JAMB Biology 2023 past questions

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

Ten questions from the 2023 JAMB Biology paper, with answers and explanations. We hold 79 questions from this paper, and the Skolra app has all of them.

JAMB Biology 2023 questions and answers

1. 1.

   The membrane around the vacuole is known as

   1. A
      Tonoplast
      Correct
   2. B
      Plasma membrane
   3. C
      Nuclear membrane
   4. D
      Cell wall
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   Answer: A

   The membrane that surrounds the vacuole is called the tonoplast. It is a selectively permeable membrane that controls the movement of water and solutes into and out of the vacuole, helping to regulate turgor pressure and store cell sap.

2. 2.

   Which component of blood is responsible for carrying oxygen to the body tissues?

   1. A
      White blood cells
   2. B
      Platelets
   3. C
      Red blood cells
      Correct
   4. D
      Plasma
   Show answerHide answer

   Answer: C

   Red blood cells (erythrocytes) are correct. They contain the red pigment haemoglobin, which binds oxygen in the lungs and releases it to the body tissues.

   White blood cells are wrong because their job is defence against infection (fighting pathogens), not gas transport.

3. 3.

   A biome characterized by hot summer, cold winter and treeless vegetation is

   1. A
      Taiga (coniferous forest)
   2. B
      Tundra
   3. C
      Tropical desert
   4. D
      Temperate grassland
      Correct
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   Answer: D

   Temperate grassland is the correct answer. This biome is found in the mid-latitudes and is known for its hot summers, cold winters, and treeless vegetation made up mainly of grasses and small herbs. Examples include the prairies of North America, the steppes of Asia, and the pampas of South America.

   So the biome that matches hot summer, cold winter and treeless (grassy) vegetation is temperate grassland.

4. 4.

   Which of the following is an example of physiological variation in organisms?

   1. A
      Height of an individual
   2. B
      Colour of the eyes
   3. C
      Colour of the skin
   4. D
      Blood group of an individual
      Correct
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   Answer: D

   Variation in organisms is grouped into morphological (structural) variation and physiological (functional) variation.

   Morphological variation deals with observable physical/structural features such as height, skin colour and eye colour — these can be measured or seen directly on the body.

5. 5.

   Which of the following functions is performed by the skin to help maintain homeostasis in the human body?

   1. A
      Detection of touch, pressure and pain through sensory receptors
   2. B
      Excretion of excess salts and urea in sweat
   3. C
      Regulation of body temperature through sweating and vasodilation
      Correct
   4. D
      Synthesis of vitamin D when exposed to sunlight
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   Answer: C

   Homeostasis means keeping the internal conditions of the body constant, and body temperature is one of the key conditions the body regulates. The skin does this through sweating (evaporation cools the body when it is hot) and vasodilation/vasoconstriction of blood vessels near the skin surface (widening to lose heat, narrowing to conserve heat). This is why regulation of body temperature through sweating and vasodilation is the correct answer — it is the skin's direct contribution to homeostasis.

6. 6.

   Germination is the process in which a seed

   1. A
      becomes dormant so it can survive unfavourable conditions
   2. B
      absorbs water and permanently swells in size
   3. C
      breaks down its stored food reserves without producing a seedling
   4. D
      develops into a new plant (seedling) under favourable conditions
      Correct
   Show answerHide answer

   Answer: D

   Germination is the process in which a seed develops into a new plant (a seedling) once favourable conditions of water, oxygen and a suitable temperature are present. The embryo inside the seed resumes active growth, the radicle emerges first to form the root, followed by the plumule, which grows into the shoot.

7. 7.

   Which of the following is an example of conserving resources in an ecosystem?

   1. A
      Deforestation for timber export
   2. B
      Afforestation to replace felled trees
      Correct
   3. C
      Overgrazing of pasture land by livestock
   4. D
      Bush burning to clear farmland
   Show answerHide answer

   Answer: B

   Afforestation is the correct example of conserving resources in an ecosystem. It involves deliberately planting trees on land that has lost its forest cover (or creating new forest where none existed), which replenishes timber, wildlife habitat, soil nutrients, and water catchment for future use.

8. 8.

   Which of the following is an example of an abiotic ecological factor?

   1. A
      Predation
   2. B
      Parasitism
   3. C
      Temperature
      Correct
   4. D
      Competition for food
   Show answerHide answer

   Answer: C

   Ecological factors are grouped into two types: abiotic (non-living, physical or chemical components of the environment) and biotic (living components, arising from interactions between organisms).

   Temperature is a physical condition of the environment — it has no life of its own, so it is an abiotic factor. Others in this group include light intensity, rainfall, humidity, soil pH, and wind.

9. 9.

   Which of the following is a difference between plant and animal cells?

   1. A
      Plant cells possess a nucleus while animal cells lack a nucleus
   2. B
      Plant cells possess mitochondria while animal cells lack mitochondria
   3. C
      Plant cells possess a cell membrane while animal cells lack a cell membrane
   4. D
      Plant cells possess a cell wall made of cellulose while animal cells lack a cell wall
      Correct
   Show answerHide answer

   Answer: D

   The correct difference is that plant cells have a cellulose cell wall, while animal cells do not. The cell wall is a rigid outer layer that surrounds the cell membrane in plant cells, giving them a fixed shape and support. Animal cells have no such wall — they are bounded only by a flexible cell membrane, which is why their shape can vary.

10. 10.

    Which of the following statements about viruses is true?

    1. A
       They can reproduce only inside a living host cell
       Correct
    2. B
       They possess a cellular structure with a distinct nucleus and cytoplasm
    3. C
       They are able to carry out respiration and metabolism independently
    4. D
       They contain both DNA and RNA as their genetic material
    Show answerHide answer

    Answer: A

    Viruses can reproduce only inside a living host cell — this is the true statement.

    A virus is not a cell. It has no cytoplasm, no nucleus, no ribosomes and no enzymes of its own for respiration or metabolism, so it cannot carry out any life process on its own outside a host. Once it invades a living cell, it takes over the host's machinery to make copies of itself. This is why viruses are described as obligate intracellular parasites.

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

Spotted a wrong answer? Tell us from the app or on the contact page and we check it.

Practise all 79 questions we hold from the 2023 paper, on a timed CBT screen

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