JAMB Biology 2024 past questions

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

Ten questions from the 2024 JAMB Biology paper, with answers and explanations. We hold 24 questions from this paper, and the Skolra app has all of them.

JAMB Biology 2024 questions and answers

1. 1.

   One main feature of trees in the savanna habitat is the possession of

   1. A
      Broad, thin leaves that maximize photosynthesis
   2. B
      Buttress roots for support in waterlogged soil
   3. C
      Shallow, widely spreading fibrous roots only
   4. D
      Thick, fire-resistant bark
      Correct
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   Answer: D

   The savanna is a tropical grassland with scattered trees, long dry seasons, and regular bush fires. Trees that survive here (e.g. acacia, baobab, shea) show clear adaptations to both drought and fire.

2. 2.

   Ecological succession can result from

   1. A
      habitat with abundant food
   2. B
      population of plants on a fertile land
   3. C
      habitat with space and light
   4. D
      newly formed habitat
      Correct
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   Answer: D

   Ecological succession is the gradual, orderly change in the species composition of a community over time, starting from pioneer organisms and ending in a stable climax community.

3. 3.

   The abiotic factor that affect the population growth of an organism is

   1. A
      Disease
   2. B
      Predation
   3. C
      Competition
   4. D
      Temperature
      Correct
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   Answer: D

   Temperature is the abiotic (non-living, physical) factor that affects the population growth of an organism. Abiotic factors are the non-living components of the environment, such as temperature, light intensity, rainfall, humidity and soil pH, and they influence how fast a population can grow by affecting rates of feeding, reproduction, growth and survival.

4. 4.

   In glycolysis, glucose is broken down through series of reactions in the presence of enzyme and absence of oxygen to produce

   1. A
      Pyruvic acid
      Correct
   2. B
      Ethanol and carbon(IV) oxide
   3. C
      Carbon(IV) oxide and water
   4. D
      Lactic acid
   Show answerHide answer

   Answer: A

   Glycolysis is the first stage of respiration. It happens in the cytoplasm, does not need oxygen, and uses enzymes to break down one molecule of glucose (a 6-carbon sugar) into two molecules of pyruvic acid (a 3-carbon compound), with a small net gain of ATP and NADH.

   Pyruvic acid is correct because glycolysis stops there; what happens to it next depends on whether oxygen is available afterward.

5. 5.

   Which of the following plant is found in the ground layer of a tropical rainforest in Nigeria?

   1. A
      Fern
      Correct
   2. B
      Iroko
   3. C
      Mahogany
   4. D
      Obeche
   Show answerHide answer

   Answer: A

   A tropical rainforest is arranged in distinct vegetation layers from the tallest trees down to the forest floor: the emergent layer, the canopy layer, the shrub/understory layer, and the ground layer.

6. 6.

   Inbreeding is highly discouraged in humans because it may

   1. A
      increase genetic variation within the family line
   2. B
      reduce the rate of mutation in offspring
   3. C
      cause non-disjunction of chromosomes during meiosis
   4. D
      increase the chance that harmful recessive alleles are expressed
      Correct
   Show answerHide answer

   Answer: D

   Inbreeding means mating between close relatives, who are likely to carry the same versions (alleles) of many genes, including harmful recessive ones that are usually hidden because a normal dominant allele masks them.

7. 7.

   A community with a population of two million three hundred and ten thousand people living in an area of two thousand three hundred and ten square kilometres has a population density of

   1. A
      500 people per square kilometre
   2. B
      100 people per square kilometre
   3. C
      1,000 people per square kilometre
      Correct
   4. D
      2,000 people per square kilometre
   Show answerHide answer

   Answer: C

   Population density is calculated by dividing the total population by the total land area:

   Population = 2,310,000
   Area = 2,310 km²

   Density = 2,310,000 ÷ 2,310 = 1,000 people per square kilometre.

8. 8.

   Which of the following structures enables the exchange of gases in insects?

   1. A
      Gills
   2. B
      Lungs
   3. C
      Tracheae
      Correct
   4. D
      Book lungs
   Show answerHide answer

   Answer: C

   Tracheae are correct. Insects breathe using a tracheal system: air enters the body through small openings called spiracles along the sides of the body and travels through a branching network of tubes called tracheae, which divide into very fine tracheoles that reach individual tissues. Gas exchange (oxygen in, carbon dioxide out) happens directly at these fine tubes, without needing blood to carry the gases as in vertebrates.

9. 9.

   The total number of ATP produced during glycolysis is

   1. A
      8 molecules of ATP
   2. B
      4 molecules of ATP
      Correct
   3. C
      6 molecules of ATP
   4. D
      2 molecules of ATP
   Show answerHide answer

   Answer: B

   In glycolysis, one glucose molecule is split into two molecules of pyruvate. This happens in two stages.

   Energy-investment stage: 2 molecules of ATP are used up to activate glucose (forming fructose-1,6-bisphosphate).

   So the correct total number of ATP produced during glycolysis is 4 molecules of ATP.

10. 10.

    Bile is a greenish alkaline liquid which is stored in the

    1. A
       liver
    2. B
       duodenum
    3. C
       pancreas
    4. D
       gall bladder
       Correct
    Show answerHide answer

    Answer: D

    Bile, a greenish alkaline liquid, is produced by the liver but it is not stored there. After production, it passes through the bile duct and is stored and concentrated in the gall bladder until it is needed for digestion.

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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Practise all 24 questions we hold from the 2024 paper, on a timed CBT screen

Every question has the answer and an explanation, in the Skolra app.

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