WAEC Biology 2009 past questions

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

Ten questions from the 2009 WAEC Biology paper, with answers and explanations. We hold 65 questions from this paper, and the Skolra app has all of them.

WAEC Biology 2009 questions and answers

1. 1.

   Which of the following organisms does not show colour adaptation to its environment?

   1. A
      Grasshopper
   2. B
      Polar bear
   3. C
      Chameleon
   4. D
      Earthworm
      Correct
   Show answerHide answer

   Answer: D

   The earthworm lives underground in the soil and has a pink-brown coloration that does not serve as camouflage or colour adaptation to a visible environment — it relies on burrowing and remaining hidden rather than on colour matching. In contrast, the chameleon actively changes colour for camouflage and communication, the grasshopper is green to blend with vegetation, and the polar bear has white fur that matches the snow and ice of its Arctic habitat.

2. 2.Population growth rate may be defined as the
   1. A
      Maximum number of individuals an environment can support indefinitely
   2. B
      Total number of organisms in a population at any given time
   3. C
      Rate at which organisms migrate into a new habitat
   4. D
      Difference between the birth rate and death rate of a population over time
      Correct
   Show answerHide answer

   Answer: D

   Population growth rate is the change in the size of a population per unit time, calculated as the difference between birth rate and death rate (also accounting for immigration and emigration). When birth rate exceeds death rate, the population grows; when death rate exceeds birth rate, it declines. The total number of individuals is population size, not growth rate. The maximum number the environment can support is the carrying capacity.

3. 3.Which of the following statements about ecosystems is false?
   1. A
      An ecosystem includes both living (biotic) and non-living (abiotic) components
   2. B
      Ecosystems are self-sustaining and require no input of solar energy to function
      Correct
   3. C
      Energy flows through an ecosystem in one direction, from producers to consumers
   4. D
      Nutrients cycle continuously through an ecosystem without being lost
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   Answer: B

   The statement that ecosystems require no input of solar energy is false. All ecosystems ultimately depend on an external energy source — primarily solar (light) energy — which is captured by producers through photosynthesis and converted into chemical energy. Without this constant energy input, ecosystems would eventually run down due to the second law of thermodynamics. Nutrients do cycle, energy does flow one-way, and both biotic and abiotic components are part of ecosystems.

4. 4.

   GROUP I

   SPECIMEN A: Water Lettuce
   SPECIMEN B: Cactus Plant
   SPECIMEN C: Amaranthus spp / Talinum spp

   GROUP III

   SPECIMEN H: Lungs of mammal
   SPECIMEN J: Toad/Frog
   SPECIMEN K: Maize leaf

   Study carefully specimens H, J and K and use them to answer questions 4(a) to 4(d).

   (a) State the habitat of specimen J.

   (b) State (i) five observable features of specimen J;

   (ii) how the features in 4(b)(i) adapt specimen J to its habitat.

   (c)(i) List two differences between specimens H and J.

   (ii) State three similarities between specimen H and the skin of specimen J.

   (iii) State how the similar features named in 4(C)(i) above adapt specimen H for its functions.

   (d)(i) Classify specimen K into its phylum and class. (ii) Give three reasons for placing specimen in its class.

   (iii) List three observable features of specimen K and state how these features adapt it to its mode of life.

   1. A
      Both aquatic and terrestrial (amphibious) environments
      Correct
   2. B
      Strictly terrestrial dry land environments
   3. C
      Arboreal canopy environments
   4. D
      Strictly deep-water aquatic environments
   Show answerHide answer

   Answer: A

   Toads and frogs are amphibians, meaning they inhabit both water and land at different life stages. They breed and lay eggs in water, while adults can move on land, breathing through moist skin and lungs. Their moist permeable skin allows cutaneous respiration but requires a damp environment to prevent desiccation. They are never found in strictly dry terrestrial or deep-water habitats.

5. 5.Which of the following organisms is an endoparasite?
   1. A
      Tick
   2. B
      Louse
   3. C
      Tapeworm
      Correct
   4. D
      Mite
   Show answerHide answer

   Answer: C

   An endoparasite lives inside the body of its host. The tapeworm (Taenia spp.) is a classic example — it lives in the intestines of vertebrate hosts (including humans), absorbing digested nutrients through its body wall. Ticks, lice, and mites are all ectoparasites that live on the external surface (skin, hair, or feathers) of their hosts, feeding by piercing the skin to suck blood or other fluids.

6. 6.The outward appearance of an organism is referred to as
   1. A
      Phenotype
      Correct
   2. B
      Karyotype
   3. C
      Genotype
   4. D
      Homozygous constitution
   Show answerHide answer

   Answer: A

   The phenotype refers to the observable physical characteristics and traits of an organism — what it looks like, including its morphology, physiology, and behaviour. The phenotype results from the interaction of the organism's genotype (genetic makeup) with environmental factors. The genotype is the actual genetic composition (alleles present), while karyotype refers to the number and arrangement of chromosomes visible under a microscope.

7. 7.The part of the ear which contains nerve cells sensitive to sound vibrations is the
   1. A
      Eustachian tube
   2. B
      Organ of Corti in the cochlea
      Correct
   3. C
      Semi-circular canals
   4. D
      Oval window
   Show answerHide answer

   Answer: B

   The organ of Corti, located within the cochlea of the inner ear, contains specialised hair cells (mechanoreceptors) that detect sound vibrations. When sound waves cause fluid in the cochlea to vibrate, the hair cells are stimulated and generate nerve impulses that travel via the auditory nerve to the brain for sound interpretation. The semi-circular canals detect rotational movement, the oval window transmits vibrations, and the Eustachian tube equalises air pressure.

8. 8.Which of the following statements is true about sandy soil? It
   1. A
      Has very small particles that bind tightly to retain large amounts of water
   2. B
      Has large particles with big air spaces that allow water to drain quickly
      Correct
   3. C
      Is rich in organic matter (humus) and supports abundant microbial activity
   4. D
      Is highly fertile and ideal for growing all types of crops without fertilisation
   Show answerHide answer

   Answer: B

   Sandy soil is composed of relatively large particles with large pore spaces between them. This structure allows water to drain rapidly (high permeability and low water retention), meaning sandy soils dry out quickly. They are also poorly fertile because they hold few nutrients, have low organic matter content, and support less microbial activity compared to loam or clay soils. Sandy soils are not good at retaining water or nutrients for plant growth.

9. 9.

   The allele responsible for sickle-cell anaemia first appeared in the tropical and subtropical regions of Asia, the Middle

   East and Africa. It entered the United States of America when individuals were forcibly brought over from Africa. In micro-

   Evolutionary terms this is an example of

   1. A
      Gene flow (migration) transferring alleles between populations
      Correct
   2. B
      Natural selection acting against sickle-cell carriers
   3. C
      Genetic drift causing random changes in allele frequency
   4. D
      A genetic mutation occurring simultaneously in two populations
   Show answerHide answer

   Answer: A

   Gene flow (also called migration) is the transfer of genetic material (alleles) from one population to another through the movement of individuals or their gametes. When enslaved Africans carrying the sickle-cell allele were brought to the Americas, they introduced this allele into the new population, increasing its frequency there. This is a classic example of gene flow changing allele frequencies in a receiving population. Genetic drift, mutation, and natural selection are different micro-evolutionary mechanisms.

10. 10.A species whose populations has become so small that it may become extinct if not protected is a/an
    1. A
       Endangered species
       Correct
    2. B
       Invasive species
    3. C
       Vulnerable species
    4. D
       Indicator species
    Show answerHide answer

    Answer: A

    An endangered species is one whose population has declined to the point where it faces a very high risk of extinction in the wild if the causal factors (habitat loss, hunting, climate change) continue unchecked. Vulnerable species face a high risk but are not yet at imminent danger of extinction. An invasive species is one introduced to a new habitat where it outcompetes native species, and an indicator species is used to monitor environmental health.

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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