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2012 WASSCE (November) Integrated Science Practicals
1. Figure 1 (a) is an illustration of an electric circuit used to investigate Ohm’s Law.
Figure 1a [diagram required]
Figure 1 (b) shows five ammeter readings [formula required] while figure 1 (c) also shows the corresponding voltmeter readings [formula required]
Study the figures carefully and answer the questions that follow.
Figure 1b [diagram required]
Figure 1c [diagram required]
a) Read and record in a tabular form the ammeter readings [formula required] and the corresponding voltmeter readings [formula required]
b) Plot a graph with V on the vertical axis and I on the horizontal axis.
c) i) Determine the slop of the graph.
ii) State the significance of the slope determined in (c) (i).
V / V |0.4 |0.8 |1.4 |2.2 |3.4
I / A |0.2 |0.4 |0.7 |1.1 |1.7
b) [Diagram required]
c) i) Slope [formula required]
ii) The slope represent resistance
2. Figure 2 is an illustration of organisms of agricultural importance.
Study the figure carefully answer the questions that follows.
A [Diagram required]
B [Diagram required]
C [Diagram required]
D [Diagram required]
a) Identify each of the organisms A, B, C and D.
b) i) Name one host of organism A.
ii) State two effects of organism A on its host.
iii) State three ways of controlling organism A
c) Name two crops that are attacked by organism D.
d) State three ways in which organism B improves soil fertility.
a) A – Tick
B – Earthworm
C – Grasshopper
D – Centipede
b) i) Host of organism A
– Fowl or bird
ii) Effects of organism A on its host
– Sucks blood of its host or causes anaemia or sucks nutrients or host grows lean.
– Damages the skin of its host or affects the quality of the host’s skin.
– Causes injuries or wounds on its host.
– Acts as a vector of diseases or infects with pathogens or causes death or deviates from normal healthy nature.
– Causes irritation or restlessness or itchiness
– Causes deformity or stunted growth.
iii) Ways of controlling organism A
– Changing the animal beddings regularly.
– Regular dipping of animals or spraying animals with a caricide solution or with insecticide spray or dusting or pesticide or disinfectants.
– Keeping animal surroundings clean or regular weeding or good sanitation.
– Practice rational grazing or pad locking.
– Isolation of new stocks to ensure that they are free from infection.
– Hand-pick ticks from the body of the host.
– Keep grass or weed cut short.
– Give the host appropriate drug through water or drenching.
– Seal entry points used by rodents, squirrels etc to the house.
c) Ways in which organism B improves soil fertility
– Their burrowing activities create holes or spaces in the soil which improve soil aeration.
– Dead and decaying soil organisms increase the organic matter or humus in the soil.
– Assists in the decomposition or disintegration of organic matter leading to release of nutrients to the soil.
– Their activities assist in the mixing of soil with organic matter or they improve nutrient recycling in the soil or they improve soil texture.
– Creates holes in the soil to improve drainage.
– Improves soil structure.
3. a)State two safety precaution each to be taken when performing each of the following activities in the laboratory:
i) diluting concentrated sulphuric acid with water;
ii) handling poisonous chemicals;
iii) lighting a Bunsen burner.
b) With the aid of diagrams, describe briefly an experiment you would perform in the school laboratory to show that water is a necessary to show that water is a necessary condition for rusting of iron.
a) i) Diluting concentrated sulphuric acid
– The acid must be added to the water.
– Stir constantly.
– The acid should be added slowly to the water’
– Any spill of the acid on the body must be washed quickly with plenty of water.
– Wearing protective clothing or spectacles or goggles.
– Wear nose mask.
ii) Handling of poisonous chemicals
– Do not smell chemicals.
– Do not taste chemicals or eat chemicals or inject chemicals.
– Chemicals should be kept in fume chamber.
– Wear nose or gas mask or protective clothing.
– Ensure enough ventilation.
– Keep chemicals away from heat.
– Wash body with water quickly.
– Use spatula to pick chemicals.
– Avoid contact of chemicals to the skin.
iii) Lighting a Bunsen burner
– Light the match to the nozzle of the Bunsen burner first followed by opening of the tap of the gas source.
– Inspect hose for cracks or holes or leaks.
– Flammable materials should be set away or kept at a distance.
A – [Diagram required] B – [Diagram required] C – [Diagram required]
– Take two test tubes and label them separately as test tube A and test tube B.
– Into test tube A place some quantity of anhydrous calcium chloride or drying agent or oil.
– Seal it with plug to dry the air inside.
– Place some quantity of cotton wool on top of the calcium chloride.
– Put a few iron nails on top of the cotton wool in the test tube.
– Cover the test tube with the seal.
– Leave it for a few days or leave it for 3 -4 days .
– Put some water into test tube B.
– Place few iron nails into test tube.
– Leave it open for a few days or 3 -4 days or for long time.
– At the end of the experiment it would be observed that the iron in the test tube B rusted or the iron was covered with reddish brown layer.
– Iron nails in test tube A will not rust or have no reddish brown layer.
It can be deduced that water is a necessary condition for rusting of iron.
4. Figure 3 illustrates bones of the appendicular skeleton in mammals.
Study the figure carefully and answer the questions that follow.
A – [Diagram required]
B – [Diagram required]
C – [Diagram required]
a) Identity each of the bones A, B, and C.
b) Name each of the parts labelled I, II, III, IV, V, VI, VII and VIII.
c) State the location in the mammalian body where each of the bones A, B, and C is found.
d) State one observable characteristic feature each of bones A, B, and C.
e) Name the type of joint in a mammalian body formed by;
i) bones A and C;
ii) bones B and C.
a)A – Scapula or shoulder blade.
B – Radius-ulna or lower arm bone or fore arm bone.
C – Humerus or upper arm bone.
b)I – Glenoid cavity
II – Metacronium process.
III – Olecranon process
IV – Sigmoid notch
V – Radius or radical bone
VI – Ulna
VII – Shaft
VIII – Trochlea
c)A – shoulder
B – lower arm or fore arm
C -upper arm
d) Bone A
– It is triangular in shape.
– It has a broad blade.
– Presence of the glenoid cavity (into which the head of humerus fits) or metachromium process or coracoids process or acromium process or ridge flat surface.
– It is made of two long bones or radius and ulna.
– The ulna is slightly longer than the radius.
– Presence of the sigmoid notch (which articulates with the troclea of the humerus) or olecranon process.
– It is long bone.
– It has a rounded head (which fits into the glenoid cavity of the scapula).
– Presence of the trochlea (which fits into the sigmoid notch of the ulna) or (deltoid) ridge or shaft.
c) i) Ball and socket joint
ii) Hinge joint