Biology 2021 Past Questions | WAEC
16. Which of the following hormones is suddenly secreted into the bloodstream of a frightened person?
- A. insulin
- B. adrenaline
- C. thyroxine
D. parathormore
17. The temperature control centre in mammals is located in the?
- A. skin
- B. hypothalamus
- C. pituitary gland
- D. adrenal gland
18. 
The diagram above is an illustration of a type of eye defect in humans. Study it and answer this question.
The eye defect illustrated in the diagram is?
- A. hypermetropia
- B. astigmatism
- C. presbyopia
- D. myopia
19. 
The diagram above is an illustration of a type of eye defect in humans. Study it and answer this question.
The eye defect can be corrected by the use of?
- A. convex lens
- B. concave lens
- C. bifocal lens
- D. cylindrical lens
20. How many gametes are produced in the pollen grain of a flowering plant before fertilization?
- A. one
- B. two
- C. three
- D. four
Biology 2021 WAEC Past Question
21. Which of the following organisms does not undergo incomplete metamorphosis?
- A. locust
- B. grasshopper
- C. butterfly
- D. cockroach
22. An enzyme reaction may begin to decline when?
- A. the optimum temperature is attained
- B. the ph of the medium is altered
- C. there is an increase in substrate concentration
- D. the atmospheric pressure is altered
23. 
The diagram above is an illustration of the growth of a plant in a water culture. After a few days, the solution turned green and the plant died. Use this to answer this question.
What precaution should have been taken to prevent the solution from turning green?
- A. use a non-green plant for the experiment
- B. aerate the solution daily
- C. cover the culture vessel with opaque paper
- D. keep cotton wool around the seedling to make it dry
24. 
The diagram above is an illustration of the growth of a plant in a water culture. After a few days, the solution turned green and the plant died. Use this to answer this question.
The death of the plant was likely caused by?
- A. excess supply of nutrients to the plant
- B. inadequate supply of water to the plant
- C. algal growth in the solution that used up the nutrients
- D. inability of the plant to make food due to lack of sunlight
25. Which of the following factors is not necessary for photosynthesis?
- A. water
- B. carbon (IV) oxide
- C. wind
- D. sunlight
26. Autotrophic nutritionis a process whereby an organism obtains food
- A. by utilizing its store energy
- B. by synthesizing simple substances using energy
- C. from other organisms in exchange for some products
- D. in a synthesized form, from other living organisms
27. The process that takes place at the light stage of photosynthesis is?
- A. splitting of water molecules to form hydrogen ions
- B. reduction of carbon (IV) oxide to form carbohydrate
- C. formation of two molecules of phosphoglyceric acid
- D. breaking down of ATP molecules to produce energy
28. 
The diagram above is an illustration of the foot of an animal.
The adaptation of this type of foot is that it is?
- A. used as a bait to catch fish in water
- B. used as a paddle for swimming
- C. effective in scratching the soil for food
D. used for killing prey in water
29. The following organisms are examples of carnivorous plants except.
- A. gloriosa
- B. venus flytrap
- C. pitcher plant
- D. Utricularia
30. Plants and animals of an ecosystem make up a?
- A. habitat
- B. succession
- C. community
- D. population
