KUULCHAT
SCIENCE MOCK
OBJECTIVE TEST
1.
It is easier to move a heavy load with a crowbar when the
A.
effort distance is shorter than the load distance.
B.
effort distance is longer than the load distance.
C.
effort distance is equal to the load distance.
D.
effort is equal to the load.
Answer: B
Mechanical Advantage =
Load Distance: is the distance between the pivot (fulcrum) and the load
Effort Distance: Is the distance between the pivot (fulcrum) and the effort
Since the effort distance is the numerator in the mechanical advantage formula, the greater it is than the load distance, the greater the mechanical advantage and the better the efficiency of the machine/lever.
2.
The male sperms fertilize the female eggs to form the
A.
embryo
B.
ovary
C.
ovum
D.
placenta
E.
uterus
Answer: A
3.
A substance is termed combustible if it
A.
easily catches fire.
B.
dissolve common salt.
C.
sublimes at room temperature.
D.
boils at 100oC.
Answer: A
4.
The human male sex cell that takes part in reproduction is the
A.
penis
B.
scrotum
C.
sperm
D.
testis
Answer: C
5.
The ability of birds to fly depends on
A.
Their hollow hones only
B.
Their flight feathers only
C.
Their feathers covering their bodies
D.
Their hollow bones and flight feathers
E.
Their light bodies only
Answer: D
6.
The consequences of the greenhouse effect on humans include
I. flooding of coastal cities
II. desertification of fertile areas
III. increased number of storms
IV. increased use of fossil fuels
A.
I, II, III and IV
B.
II and III only
C.
I, II and III only
D.
I and II only
Answer: D
7.
An electric bulb is rated 0.5 A, 120 V. Determine the power produced when the bulb is turned on.
A.
60 kW
B.
60 W
C.
30 kW
D.
30 W
Answer: B
Electric Power Formula
Power = Current(I) x Potential Difference/Voltage(V)
P = IV
Current (I) = 0.5 A =
Potential Difference/Voltage(V) = 120V
Power = x 120 W = 60 W
8.
When a person jumps up, he/she is able to come down because of the
A.
pull of the earth's gravitational force.
B.
pull of the earth's magnetic force.
C.
resistance of the earth's atmosphere to the upward motion.
D.
pressure of the earth's atmosphere on the person.
Answer: A
9.
The housefly is an agent for the spread of
A.
cholera.
B.
malaria.
C.
measles.
D.
tuberculosis
Answer: A
10.
Which of the following body shapes facilitates movement in a fluid?
A.
Rectangular
B.
Spherical
C.
Streamline
D.
Triangular
Answer: C
11.
Brass is an alloy made up of
A.
Aluminium and zinc
B.
Copper and tin
C.
Copper and zinc
D.
Iron and carbon
E.
Steel and tin
Answer: C
12.
Which of the following diseases is contracted through infected wounds?
A.
Chicken pox
B.
Diphtheria
C.
Mumps
D.
Tetanus.
E.
Whooping cough.
Answer: D
13.
The organelle which occupies the largest portion of a plant cell is the
A.
chloroplast.
B.
mitochondrion.
C.
nucleus.
D.
vacuole.
Answer: D
14.
Brass is an alloy of
A.
iron and carbon
B.
zinc and copper
C.
iron and copper
D.
copper and tin
Answer: B
15.
The chemical symbol for iron is
A.
I
B.
K
C.
Fe
D.
Au
E.
Cl
Answer: C
16.
Steel is an alloy of iron and
A.
aluminium.
B.
carbon.
C.
silicon.
D.
gold.
Answer: B
17.
The shape of a child’s nose may resemble that of the mother due to
A.
heredity
B.
similarity
C.
reflection
D.
familiarity
E.
attraction
Answer: A
18.
Which of the following statements is not true about the wet season
A.
Bush fires are common
B.
Tree and weeds grow fast
C.
Small animals increase in number
D.
The weather is generally cool
E.
Food is in abundance
Answer: A
19.
At which positions S,R,Q and P on the lever in the diagram below must a force be applied to lift the load most easily?
A.
P
B.
Q
C.
R
D.
S
Answer: A
The mechanical advantage of a lever can be calculated as shown below:
The higher the mechanical advantage, the better the machine our work output.
From the formula you will realize that the longer the distance of the effort from the pivot, the higher the mechanical advantage will be since the distance from the load and pivot is fixed (constant).
The distance P will have the highest mechanical advantage, hence that is the best position to apply the force to lift the load.
20.
The type of teeth used for biting and cutting are the
A.
canines.
B.
incisors.
C.
molars.
D.
premolars.
Answer: B
Incisors
Incisors are the four front teeth in the centre of each jaw. Their cutting edges are broad and sharp like chisel. They are used for biting and cutting.
21.
Which of the following statements about acids are correct?
I. They turn red litmus paper blue
II. They can be classified as either organic or mineral acids
III. They can be neutralized by bases
A.
I and II only
B.
I and III only
C.
II and III only
D.
I, II and III
Answer: C
22.
Micro-organisms that cause disease are collectively called
A.
bacteria.
B.
infections.
C.
pathogens.
D.
viruses.
Answer: C
23.
The figure below shows the arrangement of parts of the soil when some soil sample was shaken with water in a glass cylinder and allowed to settle.
Use it to answer the question below.
The layer which does not have the ability to retain much water is
A.
N
B.
O
C.
P
D.
Q
Answer: D
24.
Lime juice taste sour because it is
A.
acidic.
B.
alkaline.
C.
basic.
D.
salty.
Answer: A
25.
A patient with symptoms of diarrhoea and vomiting may be suffering from
A.
cholera.
B.
dysentery.
C.
influenza.
D.
tuberculosis.
Answer: A
26.
The main waste products formed in plants are
A.
water, carbon dioxide and urea
B.
water, carbon dioxide and oxygen
C.
water, carbon dioxide and mineral salts
D.
water, ammonium compounds and oxygen
E.
water, ammonium compounds and carbon dioxide
Answer: D
27.
The device that uses an electromagnet in its operation is the
A.
electric bell.
B.
electric iron.
C.
radio.
D.
refrigerator.
E.
sewing machine.
Answer: A
Process of the working of an electric bell
1. The switch is pressed and current flows through the circuit.
2. The electromagnet is powered and generates a magnetic field that attracts the iron strip towards it.
3. The striker strikes the gong (bell).
4. When the striking arm strikes the gong, the contact is broken and the current stops flowing through the circuit.
5. This causes the electromagnet to lose its magnetic field.
6. The connected spring arm returns the striker to its original rest position.
7. The contact is restored and current flows through the circuit (provided the main switch is still pressed).
28.
The ion that causes hardness in water is
A.
CO32-.
B.
Mg2+.
C.
Na+.
D.
OH-.
Answer: B
Calcium (Ca2+) and magnesium (Mg2+) are the causes the hardness of water.
29.
In a first class lever, the load is placed
A.
on the effort
B.
between the effort arm and the pivot
C.
at one end of the load arm
D.
between the pivot and the load arm
E.
on the pivot
Answer: C
30.
The second stage in the life cycle of a mosquito is the
A.
egg
B.
imago
C.
larva
D.
pupa
Answer: C
31.
Rainfall is a result of
A.
low pressure.
B.
strong wind.
C.
cold wind.
D.
low humidity.
Answer: A
When the pressure is low, the air is free to rise into the atmosphere where it cools and condenses.
This condensation forms clouds made of water droplets and ice crystals around dust particles in the sky. Eventually the water vapor in the clouds condenses and falls as rain.
32.
The fifth planet from the sun in the solar system is
A.
Jupiter.
B.
Mars.
C.
Neptune.
D.
Venus.
Answer: A
33.
Excess carbohydrate in the human body is stored as
A.
amino acid.
B.
fatty acid.
C.
glycogen.
D.
glucose.
Answer: C
34.
Which of the following plants reproduce(s) vegetatively?
I. Banana
II. Mango
III. Ginger
A.
II only
B.
I and II only
C.
I and III only
D.
III only
Answer: C
Vegetative reproduction, any form of asexual reproduction occurring in plants in which a new plant grows from a fragment of the parent plant or grows from a specialized reproductive structure (such as a stolon, rhizome, tuber, corm, or bulb).
35.
The second stage in the life cycle of a mosquito is the
A.
egg.
B.
imago.
C.
larva.
D.
pupa.
Answer: C
36.
Farmers do not plant the stems of maize because the stems
A.
do not have buds.
B.
are difficult to obtain.
C.
dry up too quickly.
D.
do not contain food.
Answer: A
37.
Which of the following statements about bush fires is/are true?
I. They cause air pollution
II. They deplete vegetation cover
III. They contribute to global warming
A.
I only
B.
II only
C.
II and III only
D.
I, II and III
Answer: D
38.
How long does it take the moon to go completely round the earth?
A.
1 day
B.
28 days
C.
30 days
D.
365 days
Answer: B
39.
Which of the following factors has the greatest influence on vegetable crop production?
A.
Availability of labour
B.
Nearness to market
C.
Source of water
D.
Presence of pest
Answer: C
40.
Use the diagrams below to answer the question below
Which of the following statements is correct about the circuit diagrams above? The cells in diagram
A.
X are in series and the key is open.
B.
X are in parallel and the key is open.
C.
Y are in series and the key is closed.
D.
Y are in parallel and the key is closed.
Answer: A
THEORY QUESTIONS
1.
(a)
(i)
Give two differences between a vein and an artery.
(ii)
State two functions of red blood cells.
(iii)
Mention two diseases associated with the circulatory system.
(b)
(i)
Classify the following processes into a physical change and a chemical change:
Cooking of food;
Melting of candle;
Melting of ice;
Rusting of iron;
Dissolution of sugar in water;
Burning of wood into ash.
(ii)
Explain the basis of the classification in (b)(i).
(c)
(i)
State the laws of reflection.
(ii)
Draw a ray diagram of light incident at an angle of 40o on the surface of a plane mirror.
(a)
(i)
Differences between a vein and an artery
| Vein | Artery |
| Located close to the surface of the skin | Located deep in the muscles |
| Thin walled | Thick walled |
| Presence of valves | Absence of valves |
| Smaller in size | Bigger in size |
| Blood flows under low pressure/blood flows smoothly | Blood flows under high pressure/flows in pulses |
| Carries blood to the heart | Carries blood away from the heart |
| Carries blood with low oxygen/carries de-oxygenated blood | Carries blood with high oxygen/carries oxygenated blood |
| Has bigger lumen | Has smaller lumen |
| Less elastic wall | More elastic wall |
(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
(b)
(i)
| Physical Change | Chemical Change |
| Melting of candle | Cooking of food |
| Melting of ice | Rusting of iron |
| Dissolution of sugar in water | Burning of wood into ash |
(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
(c)
(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)
2.
a)
i)
Define photosynthesis.
ii)
Give two ways in which photosynthesis is important to animals.
b)
Name three sources of chemical energy.
c)
Describe how you would separate a mixture of sodium chloride and sand.
d)
Complete and balance the following chemical reaction:
CaCO3 + HCl →
e)
Two dry cells, a switch and a bulb are connected in series. Draw and label a circuit diagram of the arrangement.
a)
i)
Photosynthesis is a process whereby green plants containing chlorophyll manufacture food/carbohydrates/starch/glucose from carbon dioxide and water in the presence of sunlight.
ii)
Importance of photosynthesis to animals
1. Food/carbohydrates/starch/glucose produced provides energy for animals
2. Oxygen released is used for respiration
3. Accumulation of carbon dioxide is prevented since they are used by plants during photosynthesis
b)
Sources of chemical energy
1. Chemical reactions/Oxidation/Combustion
2. Food/carbohydrates/starch/glucose
3. Petroleum/Kerosene/Petrol/Diesel oil
4. Fossil fuels/firewood
5. Dry cell/generator/batteries/accumulator
6. Natural Gas
c)
Separation of a mixture of sodium chloride and sand
1. Add water to the mixture
2. Stir the mixture until the sodium chloride dissolves
3. Filter off the sand and evaporate the filtrate to obtain the sodium chloride
d)
CaCO3 + HCl → CaCl3 + H2O + CO2
e)
3.
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.
4.
a)
i)
What is fertilization
ii)
Describe briefly the processes that lead to fertilization in humans after mating.
b)
i)
Define the term density
ii)
Describe briefly how the density of a piece of stone could be determined
c)
i)
What is an element?
ii)
Classify each of the following substances as an element, compound or mixture: Water, air, potassium, alcohol, common salt, sugar
a)
i)
Fertilization is the fusion of the male and female sex cells to form a zygote.
ii)
The processes that lead to fertilization in humans after mating
1. The sperms move through the vagina, cervix and uterus to the fallopian tube
2. Only one of the millions of sperms succeeds to penetrate the membrane of the ovum
3. The nuclei of the sperm and ovum unit/fuse to form a zygote
b)
i)
Density of a substance is the mass per unit volume of the substance.
OR
Density =
ii)
Determination of the density of a stone
1. Measure/weigh the mass of stone by means of a beam/chemical balance as M g
2. Fill a large measuring cylinder with water to a suitable level and record the volume as V1 cm3
3. Tie the stone with thread and gently lower it into the water in the measuring cylinder and record the new volume as V2 cm3
The density of the stone is then calculated as follows:
Volume of stone = V2 cm3 - V1 cm3
Mass of stone = M g
Density =
Density of the stone =
c)
i)
An element is a substance that cannot be broken down/split into simpler substances by any known chemical means.
ii)
| Element | Compound | Mixture |
| Potassium |
Water
|
Air |
5.
(a)
(i)
What is a disease vector?
(ii)
Mention two methods of controlling each of the following types of pests of farm animals:
(α)
ectoparasites;
(β)
endoparasites.
(b)
(i)
State two symptoms of nitrogen deficiency in a tomato plant.
(ii)
Describe side dressing as a method of fertilizer application.
(c)
(i)
Define power
(ii)
State the S.I unit of power
(d)
Draw the electronic structure of potassium
[Atomic number of potassium = 19]
(a)
(i)
Disease vector is an organism that carries and transmit a disease causing organism.
(ii)
(α)
Methods of controlling ectoparasites
1. Rotational grazing
2. Dusting with powdered pesticides
3. Footbath
4. Spraying with appropriate chemicals
5. Dipping with the recommended/appropriate chemicals
6. Controlled burning of pasture
7. Correct stocking rate to avoid overcrowding
8. Washing with acaricides
9. Oral medication
10. Handpicking
11. Vaccination
(β)
Methods of controlling endoparasites
1. Deworming animals with recommended/appropriate chemicals
2. Grazing after sunrise
3. Maintenance of good sanitation/regular change of litter
4. Rotational grazing
5. Vaccination
(b)
(i)
Symptoms of nitrogen deficiency in a tomato plant
1. Yellowing of leaves/chlorosis
2. Stunted growth
3. Weak and slender stems
(ii)
Side dressing is the application of fertilizer at one or both sides of crops on the surface of the soil while the crops are growing.
(c)
(i)
Power is the time rate of doing work
OR
Power is the rate of energy dissipation/rate of using energy
OR
Power =
OR
Power =
(ii)
The S.I unit of power is watt (W)
(d)
Electronic structure of potassium
Note: 19 = 2, 8, 8, 1
6.
(a)
(i)
Explain heredity
(ii)
Give two examples of heredity characters.
(b)
Explain whether each of the following processes is a chemical change or a physical change:
(i)
Rusting;
(ii)
Burning;
(iii)
Filtration;
(iv)
Expansion of copper.
(c)
(i)
What is a simple machine?
(ii)
Name two types of simple machines.
(iii)
Explain why the efficiency of a machine cannot be equal to 100%.
(a)
(i)
Heredity is the process in which offsprings acquire characteristics from their parents through the genes they receive from them.
(ii)
Examples of heredity characters
1. Weight
2. Intelligence
3. Colour of the skin
4. Ability to roll the tongue
5. Temperature
6. Height/stature of an individual
7. Colour of eyes
8. Colour of hair
9. Blood group
10. Shape of face/nose/head/eye
11. Haemophilia
12. Albinism
13. Sex
(b)
Chemical change and physical change:
(i)
Rusting
Chemical change because a new substance (rust) different from iron is formed.
(ii)
Burning
Chemical change because the ash cannot be turned back easily into the original material.
(iii)
Filtration
Physical change because the components can be gotten easily.
(iv)
Expansion of copper
Physical change because the original shape of the copper can be gotten easily.
(c)
(i)
Simple machine is a device that can be used to make work easier or faster.
OR
Simple machine is a device on which a force/an effort is applied at one point to overcome another force/load at another point.
OR
Simple machine is a device which enables a small force (effort) to overcome a large force (load).
(ii)
Types of simple machines
1. Levers
2. Inclined plane
3. Pulley
4. Wheel and axle
5. Screw
6. Wedge
7. Gears
(iii)
Why the efficiency of a machine cannot be equal to 100%
Part of the work put in the machine to overcome the load is used to overcome friction/weight of machine parts/force of gravity/air resistance so that the work output is always less than the work input.