WAEC Biology 2006 past questions

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

Ten questions from the 2006 WAEC Biology paper, with answers and explanations. We hold 65 questions from this paper, and the Skolra app has all of them.

WAEC Biology 2006 questions and answers

1. 1.The part of the ear in mammals responsible for the detection of sound is the
   1. A
      semicircular canals
   2. B
      organ of Corti
      Correct
   3. C
      tympanic membrane
   4. D
      eustachian tube
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   Answer: B

   The organ of Corti is located within the cochlea of the inner ear and contains specialised hair cells that detect sound vibrations converted from mechanical movements of the ossicles. These hair cells transduce mechanical energy into nerve impulses sent to the brain via the auditory nerve. The semicircular canals detect balance and rotational movement, not sound. The eustachian tube equalises air pressure on both sides of the eardrum. The tympanic membrane (eardrum) vibrates in response to sound but is not the detection organ itself.

2. 2.

   Which of the following heart structures is best adapted To cope with double circulation?

   1. A
      The sino-atrial node
   2. B
      The bicuspid valve
   3. C
      The four-chambered structure separating oxygenated and deoxygenated blood
      Correct
   4. D
      The pulmonary artery
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   Answer: C

   Double circulation involves two separate circuits: the pulmonary circuit (heart to lungs and back) and the systemic circuit (heart to body and back). The four-chambered heart of mammals is best adapted for this because it completely separates oxygenated blood (left side) from deoxygenated blood (right side), preventing mixing and ensuring efficient oxygen delivery. The sino-atrial node controls heart rate, valves prevent backflow, but neither alone accounts for the adaptation to double circulation.

3. 3.An effective management of natural resources to ensure their continued yield from generation to generation may involve all the following except
   1. A
      Planting trees after logging operations
   2. B
      Establishing wildlife sanctuaries and protected areas
   3. C
      Mining without land reclamation
      Correct
   4. D
      Regulating the size of annual harvests
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   Answer: C

   Mining without land reclamation leaves behind degraded, infertile land stripped of topsoil and vegetation, which is the opposite of sustainable resource management. Planting trees after logging (reforestation) ensures forest renewal, regulating harvest sizes prevents overharvesting, and wildlife sanctuaries protect species from extinction. Effective management must guarantee that resources are replenished at least as fast as they are consumed, which unreclaimed mining destroys.

4. 4.

   Which of the following processes does not contribute Towards growth?

   1. A
      Transpiration
      Correct
   2. B
      Cell differentiation
   3. C
      Cell division
   4. D
      Assimilation
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   Answer: A

   Transpiration is the loss of water vapour from the aerial parts of plants, primarily through the stomata, and does not directly contribute to growth. Assimilation involves incorporating absorbed nutrients into new cells and tissues. Cell division increases cell number, and cell differentiation allows cells to specialise for different roles. All three (assimilation, cell division, and differentiation) are essential components of growth, whereas transpiration is part of the plant's water transport and cooling mechanism.

5. 5.Which of these factors does not contribute towards The ascent of water in plants?
   1. A
      Adhesion of water molecules to the walls of xylem vessels
   2. B
      Gravity acting downward on the water column in the xylem
      Correct
   3. C
      Cohesion of water molecules within the xylem vessels
   4. D
      Transpiration pull from the leaves
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   Answer: B

   Gravity acts downward on the water column and therefore opposes the ascent of water in plants rather than contributing to it. The ascent of water (transpiration stream) is driven by: transpiration pull (suction from water evaporating in leaves), cohesion (water molecules sticking together forming a continuous column), adhesion (water sticking to xylem walls), and root pressure. These forces combine to draw water from roots upward through the xylem against gravity, sometimes to heights of over 100 metres in tall trees.

6. 6.

   (a)(i) Briefly explain the term respiration.

   (ii) Name the two types of respiration and write a balanced equation to summarize each of them.

   (b) Outline the mechanisms involved in: (i) inhalation; (ii) exhalation in human beings

   1. A
      The exchange of gases between an organism and its surrounding environment
   2. B
      The breakdown of glucose to produce lactic acid without releasing energy
   3. C
      The release of chemical energy from organic molecules within living cells
      Correct
   4. D
      The absorption of oxygen and release of carbon dioxide by the lungs only
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   Answer: C

   Respiration is the process by which living cells break down organic molecules, especially glucose, to release chemical energy in the form of ATP. It occurs in two main types: aerobic respiration (C₆H₁₂O₆ + 6O₂ → 6CO₂ + 6H₂O + energy) which requires oxygen, and anaerobic respiration which occurs without oxygen. Option a describes gaseous exchange, which is a different process from cellular respiration. Respiration is an intracellular process, not limited to the lungs.

7. 7.Support in young herbaceous plants is provided by
   1. A
      lignified xylem vessels
   2. B
      turgor pressure in the cells
      Correct
   3. C
      sclerenchyma fibres
   4. D
      cork tissue in the stem
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   Answer: B

   Young herbaceous plants lack the thick, woody stems of perennial plants and rely mainly on turgor pressure for support. When plant cells absorb water by osmosis, they press outward against their cell walls, making the plant firm and upright — a state called turgidity. Lignified xylem and sclerenchyma fibres provide support in older woody plants and more mature herbaceous tissues. Cork tissue is a waterproofing and protective layer found in secondary growth, not a primary support structure in young plants.

8. 8.

   During the process of osmosis, a semi-permeable membrane allows

   1. A
      all molecules regardless of size to pass through the membrane
   2. B
      gases to pass through freely but not liquid molecules
   3. C
      solvent molecules to pass through but restricts the passage of solute molecules
      Correct
   4. D
      only solute molecules to pass through freely in both directions
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   Answer: C

   Osmosis is the movement of solvent molecules (usually water) through a semi-permeable membrane from a region of lower solute concentration to a region of higher solute concentration. The semi-permeable membrane is selectively permeable, allowing small solvent molecules to pass but blocking larger solute molecules. This selectivity is based on molecular size and membrane properties. Option a describes a freely permeable membrane, and option d incorrectly identifies solute rather than solvent molecules as the ones that cross.

9. 9.Which of the following statements about feeding relationships is correct?
   1. A
      Producers form the base of every food chain
      Correct
   2. B
      Herbivores are found only at the top of food chains
   3. C
      Decomposers always occupy the second trophic level
   4. D
      Carnivores are always found at the first trophic level
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   Answer: A

   Producers (green plants and other autotrophs) always form the base of every food chain because they capture solar energy and convert it into organic matter through photosynthesis, making energy available to all other trophic levels. Carnivores occupy the third or higher trophic levels, not the first. Decomposers break down dead organic matter and are not restricted to the second level. Herbivores (primary consumers) occupy the second trophic level, not the top of the chain.

10. 10.Study the following list of deficiency symptoms in animals; use it to answer the questions below I. Loss of appetite and weight; II. Delayed healing of wounds; III. Rickets; IV Sterility in animals V Failure of blood to clot; VI. Night blindness Which of the following combination of food substances would correct the deficiency numbered II?
    1. A
       Vitamin D
    2. B
       Vitamin B12
    3. C
       Vitamin A
    4. D
       Vitamin C (ascorbic acid)
       Correct
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    Answer: D

    Deficiency II (delayed healing of wounds) is caused by a lack of Vitamin C (ascorbic acid), which is essential for the synthesis of collagen, the structural protein needed for wound repair and connective tissue formation. Without adequate Vitamin C, collagen production is impaired and wounds heal slowly — a condition seen in scurvy. Vitamins D, A, and B12 are associated with rickets, night blindness, and anaemia respectively, not wound healing.

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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