Science Questions and Answers - Class 8 Opener Exams Term 1 2023 Set 6

QUESTIONS

1. Which of the following sets of teeth in human beings is used for chewing?
   1. Pre-molars and molars.
   2. Canines and incisors.
   3. Incisors and premolars.
   4. Canines and molars.
2. The following activities take place during breathing out except
   1. ribs move downwards and inwards.
   2. volume of the chest decreases.
   3. diaphragm flattens.
   4. lungs shrink.
3. Which one of the following statements about the circulation of blood in human beings is correct? The
   1.  auricles receive blood from the body.
   2. walls of ventricles are thicker than the walls of the auricles.
   3. the valves in the heart and veins prevent the flow of blood.
   4. the pulmonary vein carries oxygenated blood from the heart to the left ventricle.
4. Which of the following vaccines is administered when an infant is six weeks old?
   1. First dose of BCG.
   2. First dose of diphtheria.
   3. Second dose of polio.
   4. Second dose of BCG
5. Which of the following drugs are not prohibited in Kenya?
   1. Mandrax, Bhang, Cocaine.
   2. Khat, heroine, cobbler's glue.
   3. Tobacco, Khat, alcohol.
   4. Alcohol, miraa, cocaine.
6. The diagram below shows a weather instrument.
   
   A part of the rainguage is buried underground in order to
   1. collet more rainwater.
   2. reduce the chances of evaporation.
   3. make correct readings.
   4. avoid rusting.
7. Which one of the following phases of the moon is not clearly visible from the earth?
   1. Gibbous.
   2. New moon.
   3. First quarter.
   4. Full moon.
8. Which one of the following water borne diseases is likely to lead to severe dehydration?
   1. Typhoid.
   2. Bilharzia.
   3. Cholera.
   4. Malaria.
9. Which one of the following practices does not help to conserve water?
   1. Mulching.
   2. Re-using.
   3. Recycling dirty water.
   4. Covering stagnant water with oil to kill mosquito larvae.
10. Which of the following consists only of natural sources of light?
    1. Stars, planets, moon.
    2. Firefly, glow worms, stars.
    3. Lamps, candle, fire.
    4. Moon, firefly, sun.
11. The following are ways of lighting a house except
    1. fixing windows.
    2. using translucent roofs.
    3. using electric lamps.
    4. use of solar heaters.
12. Which one of the following is not a safety precaution when handling current electricity?
    1. Do not overload sockets.
    2. Repair electrical appliances while unplugged.
    3. Buildings under electric lines should not be too tall.
    4. Avoid touching sockets with wet hands.
13. Grade 6 pupils carried the following items for a practical lesson:
    1. Water.
    2. Basin.
    3. White manilla paper.
    4. Mirror.
       The aspect of light they were likely to investigate was
       1. dispersion of light.
       2. reflection of light.
       3. refraction of light.
       4. how light travels.
14. The chart below shows a simple classification of plants.
    
    The plants representing Q and R respectively are
    1. maize and puffball.
    2. moss and oxalis.
    3. cactus and algae.
    4. mushroom and moulds.
15. In which of the following parts of the breathing system does the exchange of gases take place?
    1. Nose.
    2. Trachea.
    3. Lungs
    4. Bronchus.
16. Which one of the following is not a source of current electricity?
    1. Dry cells.
    2. Water fall.
    3. Dynamo.
    4. Solar panel.
17. Which one of the following is an opaque material?
    1. Frosted glass.
    2. Car windscreen
    3. Milk.
    4. Skylight.
18. Which one of the following is the main reason for using organic manure? In order to
    1. provide plant nutrients in the right amount.
    2. provide specific nutrients.
    3. release plant nutrients to the soil immediately.
    4. improve the ability of the soil to hold water.
19. Which one of the following objects can sink or float on water depending on its shape?
    1. Wood.
    2. Piece of charcoal.
    3. Razor blade.
    4. Stone.
20. The pie chart shown below shows approximate percentages of air.
    
    Which gases are used in electric bulbs and making plant food?
    1. S and T
    2. R and S
    3. Q and T
    4. R and Q
21. Which one of the following statements is correct about HIV/AIDS?
    1. During window stage, a person may test positive.
    2. During incubation, a person may test positive with no signs.
    3. A person develops AIDS at symptomatic stage.
    4. Some herbs are capable of treating HIV.
22. Through which of the following processes does a liquid change to a solid?
    1. Melting.
    2. Evaporation.
    3. Condensation.
    4. Freezing.
23. Which one of the following sets of plants has similar root systems?
    1. Maize, sorghum, peas.
    2. Grass, rice, millet.
    3. Wheat, maize, kales.
    4. Cowpeas, rice, beans
24. Which one of the following is not true about all states of matter? Matter
    1. occupies space.
    2. has a definite shape.
    3. has mass.
    4. contracts when cooled.
25. Which pair of methods of separating mixtures below is suitable for separating solid mixtures only?
    1. Winnowing and picking.
    2. Dissolving and using a magnet.
    3. Filtering and sieving.
    4. Evaporation and decantation.
26. Which one of the following small animals help in soil aeration?
    1. Moles and ants.
    2. Houseflies and bees.
    3. Termites and butterflies.
    4. Earthworms and grasshoppers.
27. Which of the following materials can be used to complete a circuit?
    1. Cellotape.
    2. Wollen thread.
    3. Biro pen casing.
    4. Pencil lead.
28. The diagram below shows a block of wood being pushed along a surface towards point X.
    
    Which one of the arrows represents the direction of the force of friction?
    1. J
    2. K
    3. L
    4. M
29. Which one of the following animals lays eggs, breathes by lungs and has a consiant body temperature?
    1. Frog.
    2. Tortoise,
    3. Hen.
    4. Seal.
30. Which one of the following fodder crops contains proteins?
    1. Kales.
    2. Luceme.
    3. Napier grass.
    4. Millet.
31. Which one of the following is a disadvantage of stall feeding as a system of rearing dairy cattle?
    1. Animals occupy a small space.
    2. Manure accumulates fast.
    3. There is little feed wastage.
    4. Too much labour is required.
32. Which of the following pair of liquids below will not form a uniform solution?
    1. Water and kerusene.
    2. Water and milk.
    3. Methylated spirit and milk.
    4. Kerosene and cooking oil.
33. The diagram below shows a simple machine.
    
    The fulcrum is labelled
    1. J
    2. K
    3. L
    4. M
34. Below are some activities that pollute the environment:
    1. Burning tyres.
    2. Using diesel driven generators.
    3. Spraying farm chemicals.
    4. Oll spillage.
       Which pair of activities pollutes water
       1. i and ii
       2. i and iii
       3. ii and iv
       4. iii and iv
35. Which one of the following is a description of black jack? It
    1. has seeds which have hooks.
    2. has a bad smell.
    3. has succulent stems and a fibrous root system.
    4. has fruits with thorns.
36. Which of the following is the most suitable foodstuff for a child suffering from kwashiorkor?
    1. Fish, carrot, oranges.
    2. Bert, milk, watermelon.
    3. Green vegetables, milk, chicken.
    4. Beef, cowpeas. liver.
37. The diagram below shows a bean seed.
    
    Water and air enter the seed through
    1. G
    2. H
    3. J
    4. K
38. Which one of the following parasites does not attack the lungs?
    1. Flukes.
    2. Roundworms.
    3. Hookworms.
    4. Lungs.
39. The texture of a soil type is determined by the
    1. size of its particles.
    2. amount of water in it.
    3. amount of humus in it.
    4. amount of mineral particles in it.
40. The purpose of using rollers to move a. load is to
    1. increase the force required to push the load.
    2. reduce the force that hinders the movement of the load.
    3. make the load lighter.
    4. control the direction of the movement of the load.
41. Which one of the following is not a practice for maintaining simple tools?
    1. Oiling and greasing
    2. Using them for the right purpose.
    3. Sharpening cutting edges.
    4. Storing in a safe place.
42. Which one of the following groups of materials consists only of non-magnetic materials?
    1. Nickel, aluminium, copper.
    2. Plastic, copper, aluminium.
    3. Paper, iron, glass.
    4. Staples, chalk, iron.
43. Which one of the following does not allow sound to pass through?
    1. Air.
    2. Water.
    3. Vacuum.
    4. Wood.
44. Which one of the following pairs of foodstuffs is preserved by smoking, salting and drying?
    1. Meat and mushrooms.
    2. Beans and fish.
    3. Mushroom and beans.
    4. Beef and fish.
45. Which one of the following weeds has green purple leaves?
    1. Pig weed.
    2. Mexican marigold.
    3. Oxalis.
    4. Wondering jew.
46. A millipede protects itself by
    1. coiling.
    2. stinging.
    3. withdrawing into the shell.
    4. running away.
47. Which one of the following diseases can be prevented by drawing away stagnant water?
    1. Cholera and malaria.
    2. Malaria and bilharzia.
    3. Typhoid and bilharzia.
    4. Typhoid and cholera.
48. Which of the following shows a pair of major components of the environment?
    1. Plants and light.
    2. Water and soil.
    3. Animals and heat.
    4. Air and buildings.
49. Below are changes that takes place during adolescence:
    1. Hips broaden
    2. Beards
    3. Onset of menses
    4. Wet dreams
    5. Change of voice
       Which pair of changes take place in boys only?
       1. i and iii
       2. iii and iv
       3. iv and v
       4. ii and iii
50. Which one of the following methods of grazing is suitable in a small piece of land?
    1. Stall feeding.
    2. Paddocking.
    3. Strip grazing.
    4. Herding.

MARKING SCHEME