JAMB Biology 2022 past questions

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

Ten questions from the 2022 JAMB Biology paper, with answers and explanations. We hold 40 questions from this paper, and the Skolra app has all of them.

JAMB Biology 2022 questions and answers

1. 1.

   The movement of Euglena towards the source of light is a?

   1. A
      Positive phototaxis
      Correct
   2. B
      Positive chemotaxis
   3. C
      Positive geotaxis
   4. D
      Positive phototropism
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   Answer: A

   Positive phototaxis is correct. Euglena is a motile, single-celled organism that swims freely using a flagellum, and it possesses a light-sensitive structure called the eyespot (stigma). When a free-moving organism moves its whole body towards a stimulus, the response is called a positive taxis; when the stimulus is light, it is specifically called phototaxis. Since Euglena swims towards the light source (to position itself for photosynthesis), this is positive phototaxis.

2. 2.

   The sum total of all observable features of an organism is?

   1. A
      Phenotype
      Correct
   2. B
      Variation
   3. C
      Genotype
   4. D
      Adaptation
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   Answer: A

   Phenotype is the sum total of all observable, physical and physiological features (characteristics) of an organism, which result from the interaction between its genes and the environment. Things like height, skin colour, blood group and leaf shape are all part of an organism's phenotype.

3. 3.

   Tall trees with buttress roots and evergreen leaves are characteristics features of?

   1. A
      Tropical rainforest
      Correct
   2. B
      Deciduous forest
   3. C
      Mangrove swamp forest
   4. D
      Guinea savanna
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   Answer: A

   Tropical rainforest is the correct answer. Its trees grow very tall, competing for sunlight beneath a closed canopy, and many develop buttress roots — wide, flange-like roots that spread from the base of the trunk to give extra support in shallow, wet soils. Because rainfall is heavy and well distributed all year, the trees keep their leaves throughout the year, making them evergreen.

4. 4.

   The correct pathway for blood flow from the heart to the tissues of mammals is?

   1. A
      Heart → aorta → arteries → arterioles → capillaries
      Correct
   2. B
      Heart → vena cava → arteries → arterioles → capillaries
   3. C
      Heart → pulmonary artery → arteries → arterioles → capillaries
   4. D
      Heart → aorta → veins → venules → capillaries
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   Answer: A

   Blood leaves the heart from the left ventricle through the aorta, the largest artery in the body. The aorta branches into smaller arteries, which further divide into narrower arterioles, and finally into the tiny, thin-walled capillaries where exchange of oxygen, nutrients and waste with the tissues actually takes place. So the correct route is: heart → aorta → arteries → arterioles → capillaries.

5. 5.

   An example of arboreal animal is?

   1. A
      Elephant
   2. B
      Earthworm
   3. C
      Whale
   4. D
      Monkey
      Correct
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   Answer: D

   Arboreal animals are animals that live mainly in trees, spending most of their life climbing and moving among branches. The monkey is a classic example of an arboreal animal — its limbs, grasping hands and tail are adapted for climbing and swinging from tree to tree.

6. 6.

   A universal recipient of blood belongs to blood group?

   1. A
      Group AB
      Correct
   2. B
      Group O
   3. C
      Group B
   4. D
      Group A
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   Answer: A

   Group AB is the universal recipient.

   The ABO blood grouping depends on the antigens on the red blood cells and the antibodies in the plasma. A person with blood group AB has both A and B antigens on their red cells, but their plasma contains neither anti-A nor anti-B antibodies. This means a group AB person can receive blood from group A, group B, group O, or group AB without their plasma attacking the donor's red cells, which is why AB is called the universal recipient.

7. 7.

   Pentadactyl plan of the fore limbs of frog, bird, horse, whale and man is a proof of?

   1. A
      Adaptive radiation
   2. B
      Divergent evolution
      Correct
   3. C
      Natural selection
   4. D
      Convergent evolution
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   Answer: B

   The pentadactyl (five-fingered) limb is a homologous structure found across many vertebrates, including frog, bird, horse, whale and man. Although the limb is used differently in each animal (jumping, flying, running, swimming, grasping), the underlying bone arrangement is the same in every case, tracing back to a common ancestor.

8. 8.

   An adaptation for defense in animals is?

   1. A
      Long proboscis for sucking nectar
   2. B
      Sharp claws for catching prey
   3. C
      Webbed feet for swimming
   4. D
      Mimicry
      Correct
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   Answer: D

   Mimicry is correct. In mimicry, an animal evolves to resemble another organism (often a dangerous or distasteful one) or its surroundings. This confuses or deters predators, so it is a true adaptation for defense.

   The other options describe adaptations for different life processes, not defense:

   Webbed feet for swimming is an adaptation for locomotion in water, helping animals like ducks and frogs move efficiently — it has nothing to do with escaping predators.

9. 9.

   Which of the following is associated with the dark stage of photosynthesis?

   1. A
      Photolysis of water
   2. B
      Fixation of carbon(IV) oxide
      Correct
   3. C
      Photophosphorylation
   4. D
      Release of oxygen
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   Answer: B

   Fixation of carbon(IV) oxide is the process that takes place during the dark stage of photosynthesis.

   Photosynthesis occurs in two stages: the light stage, which happens on the thylakoid membrane and needs light directly, and the dark stage, which happens in the stroma of the chloroplast and does not need light directly.

10. 10.

    When a colour blind woman marries a normal man, what is the probability of their son being colour blind?

    1. A
       75%
    2. B
       50%
    3. C
       25%
    4. D
       100%
       Correct
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    Answer: D

    Colour blindness is caused by a recessive gene on the X chromosome. A colour blind woman must be homozygous recessive, X^cX^c, because it takes two copies of the recessive allele for a female to show the trait. A normal man has the genotype X^CY.

    That is why the answer is 100%, not 50%. The 50% answer is a common mix-up with the pattern seen when a carrier (heterozygous, X^CX^c) mother is crossed with a normal father, where only half the sons are affected. 25% and 75% do not correspond to any valid ratio from this particular cross at all.

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 40 questions we hold from the 2022 paper, on a timed CBT screen

Every question has the answer and an explanation, in the Skolra app.

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