BECE 2009 Integrated Science Past Question Paper Two
(a) In an experiment, four nails 1, 2, 3 and 4 are fixed with candle wax onto a metal bar and one end
of the bar is heated by means of boiling water as shown in the diagram below
A, B, C, D are thermometers inserted in holes along the bar to measure the temperatures at the
various points.
(i) What is the temperature of the boiling water?
(ii) State the observations that will be made about nails 1, 2, 3 and 4
(iii) State the observations that will be made about the temperatures recorded by thermometers A, B, C and D.
(iv) What mode of heat transfer is demonstrated in the experiment
(v) State one effect of heat that is associated with the experiment
(vi) State the aim of the experiment
1(b) In an experiment, a student took three iron nails and cleaned their surfaces dry and placed them
in three separate test tubes in set-ups A, B and C as shown in the diagram.
After three days the nail in set-up A was found to have rusted while the nails in set-ups B and C did not.
Answer the following questions:
(i) Why was the water in set-up B boiled?
(ii) Explain the function of the oil on top of the water in set-up B.
(iii) State the purpose of the rubber stopper in set-up C
(iv) Why did the nail in set-up A rust?
(v) Suggest an aim for the experiment.
(vi) From the experiment, explain why oil or grease is applied on the surface of a metal to prevent
rusting.
1(c) In an experiment the following activities were carried out on two green leaves A and B.
Leaf A was from a plant placed in the sunlight for some time while leaf B was from a plant placed in a dark cupboard for 24 hours.
Activity | |
I. | Leaves dipped in boiling water for 1 minute |
II. | Leaves dipped in warm alcohol |
III. | Leaves washed in cold water |
IV. | Leaves dipped into iodine solution |
After dipping in the iodine solution, it was observed that leaf A changed colour while leaf B did not change colour.
Answer the following questions:
(i) Explain why each of the activities I, II, III and IV was carried out.
(ii) State the colour change of leaf A
(iii) Explain why leaf A changed colour but leaf B did not.
(iv) Suggest an aim for the experiment.
1.(a) (i) Temperature = 100°C or 212°F or 373K
(ii) Observations (Nails)
Nails 1, 2, 3 and 4 will drop off one after the other
– Nail 1 drops first, nail 2 second, nail 3 third and nail 4fourth
(iii) Observations (Thermometers)
The readings of Thermometers A, B, C and D will increase progressively till they reach
100°C
– Thermometer A reaches 100°C first, B second, C third and D fourth
(iv) Mode of heat transfer
– Conduction
(v) Effects of heat
? Causes increase in temperature (as shown by the thermometer readings)
? Causes change in state (candle wax melts – changes from solid to liquid)
(vi) Aim of experiment
? To show that metals are good conductors of heat
? To show that heat travels through metals
(i) Why water in set-up B was boiled
To remove dissolved air / oxygen from the water
(ii) The function of the oil on top of the water in set-up B
To prevent air (hence, oxygen) from entering / getting dissolved in the water
(iii) The purpose of the rubber stopper in set-up C
To prevent water particles or vapour or moisture from entering and contacting the nail
(v) Aim for the experiment
? To show that moisture/ water and oxygen/ air are necessary for rusting to occur.
(vi) Why grease is applied on metals to prevent rusting
To prevent moisture and air, which contains oxygen, from getting into contact with the metal, since metals containing iron will rust in the presence of air and moisture.
(c) (i) Why each activity was carried out
I – to kill the plant cells or stop the process of photosynthesis
II – remove the green pigment (chlorophyll)
III – to wash away the alcohol and soften the leaf
IV – to test for starch in the leaf
(ii) Colour change of leaf A
From cream / pale yellow / light brown to blue-black
(iii) The blue-black colouration indicates the presence of starch, which means that photosynthesis occurred in leaf A to produce starch.
Leaf B did not change in colour because photosynthesis did not occur, and hence, no starch was produced.
(a) Explain each of the following observations in nature:
(i) In the depths of the ocean where it is always dark, there are no green plants.
(ii) On an island where there are no insects and birds, the pawpaw plant produces only flowers but
no fruits
(b) Describe how soil is formed.
(c) (i) State the laws of reflection
(ii) Draw a labelled diagram to show the reflection of light on a plane mirror
(a) (i) Reasons for no green plants in the dark ocean depths
No light reaches there, hence no photosynthesis takes place.
(ii) Reasons for no fruits on pawpaw plant, where there are no insects and birds
Since there are no agents of pollination, no pollination takes place; hence, no fertilization
takes place. As a result, no fruits are produced.
(b) How soil is formed:
Soil is formed from the disintegration/ breakdown/ weathering of rocks. The broken down rock particles combine with water,
decayed organic matter, air and micro organisms to form soil
(c) (i) Laws of reflection
? The angle of incidence is equal to the angle of reflection
? The incident ray, the reflected ray and the normal, at the point of incidence, all lie in the same plane
(ii) Labelled diagram
i = angle of incidence,
r = angle of reflection
(a) A child is found not to be able to see at night
(i) What deficiency disease may the child be suffering from?
(ii) What food nutrient is the child lacking?
(iii) List two sources of food substances that can provide the nutrient the child lacks.
3(b) (i) What is an atom?
(ii) Name the components of an atom which determines each of the following quantities.
(a) mass of an atom
(ß) charge of an atom
(iii) Why is an atom electrically neutral?
3(c) (i) What is friction?
(ii) Give two bad effects of friction.
(iii) Give two situations where friction is an advantage
3. (a) (i) Deficiency disease: Night blindness
(ii) Food nutrient: Vitamin A
(iii) Food sources: Milk, butter, cheese, egg yolk, liver, palm oil, tomatoes, carrots, lettuce, cod-liver oil,
(b) (i) Atom
• The smallest particle of a substance that can take part in a chemical reaction
• The smallest portion into which an element can be divided and still retain its properties
(ii) Components of atom that determine
(a) mass of atom: protons and neutrons
(ß) charge of atom: protons and electrons
(iii) Why an atom is electrically neutral:
The numbers of protons and electrons are equal. The positively charged protons neutralize the negatively charged electrons, hence, making the atom electrically neutral.
(c) (i) Friction is
The force that opposes the relative sliding motion of two bodies in contact
Or:
The resistance encountered by an object moving relative to another object with which it is
in contact
(ii) Bad effects of friction
? Reduces the efficiency of machines
? Causes wear and tear
? Causes loss of energy through heat generation
? Slows down sliding motion of a body
(iii) Situations where friction is an advantage
? Enables walking, running, etc without slipping
? Enables vehicles to brake effectively
? Enables birds to perch on trees without falling
? Enable wheels to roll on a surface
? Enables our hands to hold items
(a) (i) Explain heredity
(ii) Give two examples of heredity characters
4(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
4(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%
4.(a) (i) Heredity
The passing on of genetic factors from parents to children through genes:
Or:
The transfer of genetically controlled characteristics from one generation to the next in living organisms
(ii) Examples: Intelligence, shape of nose, height, colour of eyes, etc
(b) Explanation of whether chemical or physical change:
(i) Rusting – Chemical change; because a new substance is formed and the change is irreversible
(ii) Burning – Chemical change; because a new substance is formed and the change is irreversible
(iii) Filtration – Physical change; because no new substance is formed and the change is reversible
(c) (i) Expansion of copper – Physical change; because no new substance is formed and the
change is reversible
A simple machine
A mechanical device that makes work easier and/ or faster
(ii) Types of simple machines
Inclined plane, wheel and axle, lever and pulley
(iii) Why the efficiency cannot be 100%
Part of the energy input is used to overcome friction and part also expended as heat
(a) Study the organisms listed below: Earthworm;
Sheep; Cassava plant; Grasshopper; Man; Hen.
Draw a food chain using four of the organisms
(b) (i) Name four types of forces apart from friction.
(ii) Give three effects of a force
5(c) A certain pupil in a classroom can see clearly on the blackboard only when he sits at the front.
(i) State the eye defect the child is suffering from.
(ii) Explain why the child is unable to see when he is far from the blackboard.
(iii) How can the defect be corrected?
(a) (i) What is respiration?
(ii) Name the types of respiration that occur in humans
(b) List three ways of maintaining soil fertility
(c) (i) Write the systematic name of each of the following chemical compounds:
(a) FeS;
(ß) SO2
(?) CO2
(ii) Give one reason why copper, silver and gold are mostly used in making ornaments and jewellery.
(d) (i) What is a fuse?
(ii) Explain why a fuse is used in an electrical circuit.
5. (a) Food chain
Cassava plant ? grasshopper ? hen ? man
Or:
Cassava plant ? earthworm ? hen ? man
(b) (i) Types of forces apart from friction:
Gravitational, tensional, centripetal, centrifugal, magnetic, electrostatic, upthrust, cohesive, adhesive
(ii) Effects of a force
• Can cause a moving body to come to rest (stop moving)
• Can cause a body at rest to move
• Can cause a moving body to accelerate
• Can cause a moving body to decelerate
• Can change the direction of a moving body
• Can change the shape of a body
(c) (i) The eye defect: shortsightedness or myopia
(ii) Explanation
Light rays from a distant object are focused in front of the retina, due to the eye lens being thicker than normal or eyeball being too long. Hence the brain does not receive the correct information for interpretation and so the child is unable to
see.
(iii) How the defect can be corrected: By the use of a concave or diverging lens
(a) (i) What is the difference between unicellular organism and multicellular organism
(ii) State two reasons why vegetable crops are important to humans
(b) (i) State two elements of climate
(ii) What is the difference between climate and weather?
(c) Mention three advantages of staking in crop production
(d) Explain each of the following processes:
(i) corrosion;
(ii) sublimation
6. (a) (i)
Unicellular organism | Multicellular organism |
organism is made up of only one cell | organism is made up of more than one cell |
(ii) Why vegetable crops are important to humans
? Good source of vitamins
? Good source of mineral salts
? Make food tasty
? They have high fibre content
(b) (i) Elements of climate
? Rain
? Temperature
? Humidity
? Sunshine
? Atmospheric pressure
? Cloud
? Wind
(ii) Difference
Climate | Weather |
atmospheric condition of a place over a long period of time | atmospheric condition of a place over a short period of time |
(c) Advantages of staking in crop production
? Keeps fruits clean
? Enables easy weeding
? Enables easy harvesting
? Prevents early spoilage of fruits
? Keeps plant from falling during storms
? Keeps plant from falling under the weight of mature fruits
(d) (i) Corrosion explanation
A process by which a substance, especially a metal, is destroyed progressively by
chemical action.
Example: the rusting of iron
(ii) Sublimation explanation
A process in which a substance is converted directly from a solid to a gas or from a gas to
a solid without passing through the liquid state
Example: the conversion of naphthalene ball (camphor) from solid to gas directly
End Of Paper
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