NECO Biology past questions and answers

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

NECO Biology: 335 objective past questions from 8 papers between 2000 and 2009, each with the answer and an explanation. Newer NECO papers are not in our bank yet. Here are ten.

1. 1.A dehiscent fruit formed from several fused carpels with many seeds is classified as a/an
   1. A
      Drupe
   2. B
      Capsule
      Correct
   3. C
      Berry
   4. D
      Follicle
   Show answerHide answer

   Answer: B

   A capsule is a dehiscent fruit that develops from a gynoecium of two or more fused (syncarpous) carpels and contains many seeds. It splits open at maturity to release its seeds through various mechanisms such as pores, valves, or teeth. A follicle develops from a single carpel and splits along one side. A berry is an indehiscent fleshy fruit. A drupe is also indehiscent, with a stony inner layer (endocarp). Examples of capsule fruits include cotton (Gossypium), poppy (Papaver), and okra.
2. 2.The following are the functions of a worker termite EXCEPT
   1. A
      Building and repairing the nest
   2. B
      Reproducing to maintain the colony
      Correct
   3. C
      Feeding other members of the colony
   4. D
      Foraging for food
   Show answerHide answer

   Answer: B

   Reproduction is not a function of worker termites — this is exclusively the role of the queen (and king). Worker termites are sterile individuals that carry out all the labour in the colony, including foraging for food, constructing and maintaining the nest, and feeding other castes such as soldiers, the queen, and nymphs. The queen can lay thousands of eggs per day, supported entirely by the workers. This division of labour is characteristic of eusocial insects.
3. 3.Which of the following is NOT true of enzymes?
   1. A
      They are biological catalysts
   2. B
      They are consumed in the reactions they catalyze
      Correct
   3. C
      They are specific in their action
   4. D
      They are protein in nature
   Show answerHide answer

   Answer: B

   Enzymes are not consumed in the reactions they catalyze; they are regenerated at the end of each reaction cycle and can function repeatedly. They are indeed biological catalysts (true), composed of protein (true, though some RNA enzymes exist), and highly specific for their substrates due to the lock-and-key or induced-fit mechanism (true). Being reusable is one of the defining features of an enzyme.
4. 4.The process by which some organisms oxidize inorganic compounds to obtain energy is known as
   1. A
      oxidative phosphorylation
   2. B
      fermentation
   3. C
      chemosynthesis
      Correct
   4. D
      photosynthesis
   Show answerHide answer

   Answer: C

   Chemosynthesis is the process used by certain bacteria (e.g., nitrifying bacteria, sulfur bacteria) to oxidize inorganic compounds such as ammonia, hydrogen sulfide, or ferrous ions to release energy for synthesizing organic molecules. This is distinct from photosynthesis, which uses light energy. Oxidative phosphorylation is a step within cellular respiration, not a primary energy-capturing strategy from inorganic sources.
5. 5.An example of sex-linked trait is
   1. A
      Sickle cell anaemia
   2. B
      ABO blood group
   3. C
      Haemophilia
      Correct
   4. D
      Albinism
   Show answerHide answer

   Answer: C

   Haemophilia is a blood clotting disorder caused by a recessive allele carried on the X chromosome, making it a classic sex-linked trait. Because males have only one X chromosome (XY), a single copy of the recessive allele causes the disease in males, whereas females (XX) need two copies to be affected. Sickle cell anaemia and albinism are both autosomal recessive conditions (not linked to sex chromosomes), and ABO blood group is autosomal with codominant alleles.
6. 6.Which of the following organisms maintains a fairly constant body temperature?
   1. A
      Lizard
   2. B
      Frog
   3. C
      Crocodile
   4. D
      Dog
      Correct
   Show answerHide answer

   Answer: D

   A dog is a mammal and therefore a homoiotherm (endotherm), meaning it can internally regulate and maintain a fairly constant body temperature regardless of environmental temperature through metabolic heat production. Lizards, frogs, and crocodiles are all ectotherms (poikilotherms): their body temperature fluctuates with the surrounding environment, and they rely on external sources of heat such as sunlight to warm their bodies. This distinction between warm-blooded and cold-blooded animals is fundamental to vertebrate physiology.
7. 7.These groups of bacteria are harmless EXCEPT
   1. A
      Nitrogen-fixing bacteria
   2. B
      Symbiotic bacteria
   3. C
      Saprophytic bacteria
   4. D
      Pathogenic bacteria
      Correct
   Show answerHide answer

   Answer: D

   Pathogenic bacteria are harmful because they invade living organisms and cause diseases like cholera and tuberculosis. Saprophytic bacteria decompose dead matter harmlessly, symbiotic bacteria live to mutual benefit with hosts, and nitrogen-fixing bacteria help soil fertility. Only pathogenic bacteria are harmful rather than harmless.
8. 8.The group of organisms at the base of the pyramid of numbers are
   1. A
      Decomposers
   2. B
      Secondary consumers
   3. C
      Producers
      Correct
   4. D
      Primary consumers
   Show answerHide answer

   Answer: C

   Producers (green plants and other autotrophs) form the base of the pyramid of numbers because they are the most numerous organisms in most ecosystems. They convert solar energy into organic matter through photosynthesis, supporting all other trophic levels. At each successive level — primary consumers, secondary consumers, and tertiary consumers — the number of organisms generally decreases. Decomposers are not typically placed within the main pyramid structure but operate alongside all trophic levels.
9. 9.The biosphere can best be defined as part of the
   1. A
      atmosphere where birds fly
   2. B
      soil that supports plant growth
   3. C
      earth where living organisms exist
      Correct
   4. D
      ocean where marine life thrives
   Show answerHide answer

   Answer: C

   The biosphere encompasses all regions of the earth — including the lower atmosphere, the hydrosphere, and the upper lithosphere — where living organisms exist and interact. It is not limited to any single zone such as oceans or soil. The concept underscores that life occurs across a thin layer spanning from the ocean floor to the lower troposphere.
10. 10.Which of these influences growth movement in plants?
    1. A
       Chlorophyll
    2. B
       Cellulose
    3. C
       Turgor pressure
    4. D
       Auxin
       Correct
    Show answerHide answer

    Answer: D

    Auxin is the plant hormone that controls directional growth movements like phototropism and geotropism through unequal distribution and cell elongation. More auxin accumulates on the shaded side, causing that side to grow faster and bending the organ toward light. Turgor pressure causes reversible nastic movements, chlorophyll is a pigment, and cellulose provides cell wall structure.

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 335 NECO Biology questions in the Skolra app

Every question has the answer and an explanation. Practise by year, or sit a timed NECO paper on the CBT screen.

Download for WindowsDownload for Mac

About the app · Skolra for Windows · Skolra for Mac