46. In humans, pointed eyebrows (B) is a dominant trait over smooth eyebrows (b). A student and the mother have smooth eyebrows while the father has pointed eyebrows. What is the genotype of the father?
- A. BB
- B. Bb
- C. bb
- D. BBbb
47. A woman with Rhesus negative blood group was advised not to marry a man with Rhesus positive blood group because
- A. it will hinder her from having blood transfusion from her husband
- B. it will result in sickness and probably death of the offspring
- C. her children may all resemble her husband
- D. it may affect her childbearing ability
48. Which of the following organisms exhibits division of labour?
- A. butterfly
- B. cockroach
- C. termite
- D. housefly
49. Natural selection arises as a result of?
- A. gene mutation
- B. change of habitat
- C. reduction in population
- D. climate change
50. Which of the following statements is not Lamarck’s postulate on evolution?
- A. great changes in the environment result in corresponding changes in species
- B. frequently used organs become well developed while the ones not used become vestigial
- C. well developed acquired characters are inheritable
- D. survivors in a competitive community must have inherited useful traits
BIOLOGY 2021 THEORY PAST QUESTIONS
1. A sample of human blood was put in a test tube and allowed to spin in a centrifuge. The components of the blood sample were clearly separated.
(a) List the four main components of blood that would be in the test tube.
(b) Name the component of the blood that: (i) would form the top layer in the test tube, (ii) destroys pathogens; (iii) is biconcave in shape (iv) would be relatively low in a haemophilic condition (v) is produced in the bone marrow: (vi) is a thrombocyte; (vii) is nucleated.
(c) Mention three chemical substances transported by the blood component named in 1(b)(i).
(d) List four diseases associated with blood.
(e) Explain briefly why a disease of the blood could be dangerous.
2. (a) What is dentition in animals?
(b) Describe briefly the generalised structure of a tooth in animals.
(c) List three food substances that plants manufacture from glucose.
(d) Make a diagram, 6 cm to 8 cm long of an experimental set-up to show that oxygen is produced during photosynthesis.
3. (a) Complete the table below by placing each of the following organisms under the appropriate heading: Algae, Bacteria, Dog, Water lettuce, Tadpole, Cat, Lemna, Waterleaf, Mucor, Mushroom
(b)(i) Name four products of decomposition (ii) Mention three roles of decomposers on a refuse dump
(c) List three materials found in a refuse dump which would not be affected by the action of decomposers.
4. (a) Complete the table below by naming five wildlife animals in West Africa and one body part each that makes them endangered because of the activities of humans
(b) State three effects each of the following factors on conservation of natural resources: (i) poor economy of a nation (ii) poaching
(c) State four roles played by the Government in conservation of natural resources
5. (a) Complete the table below by naming the nutrient cycle that involves each of the given processes and give three other processes involved in the nutrient cycle.
(b)(i) What is irritability?
(ii) Complete the table below by stating the type of response elicited by each of the given actions.
(c) Name three animals each that exhibit: (i) territoriality (ii) seasonal migration (iii) display