BIOLOGY FORM 4

1. Study the figure below and answer questions that follow:

a) Identify the structures labelled X. (1mk)

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b) What is the importance of the structures in a legume? (2mk)
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2. Define the following terms (2mks)
a) Ornithology
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b) Morphology
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3. Explain why plants do not need an elaborate excretory system. (3mk)
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4. A form one student trying to estimate the size of onion cells observed the
following on the microscope’s field of view.

(a) Define the term resolving power. (1 mark)

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(b) If the student counted 20 cells across the field of view, calculate the
sizeof one cell in micrometers. (2marks)

5. State the economic importance of the following plant excretory products:

a) Caffeine. (1mk)
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b) Quinine. (1mk)
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c) Papain (1mk)
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6. State the role of a pooter (1mk)
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 7. Explain why it is not advisable to be in a poorly ventilated room with a burning
charcoal stove. (3marks)
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8. (a) Name the antigens that determine human blood groups (2marks)
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(b) State the adaptation that enables the red blood cells to move in blood capillaries (1mark)
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9. Identify TWO primary mechanisms used by animals to prevent entry of

microorganisms in the body (2marks)
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10. State two precautions during collection of specimen for Biology research (2marks)
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11. State the role of the following hormones in the life cycle of insects: (2marks)
Ecdysone hormone
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Juvenile hormone
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 12. Define the following terms
a) Evolution (1mk)
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b) Adaptive radiation (1mk)

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13. The diagram below represents a growth curve in a certain Phylum.

(a) Name the type of growth curve shown. (1mark)

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(b) Name the phylum where members show the type of growth curve illustrated (1mark)
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14. (a) Name TWO reproductive hormones secreted by the pituitary gland in women(2marks)
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(b)State one function of each of the hormones named in (a) above (2marks)
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15. A flower has the following characteristics:

Inconspicuous petals
Long feathery stigma

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 Small, light pollen grains
(a) What is the likely agent of pollination of the flower? (1mark)

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(b) What is the significance of the long feathery stigma on the flower? (1mark)
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16. The diagram below represents a transverse section of an ovary from a certain flower

(i) Name the structure labelled W (1mark)

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(ii) Name the type of placentation illustrated in this diagram (1mark)

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17. State the condition under which insulin hormone is released and indicate its biological
function. (3mks)
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18. List any three homeostatic functions of the kidney. (3mk)
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19. a) What is the basic unit of a DNA molecule? (1mk)

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b) Name two chemical components of the unit named in (a) above. (2mk)
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20. When a certain breed of red cows is mated with white bulls, the calves obtain a roan
colour.
a) Explain the absence of red and white colours among the calves. (1mk)
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b) If the calves were interbred, determine the phenotypes of the F2 generation. Use
letter R to represent the gene for red colour and W for white colour. (4mks)

21. The photographs below represent a type of evolution

a) State the type of evolution shown (1mk)

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b) Explain the name given to the structures represented by the photographs (2mks)
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22. Why is the pancreas considered as a dual gland (2marks)

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23. Distinguish between the terms homodont and heterodont (1mark)
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24. State two adaptations of guard cell to its functions (2marks)
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25. List two characteristics of stomata found in xerophytes (2marks)
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26. Give a reason why microscope sections require to be:

(i) Thin…………………………………………………………………………(1mk)

(ii) Kept wet …………………………………………………………………..(1mk)

27. (a)Identify the mode of feeding of the animal whose dental formula is given below(1mk)
0 0 3 2
i , c , pm , m
2 1 3 2
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(b) Give two reasons for your answer in (a) above. (2mks)
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c) What is the role of carnassial teeth (1mk)

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28. The following is diagrammatic representation of protein synthesis
x

Amino acid Amino acid

+ + H2O
R Molecule Q

a) Name processes R and molecule Q (2mks)

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b) Identify bond labeled X (1mk)
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29. Distinguish between taxonomy and taxon (2mks)
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30. The illustration shown below is of a common organism

a) Using observable features only, state its class (1mk)

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b) Give TWO reasons for your answer in (a) above (2mks)
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c) State one economic importance of the organism above (1mk)

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d) The organism above is a vector of a disease that causes destruction of red blood cells
in human. Give the scientific name of causal agent to the disease (1mk)
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31. State the roles of the following parts of a light microscope (2mks)
a) Fine adjustment knob
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b) Condenser
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