WAEC Biology 2005 past questions

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

Ten questions from the 2005 WAEC Biology paper, with answers and explanations. We hold 65 questions from this paper, and the Skolra app has all of them.

WAEC Biology 2005 questions and answers

1. 1.Only specially adapted micro-organisms are found in
   1. A
      Temperate grasslands with moderate rainfall and seasonal temperature changes
   2. B
      Freshwater lakes with abundant dissolved oxygen and neutral pH
   3. C
      Tropical rainforests with consistently high humidity and temperature
   4. D
      Hot springs and highly saline (hypersaline) environments
      Correct
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   Answer: D

   Extremophile micro-organisms are those adapted to survive in environments with extreme physical or chemical conditions that would kill most other life. Hot springs may reach temperatures above 70°C, requiring thermophilic bacteria with heat-stable enzymes. Hypersaline environments such as salt lakes have water potential so low that most cells would lose water by osmosis and die; halophilic bacteria counter this with high internal solute concentrations. These are environments where only specially adapted species (extremophiles) can thrive.

2. 2.In active transport, molecules move against a concentration gradient, therefore
   1. A
      The process occurs spontaneously without any energy expenditure from the cell
   2. B
      Energy in the form of ATP must be expended to drive the process
      Correct
   3. C
      The cell membrane must be freely and equally permeable to all substances
   4. D
      Only water molecules can be moved by this transport mechanism
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   Answer: B

   Active transport moves molecules from a region of lower concentration to a region of higher concentration — that is, against the concentration gradient. This is thermodynamically unfavorable and requires the cell to provide energy. That energy comes from the hydrolysis of ATP (adenosine triphosphate). Special carrier proteins in the membrane use this ATP energy to physically move specific molecules across. This is how plant roots accumulate mineral ions from the soil at concentrations higher than those in the surrounding water.

3. 3.Reading the verdict of a case by a judge or magistrate is an example of
   1. A
      learned behaviour
      Correct
   2. B
      reflex action
   3. C
      kinesis
   4. D
      innate behaviour
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   Answer: A

   Learned behaviour is behaviour that is acquired through experience, training, and exposure rather than being present at birth. Reading a verdict requires literacy and judicial training, making it a clear example of learned behaviour. Innate behaviour is genetically programmed and present without any prior learning. Reflex actions are rapid, automatic responses to stimuli and do not involve conscious reasoning or prior learning.

4. 4.

   (a) Write short notes on the following:
   (i) habitat
   (ii) ecological niche.

   (b) (i) List three instruments used in the measurement of different ecological factors.
   (ii) Briefly state what each instrument listed in (b) (i) above is used for.

   (c) Name; (i) three plants (ii) two animals found in savannah vegetation.
   

   1. A
      The physical location where an organism lives, determined solely by soil type
   2. B
      The functional role and position of an organism within its ecosystem, including its feeding habits and interactions
      Correct
   3. C
      The seasonal migration pattern of animals between different vegetation zones
   4. D
      The total biomass of all organisms occupying a given geographical region
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   Answer: B

   An ecological niche describes the functional role an organism plays in its community, encompassing what it eats, how it obtains food, and how it interacts with other species. It is broader than a habitat, which refers simply to the physical place where the organism lives. A habitat is where the organism lives, while the niche is 'how' it lives there. For example, two species can share the same habitat but occupy different niches by feeding on different food sources.

5. 5.Which of the following organisms is a social insect?
   1. A
      grasshopper
   2. B
      mosquito
   3. C
      termite
      Correct
   4. D
      housefly
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   Answer: C

   Termites are classic social insects that live in highly organised colonies comprising a queen, king, workers, and soldiers, each with specific roles. Social insects are characterised by eusociality — cooperative brood care, overlapping generations, and reproductive division of labour. Ants, bees, wasps, and termites are the major social insects. The mosquito, grasshopper, and housefly are solitary insects that do not form organised colonies with division of labour.

6. 6.Which of the following pairs of organisms are photosynthetic?
   1. A
      Spirogyra and Euglena
      Correct
   2. B
      Rhizopus and Euglena
   3. C
      Amoeba and Paramecium
   4. D
      Mushroom and tapeworm
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   Answer: A

   Spirogyra is a filamentous green alga containing ribbon-like chloroplasts and is fully photosynthetic. Euglena also contains chloroplasts and photosynthesizes in the presence of light. Mushroom is a fungus that feeds saprophytically; tapeworm is a parasitic animal; Amoeba and Paramecium lack chloroplasts and are heterotrophic; Rhizopus is a fungus and is also not photosynthetic. Therefore, Spirogyra and Euglena are the only pair in which both organisms are photosynthetic.

7. 7.A major difference between plants and animals is that
   1. A
      Plants can manufacture their own organic food through photosynthesis while animals cannot
      Correct
   2. B
      Animals perform both respiration and excretion while plants perform only photosynthesis
   3. C
      Animals can reproduce sexually while plants are restricted to asexual reproduction only
   4. D
      Plants have a well-developed nervous system while animals rely on hormones alone
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   Answer: A

   The fundamental nutritional difference between plants and animals is that plants are autotrophs — they synthesize their own organic food from inorganic raw materials (carbon dioxide and water) using photosynthesis. Animals are heterotrophs and must obtain ready-made organic compounds by consuming other organisms. Both kingdoms respire, reproduce, excrete, and respond to stimuli; the capacity for photosynthesis is the defining metabolic distinction.

8. 8.The main similarity between unicellular and multicellular organisms is that both
   1. A
      Have the same number of chromosomes in each of their cells
   2. B
      Undergo meiosis as their primary and only method of cell division
   3. C
      Require a specialized circulatory system to distribute nutrients internally
   4. D
      Carry out fundamental life processes such as respiration, nutrition, and reproduction
      Correct
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   Answer: D

   All living organisms, whether single-celled or multicellular, must perform the same basic life processes: nutrition, respiration, excretion, growth, reproduction, sensitivity, and movement. In a unicellular organism such as Amoeba, all these functions are carried out within one cell. In multicellular organisms, these functions are shared among specialized tissues and organs. The need to perform these fundamental processes is the core similarity that unites all living things regardless of their structural complexity.

9. 9.Raw materials required by green plants to manufacture their food are
   1. A
      Carbon dioxide and water
      Correct
   2. B
      Oxygen and glucose released during the light reactions
   3. C
      Nitrogen, oxygen, and carbon dioxide from the atmosphere
   4. D
      Glucose, water, and dissolved mineral salts from the soil
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   Answer: A

   The raw materials (reactants) for photosynthesis are carbon dioxide (absorbed from the atmosphere through stomata) and water (absorbed from the soil through roots). Light energy, absorbed by chlorophyll, is used to convert these inorganic raw materials into glucose and oxygen. The equation is: CO₂ + H₂O → C₆H₁₂O₆ + O₂. While mineral salts are essential nutrients for plant growth, they are not direct raw materials consumed in the photosynthetic reaction itself.

10. 10.Territoriality is a phenomenon among
    1. A
       plants that produce allelopathic chemicals to exclude competitors
    2. B
       animals that defend a defined area for feeding, breeding, or shelter
       Correct
    3. C
       animals that migrate seasonally to new feeding grounds
    4. D
       social insects living exclusively in underground colonies
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    Answer: B

    Territoriality is the behaviour in which an animal defends a defined area — a territory — against rivals, usually for the purpose of securing resources such as food, mates, or nesting sites. It is observed in many vertebrates including birds, fish, and mammals, as well as some invertebrates. The defending individual uses threat displays, vocalisations, scent marking, or direct aggression. Territoriality reduces competition for resources and promotes reproductive success by giving the territory holder preferential access to mates.

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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