SECTION A
Answer all questions in this section. For each question select the most correct option and write the letter representing it in the box provided.
1. Which one of these processes helps to lower mammalian body temperature to normal?
A. Vasodilatation
B. Vasoconstriction
C. Shivering
D. Raising of hair on the skin
2. Six fingers in man is controlled by a sex-linked recessive gene. If a normal woman marries a six fingered man, which of the children will have six fingers?
A. All the sons
B. All the daughters
C. All will be normal
D. Half the number of girls and boys will be normal
3. Which one of the following tissues has a protective function in plants?
A. Xylem
B. Phloem
C. Cambium
D. Epidermis
4. What disease would you be controlling by pouring molluscicides in water?
A. Schistosomiasis.
B. Guinea worm infestation
C. Typhoid
D. Cholera
5. Which one of the following takes place by the process of active transport in plants?
A. Uptake of water
B. Intake of carbon dioxide
C. Transpiration
D. Uptake of mineral salts
6. In an ecosystem, the survival of all living things depends on
A. Decomposers
B. Primary producers
C. Primary consumers
D. Secondary consumers
7. If a gecko on a wall is seen eating mosquitoes, flies, moths and grasshoppers, this animal is said to be a
A. Parasite
B. Symbiotic
C. Predator
D. Saprophyte
8. Which one of the following structural adaptation of leaves is important for light absorption during photosynthesis?
A. Dense network of veins
B. Large numbers of stomata on leaf surfaces
C. Large intercellular air spaces in the spongy layer
D. Broad and flat shapes of leaves
9. Which of the following is a function of progesterone?
A. Prepare the uterine walls for importation
B. Initiates the process of birth
C. Initiates ovulation
D. Initiates formation of corpus luteum.
10. The part of the brain that controls breathing is the
A. Cerebellum
B. Medulla oblongata
C. Cerebrum
D. Hypothalamus
11. Which of the following are respiratory surfaces in toads and frogs?
A. The mouth, webbed toes and skin
B. Nostrils, mouth and skin
C. Webbed toes, lungs and mouth
D. The mouth, lungs and skin
12.
Figure 1 shows an experiment on photosynthesis set up by a student. The soda line was used to absorb
A. Any oxygen given off by the plant
B. Any carbon dioxide from the air
C. Moisture from the air
D. Carbon dioxide given off by the plant.
13. Which one of the following glands produces a hormone whose normal effect is to influence the rate of heartbeat?
A. Pituitary gland
B. Islets of langerhans
C. Adrenal gland
D. Thyroid gland
14. The condition known as oxygen debt occurs during active physical exercise in animals because of the
A. Accumulation of carbon dioxide during physical exercise
B. The high rate of breathing during physical exercise
C. Accumulation of lactic acid in the body
D. Accumulation of alcohol in the body.
15. The root which grows from near the base of the trunk of some woody plants is called
A. Lateral root
B. Prop root
C. Aerial root
D. Adventitious root
16. Which one of the following farming methods would cause pollution in an aquatic habitat?
A. Mulching
B. Crop rotation
C. Use of fertilisers
D. Application of farm yard manure
17. The graph below shows changes in dry weight of a seedling of a non woody plant
What is the possible explanation for the shape of the curve in phase III? Rate of
A. Respiration is constant
B. Respiration is great than that of photosynthesis
C. Growth is highest
D. Assimilation is equal to respiration
18. Which one of the blood groups will not agglutinate with any blood serum when mixed?
A. O
B. A
C. AB
D. B
19. A male cockroach is different from the female cockroach by having
A. Styles
B. Circus
C. Longer antennae
D. Larger abdomen
20. Which of the following conditions are necessary for producing movement in vertebrates?
(i) Muscles must be attached to the end of bones
(ii) Muscular bundles must occur in pairs
(iii) One of a pair of muscles must be more strongly developed than the other
(iv) One of a pair of muscles must consist of a smooth muscle.
A. (i), (iii), (iv)
B. (i) , (ii), (iii)
C. (i), (ii), (iv)
D. (iii), (iv).
21. Which one of the following compounds is a consistuent of enzymes?
A. Lipids
B. Polysaccharides
C. Proteins
D. Vitamins
22. One of two identical twins brought up differently was fatter and healthier than the other. What kinds of variation do these show?
A. Discontinuous variation
B. Genetic variation
C. Social variation
D. Habitat variation
23. Which one of the following structures in the mammalian ear is concerned with balance?
A. Cochlea
B. Semi circular canals
C. Eustachian tube
D. Oval window
24. The type of soil with minute air spaces and high water retention capacity is
A. Sand
B. Clay
C. Sit
D. Loam
25. Which one of the following cannot be used in the classification of plants?
A. Structure of the flowers.
B. Leaf structure
C. Type of seeds
D. Leaf colour
26. Figure 3 below show some fruits. Which of them are likely to be dispersed by animals?
A. I and II
B. II and III
C. III and IV
D. I and IV
27. Which one of the following is not a property of a fully turgid plant cell?
A. The vacuole has maximum volume
B. There is no more absorption of water by the cell
C. The cell wall resists further expansion of the vacuole
D. The cytoplasm is only slightly separated from the cell wall.
28. Which one of the following diets would be recommended for an overweight person?
A. Low carbohydrate, high protein, low fat.
B. High carbohydrate, low protein, law fat.
C. High carbohydrate, high protein, low fat.
D. Low carbohydrate, low protein, high fat
29. Intestinal parasites are not digested by the host's enzymes because of
A. Possession of attachment devices
B. Secretion of large quantities of mucus
C. Having a high rate of reproduction
D. Lack of their own digestive system
30. Which one of these is the correct order in which the following organisms occur in a food chain?
A. Vulture, antelope, lion
B. Lion, vulture, antelope
C. Antelope, lion, vulture
D. Lion, antelope, vulture
SECTION B
Answer all questions in this section. Answers must be written in spaces provided.
31. The table below shows the concentrations of different substances in the glomerular filtrate and urine. Study the table and answer the questions that follow:
| SUBSTANCE | CONCENTRATIONS (%) GLOMERULA FILTRATE URINE | |
|
Water Proteins Glucose Sodium Urea |
93 0 0.1 0.3 0.003 |
95 0 0 0.35 2.0 |
a) Give any one reason for the difference in the concentration of water in the glomerular filtrate and in urine.
b) Explain the absence of proteins from both the glomerular filtrate and urine
c) (i) which substance is reabsorbed with
- The highest efficiency.................................................................
- The lowest efficiency? ................................................................
(ii) Which substance is not reabsorbed at all?
d) By what factor is urea more concentrated in urine than in the glomerular filtrate?
e) Under what condition does glucose appear in urine?
32. Figure 4 below shows a longitudinal section through the female reproductive system of a mammal.
a) Name the parts labelled A, B, C, D and E on the diagram.
b) State any two functions of B.
(i) ..............................................................................................
(ii) ................................................................................................
c) In what two ways are parts A and C adapted to their functions?
A (i)..................................................................................................
(ii).....................................................................................................
C (i)..................................................................................................
(ii)....................................................................................................
d) State any two advantages the mammalian embryo has over that of a frog during their development.
(i) ..............................................................................................
(ii) ..............................................................................................
33. a) what do you understand by the following terms:
(i) a habitat ......................................................................................
(ii) an ecosystem? .............................................................................
b) Use the following organisms to construct a food web showing their feeding relationship: chameleon, moth, grasshopper, herbaceous bug, praying mantis, predatory bug and plants.
c) What is the role of each of the following organisms in the food web:
(i) the plants ..........................................................................................
(ii)the grasshopper ................................................................................
(iii) The predatory bug?.........................................................................
d) Which one of the organisms listed above will have the least energy for any single food chain considered? Why?
34. The graphs below show the effects of temperature and pH on the activity of an enzyme in the human digestive system.
a) At what temperature and pH does the enzyme show optimal activity?
b) Suggest one reason for the sharp fall in the rate of reaction of the enzyme as shown in graph A.
c) (i) suggest the identity and location of this enzyme
(ii) Give a reason for your answer to c(i) above.
d) For the enzyme in c(i) above, suggest the food it acts on and the end products.
Food acted on....................................................................................
End products......................................................................................
SECTION C
Answer and two questions from this section.
35. a) What is growth?
b) Name the main parts responsible for producing growth in a shoot.
c) Describe an experiment you would perform to determine the region of most rapid elongation in the root of a bean seedling.
36. a) What do you understand by the term 'irritability' as applied to plants and animals?
b) Explain how plants respond to light as a factor of irritability.
c) Name any three other tropic responses in plants.
37. a) Explain how the action of muscles causes air to pass from the atmosphere into the lungs.
b) How does oxygen move from the air in the lungs into the cells of the blood?
c) Give three characteristics of an efficient respiratory organ.
38. a) What is pollution?
b) Give an outline of the human activities, in Uganda, which may in environmental pollution.