WAEC Biology 2019 past questions

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

Ten questions from the 2019 WAEC Biology paper, with answers and explanations. We hold 64 questions from this paper, and the Skolra app has all of them.

WAEC Biology 2019 questions and answers

1. 1.

   A man whose blood group is heterozygous B is married to a woman whose blood up is also heterozygous B

   Which of the following statements is correct about the blood group of their four offspring?

   1. A
      All four offspring will have blood group O
   2. B
      Two will have blood group B and two will have blood group O
   3. C
      Three offspring will have blood group B and one will have blood group O
      Correct
   4. D
      All four offspring will have blood group B
   Show answerHide answer

   Answer: C

   Both parents are heterozygous B with genotype I^B i. Their cross (I^B i × I^B i) yields offspring in the ratio: I^B I^B : I^B i : I^B i : ii = 1 : 2 : 1. Phenotypically, three offspring (I^B I^B and I^B i) express blood group B while one (ii) expresses blood group O, giving a 3:1 phenotypic ratio. This follows Mendel's Law of Segregation applied to ABO blood group inheritance.
2. 2.

   In a complete dominance monohybrid cross between a pure breedingyellow-flowered plant Y and a pure breeding white-floweredplant y, the result of the first filial generation is _________

   1. A
      all yellow-flowered plants
      Correct
   2. B
      25% yellow and 75% white-flowered plants
   3. C
      50% yellow and 50% white-flowered plants
   4. D
      all white-flowered plants
   Show answerHide answer

   Answer: A

   In a cross between a pure-breeding yellow-flowered plant (YY) and a pure-breeding white-flowered plant (yy), all F1 offspring have the genotype Yy. Because yellow (Y) is completely dominant over white (y), the recessive white allele is entirely masked and all F1 plants exhibit the yellow phenotype. This result demonstrates Mendel's First Law: the dominant trait appears in all first filial generation offspring when two true-breeding contrasting forms are crossed.
3. 3.

   Organisms in an ecosystem are usually grouped according to their trophic level into__________

   1. A
      habitats, niches, and biomes
   2. B
      producers, consumers, and decomposers
      Correct
   3. C
      communities, populations, and individuals
   4. D
      autotrophs and chemotrophs only
   Show answerHide answer

   Answer: B

   Organisms in an ecosystem are classified into functional groups by their trophic level — the position they occupy in a food chain. Producers (autotrophs such as green plants) capture energy from sunlight through photosynthesis. Consumers (heterotrophs) obtain energy by eating producers or other consumers and are subdivided into primary, secondary, and tertiary consumers. Decomposers (bacteria and fungi) break down dead organic matter and return nutrients to the soil, completing the nutrient cycle.
4. 4.

   Underground storage stems which grow horizontally in the soil are_______

   1. A
      rhizomes
      Correct
   2. B
      bulbs
   3. C
      tubers
   4. D
      corms
   Show answerHide answer

   Answer: A

   Rhizomes are modified underground stems that grow horizontally through the soil. They store food (starch) and bear nodes from which roots grow downward and aerial shoots grow upward, allowing vegetative propagation. Examples include ginger (Zingiber officinale), turmeric, and couch grass. Corms are short, upright, swollen stem bases; bulbs are compressed stems with fleshy leaf bases; and stem tubers (such as potato) are swollen stem tips but are not necessarily horizontal.
5. 5.

   An example of organ level of organization is _______

   1. A
      the liver, composed of hepatocytes, blood vessels, and connective tissue
      Correct
   2. B
      the digestive system, comprising the stomach, intestines, and associated glands
   3. C
      a single epithelial cell lining the intestine
   4. D
      epithelial tissue forming the lining of the stomach wall
   Show answerHide answer

   Answer: A

   The organ level of biological organisation refers to a structure made up of two or more different types of tissues working together to perform a specific function. The liver is a classic example — it contains hepatocyte tissue (parenchyma), blood vessels (vascular tissue), bile ducts (epithelial tissue), and connective tissue, all cooperating to perform detoxification, bile production, and metabolic functions. A single cell is the cellular level; tissue is the tissue level; and the digestive system represents the organ system level.
6. 6.Which of the following statements is not true about hormones?
   1. A
      Hormones are produced in large quantities and stored in the blood for long periods
      Correct
   2. B
      Hormones are secreted directly into the bloodstream by ductless glands
   3. C
      Each hormone acts on a specific target organ or tissue
   4. D
      Hormones are chemical messengers produced by endocrine glands
   Show answerHide answer

   Answer: A

   It is NOT true that hormones are produced in large quantities and stored in the blood for long periods. Hormones are actually produced in very small (minute) quantities and are effective at extremely low concentrations. They are generally secreted on demand and rapidly broken down or excreted after acting on their target organs. This ensures that hormonal effects are tightly regulated. The other statements — secretion into the bloodstream, specificity to target organs, and production by endocrine glands — are all true.
7. 7.

   Light is excluded from a water culture experiment in order to________

   1. A
      force the plant to absorb more minerals through osmosis
   2. B
      prevent evaporation of water from the culture vessels
   3. C
      maintain a constant temperature in the nutrient solution
   4. D
      prevent the growth of algae which would compete with the experimental plant for mineral nutrients
      Correct
   Show answerHide answer

   Answer: D

   In water culture (hydroponics) experiments, light is excluded from the nutrient solution containers to prevent algal growth. Algae are photosynthetic organisms that thrive in nutrient-rich, lit conditions; if allowed to grow, they would compete with the experimental plant for the mineral ions in the solution, invalidating results. Excluding light ensures that only the test plant uses the nutrients, so the effects of specific mineral deficiencies or supplementation can be accurately observed.
8. 8.

   Specimen A - Thermometer

   Specimen B - Rain gauge

   Specimen C - Meter rule

   Specimen D - Sweep net

   Specimen E - Wind vane

   Specimen F - Quadrat

   Specimen H - Quill feather

   Specimen J - Palm frond

   Specimen P - Cockroach

   Specimen Q - Grasshopper

   Study Specimens P, and Q and answer questions 4(a) to 4(e).

   (a)(i) State the sex of specimen P.

   (ii) Give one reason tor the answer in 4(a).

   (b)(i) Name the habitats of each of specimens P and Q (ii) State three adaptations each of specimens P and Q to their habitats. (c)(i) State one observable structural differences between specimens (ii) State three observable structural similarities between P and Q. (d)(i) Observe the mouthpart of specimen Q and state its feeding mechanism.

   (ii) List one food which specimen Q feeds on.

   (e) Remove carefully one of the legs on the right side of the metathorax of specimen P. Make a drawing, 6 cm to 8 cm long of the removed leg and label fully.

   1. A
      a narrower abdomen with longer wings extending beyond the abdomen
   2. B
      a broader, more rounded abdomen with a brood pouch and no anal styles
      Correct
   3. C
      three pairs of jointed legs and three distinct body regions
   4. D
      a pair of large compound eyes and three simple eyes (ocelli)
   Show answerHide answer

   Answer: B

   A female cockroach can be identified by its broader, more rounded abdomen compared to the narrower abdomen of the male. The female also lacks the anal styles (small paired appendages) found in males, and her abdomen is distinctly wider to accommodate the egg case (ootheca). The brood pouch where the ootheca is carried is another distinguishing feature unique to the female.
9. 9.

   Which of the following forms of energy is utilized during photosynthesis?

   1. A
      Thermal energy from the environment
   2. B
      Chemical energy stored in glucose
   3. C
      Kinetic energy of water molecules
   4. D
      Light energy from the sun
      Correct
   Show answerHide answer

   Answer: D

   Light energy from the sun is the primary energy input for photosynthesis. In the light-dependent reactions occurring in the thylakoid membranes of chloroplasts, chlorophyll and other pigments absorb photons of light. This energy is used to split water molecules (photolysis), releasing oxygen, and to generate ATP and NADPH. These energy-carrying molecules then power the Calvin cycle (light-independent reactions), where carbon dioxide is fixed into glucose.
10. 10.

    Individuals with blood group AB can donate blood to individuals with blood group(s)___________?

    1. A
       A and B only
    2. B
       AB only
       Correct
    3. C
       A, B, and AB
    4. D
       O, A, B, and AB
    Show answerHide answer

    Answer: B

    Blood group AB individuals have both A and B antigens on their red blood cells. When AB blood is transfused into a recipient with blood group A, B, or O, the recipient's plasma contains antibodies (anti-B, anti-A, or both anti-A and anti-B respectively) that will attack the donated AB cells. Only individuals with blood group AB (who have neither anti-A nor anti-B antibodies) can safely receive AB blood. AB is therefore the universal recipient but the most restricted donor.

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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