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THEORY QUESTIONS

WAEC SYLLABUS

1. A group of closely related organisms capable of interbreeding to produce fertile offspring are known as members of a

A. kingdom.

B. class.

C. family.

D. species.

2. Viruses are economically important because they

A. Do not have cell structures,

B. Can only reproduce inside living cells.

C. Cause diseases in plants and animals.

D. Exist as crystals outside living cells.

3. A beaker of pond water containing few specimens of Euglena was placed in a dark room for two weeks. At the end of this period, the specimens of Euglena were still alive because they were

A. Able to carry out holozoic nutrition.

B. Able to carry out photosynthesis using carbon dioxide in the pond water.

C. Better adapted to life in darkness than to life in light.

D. not overcrowded.

4. The cytoplasm of the cell is considered a very important component because it

A. Regulates the amount of energy in the cell.

B. Suspends all cell organelles.

C. Is the outermost part of the cell.

D. Is solely responsible for cell division.

Use the diagram below to answer questions 5 to 7.

ANSWERS

6. The experiment above is used to demonstrate the process of

A. Transpiration.

B. Water culture.

C. Diffusion.

D. Osmosis.

7. In plant cells the role of the membrane is played by the

A. Nucleolus.

B. Cellwall

C. Cytoplasm.

D. Mitochondrion.

8. Red blood cells were found to have burst open after being placed in distilled water for an hour. This phenomenon is known as

A. Plasmolysis

B. Diffusion

C. Haemolysis.

D. Wilting.

9. The overall reaction in glycolysis can be summarised as

A. C6H12O6 -> C3H4O3 + 4H + ATP

B. C6H12O6 -> 2C3H4O3 + 4H + 2ATP

C. C6H12O6 -> 2C3H4O3 + 4H + 2ACP

D. C6H12O6 -> 2C3H4O3 + 4H + 2ADP

10. The curvature movement of plants in response to the stimulus of water is called

A. Hydrotropism

B. Geotropism.

C. Phototropism

D. Thigmotropism

ANSWERS

11. Two organelles directly involved in mitotic cell division are.

A. Nucleus and mitochondrion.

B. Ribosome and nucleus.

C. Centriole and golgi apparatus.

D. Nucleus and centriole.

12. The following statements about mitotic cell division are

A. It occurs only in young cells.

B. It occurs in somatic cells.

C. The chromosome number of the daughter cell is the same as that of the parent.

D. The genetic composition of the mother cell is the same as that of the daughter cell.

13. The longest bone in the body is the

A. Humerus.

B. Femur.

C. Scapula.

D. Muscle

14. Which of the following structures is not a skeletal material?

A. Chitin

B. Cartilage

C. Bone

D. Muscle

15. The reason why the flow of blood through the capillaries is very slow is

A. Because the walls of capillaries are very thin,

B. To avoid high blood pressure.

C. To ensure that the individual does not get dizzy.

D. To allow adequate time for exchange of materials,

ANSWERS

16. Which of the following features is not characteristic of arteries? Arteries

A. Possess valves at intervals throughout their length.

B. Have thick, muscular and elastic walls.

C. Carry blood away from the heart.

D. transport oxygenated blood with the exception of the pulmonary artery.

17. A group of rats placed in an air-tight box for some hours died because they

A. Breathed in air containing nitrogen.

B. Produced carbon dioxide.

C. Ran short of energy.

D. Used up the available oxygen.

18. Which of the following organisms have kidney as their excretory organ?

A. Fishes, amphibians, birds, man

B. Fishes, amphibians, annelids, insects

C. Fishes, reptiles, birds, tapeworms

D. Fishes, protozoans, amphibians, man

The graph in Fig. 1 below show the results of a laboratory investigation which measured the body temperatures of a lizard and a bird under changing artificial conditions. Use it to answer-questions 19 and 20.

19. Which of the statements below is valid?

A. The bird's blood was always warmer than that of the Iizard.

B. The body temperature of the bird varied less than that lizard during changes in environmental temperature.

C. The body temperature of the bird remained constant despite changes in environmental temperature.

D. The body temperature of the lizard was always close to that of the environmental temperature.

20 What physiological term can be used to describe the regulation of the body temperature of the lizard?

A. Homeostasis

B. Homoifhermy

C. Poikiloti

D. Osmoregulation

ANSWERS

21. The reason why hospitals use saline solutions as drip instead of water is

A. Because salt is a preservative.

B. To prevent contamination of the body.

C. To maintain the composition of body fluids.

D.

22. The part of the ear which i sound vibrations is the

A. Cochlea.

B. Ampulla.

C. Tynpanum.

D. Malleus.

23. Spectacles with convex lenses correct long-sightedness by

A. Converging the light rays before they enter the eye.

B. Diverging the light rays before they enter the eye.

C. Reducing light intensity before i enters the eye.

D. Increasing light intensity before i enters the eye.

24. A seed of a flowering plant can best be described as

A. Radicle and plumule.

B. The developed ovule.

C. The embryo and endosperm.

D. Developed ovary.

25. Which of the following processes removes carbon from the atmosphere?

A. Putrefaction

B. Photosynthesis

C. Volcanic eruption

D. Burning of fuels

ANSWERS

26. Which of the following cycles involves the process of precipitation and transpiration?

A. Water cycle

B. Carbon cycle

C. Nitrogen cycle

D. Oxygen cycle

27. The mesophyll layer of a leaf consists of

A. Wax and cutin.

B. Cells with lignified walls.

C. Irregularly shaped collenchyma cells.

D. Photosynthetic parenchyma cells.

28. Which of the following treatments would increase the rate of transpiration in a potted plant?

A. Placing it in a cold room

B. Placing it under a fan in a room

C. Putting it in a cupboard

D. Smearing grease on the lower surface of the leaves

29. Pepsin is secreted as an inactive precursor called pepsinogen because

A. Pepsin as an enzyme is quickly destroyed by the alkaline food from the mouth.

B. All digestive enzymes pass through a precursor stage.

C. Pepsin is a proteolytic enzyme and might attack the stomach tissues.

D. pepsin is not required in large quantities.

30. An organism whose source of carbon is inorganic is likely to be a/an

A. Heterotrophic organism.

B. Autotrophic organism.

C. Symbiotic organism.

D. Parasitic organism.

ANSWERS

31. Which of the following organisms is an endoparasite?

A. Mice

B. Mosquito

C. Ascaris

D. Dodder

32. Which of the following statements about ecosystems is false?

A. All the energy entering the ecosystem is passed on to decomposers.

B. The primary producers provide energy for herbivores and carnivores.

C. Ecosystems must start with the capture of energy by autotrophs.

D. Energy transfer from one trophic level to the other is not 100% efficient.

33. What is the critical limiting factor for plants below the photic zone in an aquatic ecosystem?

A. Availability of nutrients

B. Availability of water

C. Intensity of light

D. Carbon dioxide concentration

34. Which of the following instruments is used to estimate the number of plants in a habitat?

A. Pooter

B. Pitfall trap

C. Quadrat

D. Sweep net

35. Which of the following statements is true about sandy soil? It

A. has limited air space.

B. is light and easy to dig.

C. drains slowly.

D. is heavy and poorly aerated.

ANSWERS

36. Which of the following organisms is a primary consumer?

A! Dog

B. Sheep

C. Grass

D. Fungus

study the diagram of a food chain shown below and use it to answer questions 37 and 38. P  Q  R  S  T

37. The organism designated P in the food chain above is normally sustained by energy from

A. Sunlight.

B. Carbohydrates.

C. Green plants.

D. Mineral salts.

38. Which of the following statements best describes the organism designated R? It

A. Feeds on S.

B. Is a primary consumer.

C. Is a producer as well as a consumer.

D. Is a secondary consumer.

39. Food chains are relatively short because

A. Of energy recycling in the ecosystem.

B. Energy gain at each tropic level is high.

C. Of energy loss at each tropic level.

D. Energy flow in an ecosystem is uni-directional.

40. Which of the following organisms does not show colour adaptation to its environment?

A. Chameleon

B. Earthworm

C. Fish

D. Toad

ANSWERS

41. Most tropical plants shed their leaves during dry weather conditions in order to

A. Reduce their growth rate.

B. Conserve water.

C. Reduce competition.

D. Minimise the rate of photosynthesis.

42. Which of the following features is not an adaptation of plants to aquatic habitat?

A. Breathing roots for entry of air

B. Flowers raised above water for the purpose of pollination

C. Spongy tissues containing gases for buoyance

D. Hairy structures on the leaves to reduce water loss

43. The following habitats can be used in the study of succession except

A. Savanna grassland.

B. Abandoned farmland.

C. A pond.

D. A well cultivated land.

44. Population growth rate may be defined as the

A. Mortality rate per unit area over a period.

B. Number of times an organism occurs within a given period.

C. Number of a particular species per unit area.

D. Net rate of natality and mortality in the habitat over a period,

45. In ecological succession, since lichens grow on bare rock, they are considered to be

A. Primary consumers.

B. Pioneer organisms.

C. Climax organisms.

D. Producers.

ANSWERS

46. Which of the following factors will most likely lead to overcrowding within a population?

A. Absence of predators

B. Emigration

C. Food shortage

D. Absence of territorial behaviour

47. A species whose population has become so small that it may become extinct if not protected is a/an

A. Special species.

B. Dangerous species.

C. Endangered species.

D. Important species.

48. Which of the following practices does not contribute to the preservation and improvement of the environment?

A. Pollution reduction

B. Material recycling

C. Reafforestation

D. Overgrazing

49. Variation is important in human life and can be used for the following activities except

A. Crime detection.

B. Population distribution

C. Blood transfusion.

D. Determination of paternity.

50. An example of continuous variation is

A. Fingerprint.

B. Tongue rolling.

C. Blood grouping.

D. Body size.

ANSWERS

51. The outward appearance of an organism is referred to as

A. Phenotype.

B. Genotype.

C. Dominance.

D. Recess iveness

52. The allele responsible for sickle-cell anaemia first appeared in the tropical and subtropical regions of Asia, the Middle East and Africa. It entered the United States of America when individuals were forcibly brought over from Africa. In micro-evolutionary terms this is an example of

A. Mutation

B. Gene flow.

C. Genetic drift.

D. Natural selection.

53. Which of the following diseases is not hereditary?

A. Albinism

B. Scabies

C. Haemophilia

D. Colour blindness

54. The immediate product of meiosis in flowering plants is the

A. Sporophyte.

B. Gametophyte.

C. Zygote.

D. Pollen grain.

55. DNA in eukaryotic cells is contained in the

A. Central vacuole

B. Nucleus.

C. Iysosome

D. Golgi body

ANSWERS

56. A man who is heterozygous for the disease haemophilia marries a woman who is double recessive for haemophilia. What percentage of their offspring would have the disease?

A. 0%

B. 25%

C. 50%

D. 75%

57. A dairy farmer allowed only his best milk producing cows to mate. In succeeding generations of cows, milk production increased. This outcome is an example of

A. Artificial selection.

B. Natural selection

C. Competition.

D. Cross fertilization.

58. Cytokinesis of mitosis is a process that ensures that.

A. Each daughter cell gets the necessary organelles.

B. There is distribution of a complete set of genes into each daughter cell.

C. Daughter cells inherit new genetic combinations.

D. Worn out organelles are excluded from daughter cells

59. An animal which is active during the day is known as a

A. Nocturnal animal.

B. Diurnal animal.