WAEC Biology 2001 past questions

Checked by the Skolra question team · Last updated 15 October 2026

Ten questions from the 2001 WAEC Biology paper, with answers and explanations. We hold 56 questions from this paper, and the Skolra app has all of them.

WAEC Biology 2001 questions and answers

1. 1.Carbon dioxide enters the leaf through the structure labelled
   1. A
      Xylem vessel
   2. B
      Palisade mesophyll cell
   3. C
      Phloem sieve tube
   4. D
      Stoma (stomatal pore)
      Correct
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   Answer: D

   Carbon dioxide enters the leaf through the stomata (singular: stoma), which are microscopic pores mainly found on the underside of leaves. The opening and closing of stomata is controlled by guard cells. CO₂ diffuses through these pores into the sub-stomatal air spaces and then into the mesophyll cells for photosynthesis.

2. 2.Display is a phenomenon which occurs when an animal is
   1. A
      attracting a mate
      Correct
   2. B
      searching for food
   3. C
      escaping from a predator
   4. D
      migrating to a new habitat
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   Answer: A

   Display is a behavioral phenomenon in which an animal performs specific movements, postures, color changes, or vocalizations primarily to attract a mate during courtship. Examples include a peacock spreading its tail feathers and male birds singing elaborate songs. Display can also be used in territorial defense, but its most characteristic context is courtship.

3. 3.

   The substances recycled in the soil by the activities of micro-organisms during the decay of dead organisms

   Are first utilized by the

   1. A
      Consumers (herbivores and carnivores)
   2. B
      Scavengers
   3. C
      Producers (green plants)
      Correct
   4. D
      Decomposers themselves
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   Answer: C

   After micro-organisms decompose dead organisms, the inorganic minerals and nutrients released into the soil are first utilized by producers (green plants and other autotrophs). Plants absorb these mineral ions — such as nitrates, phosphates, and sulphates — through their roots and incorporate them into organic molecules during growth. Consumers in the food chain then obtain these nutrients by feeding on the producers.

4. 4.Loam is the best type of soil for crop production because
   1. A
      it has the highest proportion of clay particles of all soil types
   2. B
      it retains water completely without allowing any drainage
   3. C
      it has the largest mineral particle size of all soils
   4. D
      it has a well-balanced mixture of sand, silt, and clay particles
      Correct
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   Answer: D

   Loam soil is best for crop production because it has a balanced mixture of sand, silt, and clay. This combination provides good drainage and aeration (from sand content), adequate water and nutrient retention (from clay and silt), and a crumbly texture that allows easy root penetration. Pure clay waterlog easily, while pure sand drains too rapidly to sustain crops.

5. 5.Which of the following groups contains a non-supporting structure in animals?
   1. A
      Bone, cartilage and shell
   2. B
      Shell, bone and cartilage
   3. C
      Muscle, bone and cartilage
      Correct
   4. D
      Cartilage, bone and exoskeleton
   Show answerHide answer

   Answer: C

   Muscle is a non-supporting structure in animals — its primary role is to produce movement through contraction, not to provide structural support. Bone, cartilage, shell, and exoskeleton are all supporting structures. The group in option c contains muscle alongside supporting structures (bone and cartilage), making it the group that includes a non-supporting structure.

6. 6.Which of the following statements is true about blood groupings?
   1. A
      A person of blood group AB has both anti-A and anti-B antibodies
   2. B
      A person of blood group AB is the universal donor
   3. C
      Blood group A individuals can receive blood from group B
   4. D
      A person of blood group O is the universal donor
      Correct
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   Answer: D

   A person with blood group O is the universal donor because their red blood cells carry neither A nor B antigens, so they will not trigger an immune reaction in recipients of any ABO blood group. Blood group AB individuals are universal recipients (not donors). Group A and B cannot freely cross-donate due to antigen–antibody incompatibility.

7. 7.Which part of the gill of fish is involved in gaseous exchange?
   1. A
      Gill rakers
   2. B
      Operculum
   3. C
      Gill lamellae
      Correct
   4. D
      Gill arch
   Show answerHide answer

   Answer: C

   The gill lamellae (the thin plate-like folds on gill filaments, also called secondary lamellae) are the functional units where gaseous exchange takes place in fish. They have a large surface area, thin walls, and a dense capillary blood supply that facilitates efficient diffusion of oxygen into the blood and carbon dioxide out. The gill arch provides structural support; gill rakers filter particles; and the operculum is a protective cover.

8. 8.

   A piece of yam weighing 1.0 gm was put into some salt solution. After 3 hours, it was removed and weighed.

   The recorded weight was 1.2gms. This simple experiment demonstrates that the

   1. A
      yam cell sap is hypertonic to the salt solution
      Correct
   2. B
      yam cell sap has the same osmotic concentration as the salt solution
   3. C
      salt solution is impermeable to water molecules
   4. D
      yam cell sap is hypotonic to the salt solution
   Show answerHide answer

   Answer: A

   The yam piece gained weight (from 1.0 g to 1.2 g), which means water moved into the yam cells from the salt solution by osmosis. This occurs when the yam cell sap is hypertonic (more concentrated in dissolved solutes) than the surrounding salt solution. Water moves by osmosis from the region of lower solute concentration (the solution) to the region of higher concentration (the cell sap).

9. 9.Which of the following is a tissue?
   1. A
      Liver
   2. B
      Kidney
   3. C
      Blood
      Correct
   4. D
      Stomach
   Show answerHide answer

   Answer: C

   Blood is a connective tissue composed of red blood cells, white blood cells, platelets, and plasma — all working together to transport substances around the body. A tissue is a group of similar cells performing the same function. The kidney, liver, and stomach are organs, each made up of several different tissues.

10. 10.Which of the following associations can upset the balance of nature?
    1. A
       Commensalism
    2. B
       Parasitism
       Correct
    3. C
       Predation
    4. D
       Mutualism
    Show answerHide answer

    Answer: B

    Parasitism can upset the balance of nature because a virulent parasite can devastate host populations, causing local extinction and disrupting food chains that depend on the host species. When a new parasite enters an ecosystem, it may encounter hosts with no evolved immunity, leading to mass mortality. Predation, mutualism, and commensalism generally operate within natural equilibria that maintain ecosystem balance.

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 56 questions we hold from the 2001 paper, on a timed CBT screen

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