WAEC Biology 2021 past questions

Checked by the Skolra question team · Last updated 23 October 2026

Ten questions from the 2021 WAEC Biology paper, with answers and explanations. We hold 58 questions from this paper, and the Skolra app has all of them.

WAEC Biology 2021 questions and answers

1.
The process that takes place at the light stage of photosynthesis is?
1. A
  Photolysis of water into hydrogen and oxygen
  Correct
2. B
  Fixation of carbon (IV) oxide by ribulose bisphosphate
3. C
  Conversion of glucose into starch for storage
4. D
  Reduction of carbon (IV) oxide to form glucose
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Answer: A
The light stage of photosynthesis takes place in the thylakoid membranes of the chloroplast, where chlorophyll traps light energy.
This energy is used to split water molecules, a process called photolysis, releasing oxygen gas as a by-product and hydrogen ions that combine with NADP to form NADPH2. ATP is also produced in this stage. These products (ATP and NADPH2) are then supplied to the dark stage.
2.
Endangered species are organisms that are?
1. A
  newly discovered and not yet classified
2. B
  reduced in number and are in danger of becoming extinct
  Correct
3. C
  widely distributed and increasing rapidly in population
4. D
  extinct and no longer found anywhere on Earth
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Answer: B
Endangered species are organisms whose numbers have become so low, mainly due to habitat destruction, over-hunting, pollution and climate change, that they are in danger of becoming extinct if nothing is done to protect them.
3.
Which of the following behaviours is correctly matched with the corresponding diseases?
1. A
  Territorial behaviour is exhibited by mosquitoes to reduce the spread of malaria
2. B
  Display behaviour in males is used to attract mates and establish dominance, not related to disease prevention
3. C
  Migratory behaviour in birds helps escape seasonal disease outbreaks in their breeding grounds
4. D
  Nocturnal behaviour in female mosquitoes enables them to feed on blood hosts, increasing malaria transmission
  Correct
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Answer: D
Nocturnal behaviour — activity at night — in female Anopheles mosquitoes is directly related to disease transmission. Female mosquitoes require blood meals for egg production, and Anopheles species are primarily active and feed at night. This nocturnal feeding behaviour on human hosts is the main route of malaria parasite transmission.
4.
Which of the following statements about mitosis is not correct?
1. A
  It occurs in somatic (body) cells for growth and repair of tissues
2. B
  Sister chromatids separate and move to opposite poles during anaphase
3. C
  Homologous chromosomes pair up along the equator during metaphase
  Correct
4. D
  It produces two daughter cells with the same chromosome number as the parent cell
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Answer: C
Mitosis is the type of cell division that occurs in somatic (body) cells for growth, repair and asexual reproduction. It produces two daughter cells that are genetically identical to the parent cell and have the same chromosome number as the parent (no reduction in chromosome number).
5.
Which of the following practices is a wildlife conservation method?
1. A
  Establishment of game reserves and national parks
  Correct
2. B
  Indiscriminate felling of trees in forest reserves to create farmland
3. C
  Bush burning to drive out animals for easy capture
4. D
  Hunting of animals throughout the year without restriction
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Answer: A
Establishment of game reserves and national parks is a genuine wildlife conservation method. These are protected areas set aside by law where animals and their habitats are safeguarded from hunting, bush burning and deforestation, allowing populations to breed and survive undisturbed.
6.
Autotrophic nutrition is a process whereby an organism obtains food
1. A
  by ingesting complex organic food and digesting it internally
2. B
  by synthesizing its own organic food from simple inorganic substances using energy from sunlight or chemical reactions
  Correct
3. C
  by absorbing already digested food materials from a host
4. D
  by feeding on dead and decaying organic matter
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Answer: B
Autotrophic nutrition is the mode of nutrition in which an organism manufactures (synthesises) its own organic food from simple inorganic raw materials, such as carbon(IV) oxide and water, using energy trapped from sunlight (photosynthesis) or from chemical reactions (chemosynthesis). Green plants and some bacteria are autotrophs.
7.
Which of the following hormones is suddenly secreted into the bloodstream of a frightened person?
1. A
  Insulin
2. B
  Testosterone
3. C
  Adrenaline
  Correct
4. D
  Thyroxin
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Answer: C
Adrenaline is the hormone suddenly released into the bloodstream when a person is frightened.
Fear activates the sympathetic nervous system, which signals the adrenal glands (specifically the adrenal medulla) to rapidly pump adrenaline into the blood. This causes the classic "fight-or-flight" changes: increased heart rate, raised blood glucose, faster breathing, and heightened alertness — all preparing the body to react quickly to danger.
8.
In humans, pointed eyebrows (B) is a dominant trait over smooth eyebrows (b). A student and the mother have smooth eyebrows while the father has pointed eyebrows. What is the genotype of the father?
1. A
  Cannot be determined from the information given
2. B
  Homozygous dominant (BB)
3. C
  Homozygous recessive (bb)
4. D
  Heterozygous (Bb)
  Correct
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Answer: D
To solve this genetics problem, work backwards from the student's genotype. The student has smooth eyebrows (recessive phenotype), which means the genotype is bb (homozygous recessive). Since the mother also has smooth eyebrows, her genotype is bb.
9.
Which of the following resources cannot be conserved?
1. A
  Water
2. B
  Soil
3. C
  Sunlight
  Correct
4. D
  Forest
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Answer: C
Sunlight cannot be conserved. Conservation means managing a resource carefully so it does not run out or get degraded for future use.
Forest, soil and water are all resources that human activities can deplete or damage — cutting down trees without replanting, poor farming that causes erosion, and pollution or overuse of water bodies. These must be actively protected and managed, which is what conservation means.
10.
A mixture of blood with antigen A and blood containing antibody a will?
1. A
  Agglutinate, as the antibody cross-links the red cells bearing antigen A
  Correct
2. B
  Show no reaction, since antigen A and antibody a are compatible
3. C
  Clot normally through the fibrinogen–fibrin pathway
4. D
  Undergo haemolysis, releasing haemoglobin into the plasma
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Answer: A
Agglutination is what happens when blood carrying antigen A meets blood containing antibody a (anti-A). Each antibody molecule has two antigen-binding arms, so it can grab antigen A on one red blood cell and antigen A on another red blood cell at the same time, linking many cells together into visible clumps.

The questions come from past JAMB, WAEC and NECO papers. We use software to help write the answer options and explanations, and every answer is checked twice before it goes on the site. How we check

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WAEC Biology 2021 past questions

WAEC Biology 2021 questions and answers

Practise all 58 questions we hold from the 2021 paper, on a timed CBT screen

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