Term 3 Form 3 Biology Exam Paper 1

What is meant by:

i)Autecology(1mk)

ii) Synecology?(1mk)

 

2. Name the process of fruit formation without fertilization. (1mk)

 

3. State two ways in which some fungi are harmful to man. ( 2mks)

 

4. Give the role of each of the following hormones in menstrual cycle. (3mks)
5. a) Progesterone

 

1. b) Oestrogen

 

1. c) Luteinising Hormone

 

5. What is the importance of osmo-regulation in organisms?(2mks)

6.The diagram below shows a section through the mammalian skin.

a)Name the parts labeled E, F and G.  (3mks)

E

F

G

1. b) State ONE function of the substance secreted by the structure labeled I. (1mk)
2. Give a reason why it is necessary for frogs to lay many eggs. (1mk)

 

 

8. To estimate the population size of crabs in a certain lagoon, traps were laid at random. 400 crabs were caught, marked and released back into the lagoon. Four days later, traps were laid again and 374 crabs were caught. Out of the 374 caught, 80 crabs were found to be marked.

 

(a) calculate the population size of the crabs in the lagoon using the  formula below

P =

Where P = Total population of crabs  in the  lagoon

n = Total number of crabs  in the second catch

M = Number of marked crabs  during the  first

m= Number of marked crabs in the  second catch

(2mks)

 

(b) State one assumption that was made during the investigation(1mk)

 

 

(c) What is the name given to this method of estimating thepopulation size? (1mk)

 

9.State three characteristics that ensure cross -pollination takes place in

floweringplants.(3mks)

 

 

10. A student caught an animal which had the following characteristics:

Body divide into two parts

Simple eyes

Eight legs

Name the class to which the animal belongs.(1mk)

 

11.State two ways in which xylem vessels are adapted to their function(2mks)

 

12. A person was found to pass out large volumes of dilute urine frequently.

Name the

1. a) Disease the person was suffering from(1mk)

 

1. b) Hormone that was deficient(1mk)

 

13. Which organelle would be abundant in:

a)Skeletal muscle cell?(1mk)

 

b)Palisade cell?(1mk)

14. The diagram below represents a section of a leaf

(a) Name the part labeled X  (1mk)

 

(b) Give the role of the structure labelled Y(1mk)

 

(c) State two ways in which a leaf is suited to gaseous exchange (2mks)

 

15. What is the relationship between leguminous plants and bacteria found in their

root nodules? (1mk)

 

16. In an experiment to investigate a factor affecting photosynthesis, a leaf of a

potted plant which had  been  kept  in the dark overnight was covered with

Aluminium foil as shown in the diagram below

The set up was kept in sunlight for three hours after which a food test was

carried out on the leaf.

 

• Which factor was being investigated in the experiment?(1mk)

 

• What food test was carried out?(1mk)

 

• State the results of the food test(1mk)

 

 

(d) Why was it necessary to keep the plant in darkness before the experiment started?(1mk)

 

17.Explain why sexual reproduction is important in organisms  (2mks)

 

18. Name two factors in seeds that cause dormancy. (2mks)

 

19. Give areason for each of the following:

a)Constant body temperature is maintained in mammals.(1mk)

 

b)Low blood sugar level is harmful to the body.(1mk)

 

20. The diagram below represents human foetus in a uterus.

1. a) Name the part labeled S.                                     (1mk)

 

b)Name the types of blood vessels found in the structure labeled Q. (2mks)

 

1. c) State the role of the part labeled R (1mk)

 

21.What is the role of water in a germinating seed    (2mks)

 

22.Why are green plants referred to as primary producers in an ecosystem. (2mks)

 

23. Name two processes that bring about the translocation of manufactured food (2mks)

 

24. The diagram below represents a set up that was used to investigate a certain process in green plants.

a)What process was being investigated?                                                        (1mk)

 

 

b)(i)State one  precaution that should be taken when setting

up the experiment.                                                                                   (1mk)

 

1. c) State two environmental factors that would influence the process

under investigation.                                                                                                (2mks)

 

 

25. Ascaris/lumbricoides is an example of an endoparasite.
26. a) What does the name Ascaris refers to? (1mk)

 

1. b) State the habitat of the organism. (1mk)

 

1. c) State two ways in which the organism is adapted to living in its habitat. (2mks)

 

26. a)Define the following terms

(i)Epigynous flower                                                                            (1mk)

 

(ii)Staminate flower?                                                                          (1mk)

 

 

b)How are the male parts of wind pollinated flowers adapted

to their function?                                                                                   (2mks)

 

27. The diagram below represents part of phloem tissue.

1. a) Name the structure labeled R and the cell labeled T.(2mks)

i)R_

 

ii)Cell labeled T

 

1. b) State the function of the structure labeled S (1mk)

 

28. Name two defects of circulatory system (2mks)

 

29. Explain how aerenchyma tissue is adapted to its function. (3mks)

 

 

30. What is the effect of gibberellins on shoots of plants?            (2mks)

 

 

31. A process that occurs in plants is represented by the equation below.

 

C₆H₁₂O₆                   2C₂H₅OH  +  2CO₂+ Energy

 

(Glucose)                    (Ethanol)       (Carbon dioxide)

 

1. a) Name the process (1mk)
2. b) State the economic importance of the process named in (a) above(2mks)

 

32. What is the significance of meiosis? (2mks)

Term 3 Form 3 Biology Exam Paper 2

Term 3 Form 3 Biology Exam Paper 3