CAMEROON GCE O/L JUNE 2015 Biology PAPER 2

SECTION A

1. (a) What features do insects have in common? (8 marks)
(b) How are birds adapted for flight? (12 marks)
(c) State the economic importance of birds. (5 marks)
(Total = 25 marks)
2. (a) What is photosynthesis? (4 marks)
(b) State the differences between photosynthesis and respiration. (14 marks)
(c) How is photosynthesis important in living organisms? (7 marks)
(Total = 25 marks)

3. (a) Define the following terms:
(i) Active transport.
(ii) Osmosis.
(b) Describe an experiment to demonstrate osmosis in living tissue.
(c) How does a molecule of water from the soil get to the leaf of a plant? (2, 3 marks) (10 marks) (10 marks) (Total = 25 marks)

4. (a) Define the terms:
(i) Eutrophication.
(ii) Pollution.
(iii) Ecosystem. ( 4, 4, 5marks)
(b) How would changes in temperature affect plants? (12marks)
(Total = 25 marks)

SECTION B

5. (a) Make a large labelled diagram of the mammalian skin. (10 marks)
(b) State the functions of the parts you have labelled. (10 marks)
(c) Briefly compare the mammalian skin and the epidermis of plants. (5 marks)
(Total = 25 marks)
6. (a) Define the following terms:
(i) Homozygous.
(ii) Haploid. (2, 3 marks)
(b) When Mendel crossed pure breeding red-flowered pea plant with pure breeding white- flowered pea plant, all the members of the Fi generation had pink flowers.
Using appropriate symbols and diagrams show the possible genotypes and phenotypes if
(i) The Fi individuals are allowed to self pollinate.
(ii) An Fi individual is crossed a white- flowered parent. (20 marks)
(Total = 25 marks)
2x/5 1 0/2/B

3
7. (a) Draw a labelled diagram of the longitudinal section of a mammalian heart. (10 marks)
(b) Describe how the mammalian heart functions. (15 marks)
(Total = 25 marks)
8. (a) Define the terms:
(i) Predation,
(ii) Saprophytism. (3, 2 marks)
(b) How will you carry out a simple test to show the presence in germinating seeds of
(i) A reducing sugar.
(ii) Protein. (5, 5 marks)

(c) The table below shows the population size of both predators and preys within a certain community. The time was recorded in weeks.

Time ( weeks)                 4     7      15     20   26   36
Number of predators. 220 190 330 220 130 490
Number of preys.         340 440 200 360 640 370

(i) Plot the two curves with time on the horizontal axis and population on the vertical axis. (5 marks)
(ii) Determine the population of preys and predators at week10 and week 20.
(4 marks)
(iii) Determine the first time when the population of preys will be equal to that of predators. (1 mark) (Total = 25 marks)