that the flame is no longer visible. This is because the light cannot bend to pass through the hole.
Examples of Straight-Line Motion of Light
1. When a lamp, torch, or another source of light emits light, it travels in a straight line
2. When sunlight enters a dusty environment through tiny holes, a straight-line trail of light is apparent
3. The object will become invisible when an opaque object is placed in front of it. The reason for this is that an opaque object prevents light from bending through its corners
38.
The practice of reducing the number of seedlings per stand for better growth is known as
A.
earthing up.
B.
filling in.
C.
pricking out.
D.
thinning out.
Answer: D
Thinning out: This is the removal of some plants from the area grown with seeds. This is done mainly to make room for the seeds to grow well.
Earthing up: is a farming technique that involves mounding soil around the base of a plant, usually a crop. This technique has been used for centuries in agriculture and has a variety of benefits for crops. One of the main reasons for earthing up is to protect the plant from extreme weather conditions.
39.
Which of the following metals is used for making roofing sheets?
A.
Zinc
B.
Silver
C.
Mercury
D.
Tin
E.
Aluminium
Answer: E
40.
The hatching of eggs into chicken depends on constant supply of
A.
water
B.
feed
C.
pressure
D.
heat
E.
light
Answer: D
THEORY QUESTIONS
1.
a)
An atom Y has atomic number 12. It loses two electrons in order to be stable.
i)
State the proton number of the atom before it loses electrons.
ii)
State the electron number of the atom:
α)
before it loses electrons.
β)
after losing electrons.
iii)
Name the type of ion formed by the atom when it loses two electrons.
b)
Name four farming system in crop production.
c)
i)
What is dispersal of seed?
ii)
State two characteristics of seeds dispersed by wind.
d)
Explain the term forward bias of a p-n junction diode.
a)
i)
In a neutral atom, number of electrons = number of protons
12 electrons = 12 Protons
Proton number = 12
ii)
α)
Electron number before losing 2 electrons
Electron number = 12
β)
Electron number after losing 2 electrons
Electron number = 12 - 2 = 10
iii)
Type of ion formed after losing 2 electrons
Cation/positively charged ion is formed after losing the two electrons
b)
Farming systems in crop production
1. Crop rotation
2. Land rotation
3. Monoculture
4. Mono cropping
5. Mixed cropping
6. Shifting cultivation
7. Mixed farming
8. Organic farming
9. Ecological farming/Eco-farming
c)
i)
Dispersal of seed is a process by which seeds are carried away from the parent plant.
ii)
Characteristics of seed dispersed by wind
1. Seeds are very small
2. They are very light
3. They have hair
4. They have wing-like structures
d)
Forward bias is when the positive terminal of an electric source is connected to the p-type of the diode and the negative terminal of the source is connected to the n-type of the diode resulting in the flow of charges or current.
2.
(a)
(i)
What is the difference between self-pollination and cross-pollination?
(ii)
Name two agents of cross-pollination.
(b)
A ray of light strikes the surface of a plane mirror at an oblique angle.
Draw a ray diagram to show each of the following:
(i)
the normal
(ii)
the incident ray
(iii)
the reflected ray
(iv)
the angle of incidence
(v)
the angle of reflection
(c)
Give one property of the image formed by a plane mirror.
(d)
(i)
Carbon dioxide is prepared in the laboratory by pouring some dilute hydrochloric acid on calcium carbonate. Give a balanced equation for this reaction.
(ii)
How would you test for carbon dioxide?
(iii)
Give one use of carbon dioxide.
(a)
(i)
Difference between self-pollination and cross-pollination
Self-pollination is the transfer of pollen grains from the anther of a flower to the stigma of the same flower whereas cross-pollination is the transfer of pollen grains from the anther of a flower to the stigma of another flower on another plant of the same species.
(ii)
Agents of cross-pollination
1. Bees
2. Birds
3. Bats
4. Insects
5. Wind
6. Water/rain
7. Man
(b)
(c)
Properties of the image formed by a plane mirror
1. The image formed is laterally inverted
2. The image formed is virtual
3. The image formed is same size as the object
4. The image formed is upright/erect
5. Image distance from the mirror is the same as the object distance
(d)
(i)
CaCO3 + 2HCl → CaCl2 + H2O + CO2
(ii)
How to test for carbon dioxide
1. Pass the gas through limewater
2. The colourless limewater turns milky/chalky when there is the presence of carbon dioxide
(iii)
Uses of carbon dioxide
1. Used in fruit preservation
2. Used in the manufacturing of soft drinks
3. Used as fire extinguisher
4. Used as refrigerant
3.
a)
The diagram below are illustrations of two cells labelled A and B
Study the diagram carefully and answer the questions that follow.
i)
Name each of the parts labelled I, II, III and IV.
ii)
Which of the parts named in (a)(i) is the same as the parts labelled VI and IX in cell B?
iii)
Which of the cells is a plant cell?
iv)
Give two reasons for the answer given in (a)(iii).
v)
Tabulate two differences between the parts labelled I and V.
b)
The diagram below is an illustration of an experiment carried out in the laboratory.
Study the diagram carefully and answer the questions that follow.
i)
Read and record the:
(α) mass of irregular object (M) in I
(β) Volume of water (V1) in II
(γ) Volume of water (V2) in III
ii)
Determine the volume of the irregular object.
iii)
Calculate the density of the irregular object.
iv)
Name the instrument that could be used to measure the mass of an irregular object.
v)
State one precaution to be taken in performing the experiment.
c)
The following activities were performed in the laboratory by groups of pupils.
Study the activities and answer the questions that follow.
i) Camphor was heated.
ii) Wood was burnt.
iii) Iron nails were heated strongly.
iv) Sodium chloride was dissolved in water.
i)
Which of the following activities are:
(α) chemical processes;
(β) physical processes.
ii)
Give two reasons why the activities listed in:
(α) (i)(α) are chemical processes;
(β) (i)(β) are physical processes.
iii)
Give two examples of physical change that take place in your environment.
d)
A farmer cultivated soya bean, yam and maize on a farm in a rotational programme as illustrated below.
Study the diagram carefully and answer the questions that follow.
i)
Copy and complete the table.
ii)
List three principles to consider when planning this rotational programme.
iii)
Give two reasons for selecting the crop named for V in plot 1 year 3.
iv)
State one advantage of practising this farming system.
a)
(i) I = cell/plasma membrane, II = cytoplasm, III = nucleus , IV = vacuole
(ii) I is the same as VI (Cell membrane) and IV is the same as IX (Vacuole)
(iii) Diagram B
iv)
Reasons
1. Presence of large/ single vacuole (IX)
2. Presence of cell wall (V)
3. Rectangular shape
4. Nucleus pushed to the side/periphery
5. Cytoplasm pushed to the side
v)
Differences between parts labelled I (Cell Membrane) and V (Cell Wall)
| I (Cell Membrane) | V (Cell Wall) |
| Present in all types of cells, in humans, animals, plants, bacteria, etc. | Present only in plants and in some fungi, bacteria, algae. |
| Semi-permeable | Completely or fully permeable |
| Flexible | Thick and rigid |
| Made up of proteins and lipids | Made up of cellulose |
b)
i)
(α) mass of irregular object (M) in I = 40 g
(β) Volume of water (V1) in II = 40 cm3
(γ) Volume of water (V2) in III = 60 cm3
ii)
Volume of the irregular object = 60 cm3 - 40 cm3 = 20 cm3
iii)
Density
Density =
Density = = 2 g/cm3 or 2 gcm-3
iv)
Instruments for measuring mass of an irregular object
1. Beam balance
2. Top pan balance
3. Electronic balance
iv)
Precautions to be taken in performing the experiment
1. The object should be lowered gently into the water in the cylinder
2. Volume of the liquid should be read from the base of the meniscus or at the eye level
3. The measuring cylinder should be placed on a flat surface
c)
i)
(α) chemical processes
II and III
(β) physical processes
I and IV
ii)
(α) Why chemical processes
1. The initial/original substance cannot be gotten back easily/irreversible
2. New substance formed
3. Change in mass
4. Accompanied by appreciable heat change
(β) Why physical processes
1. The initial/original substance can be gotten back easily/reversible
2. No new substance formed
3. No change in mass
4. Not accompanied by appreciable heat change
iii)
Examples of physical change
1. Expansion of metal on heating
2. dissolving sugar or salt in Water
3. Boiling of water
4. Melting of ice
5. Breaking/crushing of any Object
d)
i)
| Year\Plot | 1 | 2 | 3 |
| 1 | maize | soyabean | yam |
| 2 | yam | maize | soyabean |
| 3 | soyabean | yam | maize |
ii)
Principles to consider when planning for rotational programme
1. Deep rooted crops should be followed by shallow rooted crops
2. Crops of the same family/class should not follow each other
3. Crops that use the same soil nutrients should not follow each other
4. Leguminous crops should be included in the cycle
5. A fallow period may be included in the crop rotation programme
6. Crops which attract the same diseases and pests should not follow each other
iii)
Reasons for selecting the crop named V (Soyabean)
1. Soyabean is a legume and therefore builds up soil fertility
2. Yam is a deep rooted crop and should be followed by soyabean which is a shallow rooted crop
3. Yam is a heavy feeder and must have taken good part of the nutrients
4. Yam and soyabean belong different classes of crops and therefore not likely to attract the same pests and diseases
5. Improves soil structure
iv)
Advantages of crop rotation
1. Increases soil fertility
2. Enhances soil structure
3. Prevents soil erosion
4. Improves soil nutrients and nutrient uptake regulation
5. Controls the spread of pests and diseases
6. Controls weed easily
7. There is effective use of the land
8. Harvest of different types of crops on the same piece of land
4.
a)
Describe briefly how the volume of an irregular shaped lead ball could be measured.
b)
State three characteristics of living things.
c)
i)
What is pollution?
ii)
Name one air pollutant.
d)
State three factors which influence vegetable crop production.
a)
How to measure the volume of an irregular object
1. Pour water into a measuring cylinder and take note of the volume (V1)
2. Gently drop the irregular object into the water and take the new volume recorded (V2)
3. Calculate the volume of the irregular object by subtracting the volume of the water (V1) from the final volume (V2)
4. Thus volume of the irregular object (ball) = V2 - V1
b)
Characteristics of living things
1. Respiration
2. Movement/Locomotion
3. Reproduction
4. Excretion
5. Feeding/Nutrition
6. Growth
7. Sensitivity/Irritability
c)
i)
Pollution is the introduction of waste/toxic/unwanted/harmful/dangerious substances into the environment which causes harm to humans and other living organisms.
ii)
Air Pollutants
1. Carbon monoxide (Carbon (II) oxide)
2. Smoke
3. Dust
4. Car Exhaust/Fumes/lead
5. Chloroflurocarbon/ CFC
6. Sulphur dioxide (Sulphur (IV) oxide)
7. Sulphur trioxide (Sulphur (VI) oxide
d)
Factors which influence vegetable crop production
1. Soil fertility/Soil type
2. Soil structure/texture/porosity
3. Temperature
4. Rainfall/Water
5. Sunlight
6. Wind
7. Soil pH
5.
a)
Name the four main parts of a flower.
b)
Give two external features of plants pollinated by wind.
c)
Construct a food chain using any four of the organisms listed below.
Goat, lizard, bird, snake, earthworm, grasscutter, grass, ant, cassava
d)
i)
The energy input of a machine is 7.5 J and the output energy is 5.0 J.
Calculate the efficiency of the machine.
ii)
Explain why the efficiency of a machine is always less than 1.
a)
The four main parts of a flower
1. Sepal/Calyx
2. Petal/Corolla
3. Stamen/Androecium (Filament and anther)
4. Pistil/Gynoecium (Style, stigma and ovary)
b)
External features of plants pollinated by wind
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
c)
Cassava/Grass → grasscutter → snake → bird
OR
Cassava → ant → lizard → snake
OR
Cassava → ant → bird → snake
d)
i)
Efficiency of a machine = x 100%
Efficiency of a machine = x 100%
7.5 =
Efficiency of a machine = 5 ÷ x 100%
Reciprocate the fraction at the right of the ÷ and change ÷ to multiplication (x)
Note: reciprocate means the numerator becomes the denominator and the denominator becomes the numerator.
Efficiency of a machine = 5 x x 100%
Note:
1. 5 divides itself 1 and 75, 15 times
2. 5 divides 15, 3 times and 10, 2 times
3. 2 x 100 = 200
Efficiency of a machine = % = 66.67%
ii)
Why the efficiency of a machine is always less than 1 or 100%
The efficiency of a machine is always less than 1 or 100% because part of the energy input is used to overcome friction and gravitational forces
OR
The efficiency of a machine is always less than 1 or 100% because part of the energy input is wasted in the machine
6.
(a)
In an experiment, a pupil took two empty Milo tins and made holes in their sides as shown in the diagram above. The pupil then filled the Milo tins with water.
(i)
Draw and label the diagrams to show what the pupil will observe in set-up A and set-up B.
(ii)
Explain the observations in set-up A and set-up B.
(iii)
What is the aim of set-up A?
(iv)
What is the aim of set-up B?
(b)
In an experiment, equal volumes of dilute hydrochloric acid (Solution A) and dilute sodium hydroxide (Solution B) are mixed together to form solution C.
(i)
What is the volume of solution C?
(ii)
Red litmus paper and blue litmus paper are dipped in turns into solutions A, B and C.
State the observations you will make in all six cases.
(iii)
Give the name of the reaction that took place between solution A and solution B.
(iv)
Identify solution C
(v)
State what will happen when solution C is heated.
(c)
The table below gives the steps that were followed in an experiment to test for starch in a green leaf freshly taken from a tree.
| Stages in the test for starch |
|
I. Leaf is put into boiling water for 1 minute II. Leaf is dipped in alcohol warmed in a hot water bath III. Leaf is washed in cold water IV. Leaf is dipped into iodine solution |
(i)
State the reason for carrying out each of the activities in stages I, II and III.
(ii)
What happens when the leaf is dipped in iodine solution?
(iii)
Give the colour changes of the leaf from the beginning of the experiment to the end of the experiment.
(iv)
Why is the alcohol warmed indirectly in a water bath?
(vi)
Explain what will be observed if the test is carried out on a leaf taken from a plant kept in a dark room for 1 day
(a)
(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.
(b)
(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)
| Solution | Red Litmus | Blue Litmus |
| Solution A | No change in colour/remains red | Turns red |
| Solution B | Turns blue | No change in colour/remains blue |
| Solution C | No change in colour/remains red | No change in colour/remains blue |
(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
(c)
(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.