NAME …………………………………………..ADM NO………….STREAM………………...
NAME OF SCHOOL ……………………………DATE……………..SIGN…………………….
ZERAKI ACHIEVERS 12.0 (2024)
FORM FOUR EXAMIATIONS
BIOLOGY THEORY
231/1
TIME: 2HRS
INSTRUCTIONS
1. All Questions are Compulsory
2. Write your Answers in the Spaces Provided
3. Wrong Spelling of Technical Terms shall be Penalized
Max Score Student’s Score
80
1. a) Define the term Diffusion (1mk
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b) Give TWO conditions required for osmosis to take place between two solutions (2mks
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2. The following diagram represents a process that takes place in some cells
a) i) Which type of reproduction is represented by the diagram above (1mk
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ii) Give a reason for your answer in ai) above (1mk
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b) Explain the importance of the process represented above to evolution (2mks
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3. Name the following organisms important in occurrence of Bilharzia disease: (2mks
a) Pathogen ……………………………………………………………………………….
b) Vector ………………………………………………………………………………….
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4. The following photomicrograph represents interaction between two organisms
Fungi
Plant
a) i) Name the feeding relationship shown above (1mk
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ii) Give a reason for your answer in ai) above (1mk
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b) Give a reason why the plant represented in the photomicrograph is a dicot (1mk
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5. a) Name the hormones involved in the following human disorders (2mks
i) Diabetes insipidus ……………………………………………………………………….
ii) Low Sodium ions concentration in the blood …………………………………………..
b) State ways in which the following organs reduce severity of Diabetes mellitus (2mks
i) Kidney …………………………………………………………………………………..
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ii) Liver ……………………………………………………………………………………
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6. Use the diagrams X and Y shown below to answer questions that follow
Ovum
X Y
a) State how the parts labelled B and D adapt the cell in diagram X to swimming
i) B ……………………………………………………………………………………..
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ii) D …………………………………………………………………………………….
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b) i)Name the part of the female reproductive system where the process shown in Y takes
place (1mk
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ii) Explain how the organelle found in region A of the cell shown in X facilitates the
interaction of cells represented in X and Ovum as seen in Y (2mks
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7. James counted 12 cells under a light microscope with a field of view of radius 3mm.
Determine the diameter of one cell in micrometers (3mks
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8. The following photograph is of a common travelling animal
a) Explain how part labelled Q adapts the animal to its life in the desert? (2mks
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b) Give a reason why the animal shown above belongs to class Mammalia (1mk
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c) State the expected feature in the kidneys of the animal shown above in terms of the
following: (2mks
i) Number of nephrons …………………………………………………………………
ii) Length of Loop of Henle ……………………………………………………………
9. A section of a chromosome was found to have 333 nucleotides. State the number of the
following in relation to this section. (3mks
a) Number of Nitrogenous bases ………………………………………………………….
b) Number of codons ……………………………………………………………………...
c) Number of Amino acids coded for ……………………………………………………..
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10. Use the illustration shown below to answer the questions that follow
a) Name the type of tissue illustrated above (1mk
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b) Why is A likely to be found in the mammalian lungs? (1mk
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c) How does tissue labelled D adapt the following parts of the human body to their
functions
i) Oviduct (1mk
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ii) Trachea (1mk
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11. State TWO principles of the Theory of Special Creation in relation to origin of life.
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12. James and Mary made a decision to get married but before that, they approached a qualified
medical doctor for genetic counseling.
a) Give TWO reasons why this was important (2mks
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b) State TWO ways the medical doctor did the genetic diagnosis (2mks
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13. a) Name the respiratory surfaces in the following organisms (2mks
i. Amoeba ……………………………………..……………………………………...
ii. Nile perch fish …………………………………..………………………………….
b) State the expected structural differences between roots of hydrophytes and those of
mesophytes in terms of the following features (3mks
Feature Hydrophyte Mesophyte
Type of Roots
Cuticle
Root hairs
14. Name the deficient nutrient in the following disorders (2mks
a) Goitre ………………………………………………………………………………….
b) Scurvy ………………………………………………………………………………….
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15. The following diagram is an illustration of the mammalian skin. Use it to answer the
questions that follow.
M
Q
a) Name the muscle important in the functioning of part labelled N (1mk
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b) State the importance of P to the functioning of part N (2mks
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c) Explain how part M helps lower body temperature on a hot day. (2mks
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16. Differentiate between the terms community and population as used in ecology. (2mks
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17. Study the life cycle shown below and answer the questions that follow.
a) i) Identify the life cycle shown above (1mk
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ii) Give a reason for your answer in ai) above (1mk
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b) Explain how the prothoracic gland is important in the life cycle above (2mks
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18. In a metabolic reaction 2 molecules of Oxygen were used to oxidise a food substance and
in the process 18 molecules of Carbon (IV) Oxide was released.
a) Calculate the Respiratory Quotient for this reaction (2mks
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b) Give a reason why this reaction represents anaerobic respiration (1mk
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19. a) Give a reason why active immunity is advantageous. (1mk
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b) Josephine had an accident leading to damaged tissue and the medical doctors advised
for use of autografts but not xenograft for an operation to replace damaged tissue. Explain
(2mks)
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20. Use the diagram shown below to answer questions that follow.
a) Give TWO reasons to show that the flower above is a wind pollinated flower (2mks
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b) State TWO significance of seed dormancy (2mks
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21. The body temperature of a bobcat and a snake were studied over time against the
ambient/surrounding temperature and plotted as shown in the graph below.
a) Account for the observation shown in the graph (2mks
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b) Give TWO disadvantages a snake experiences as a result of the temperature changes
shown in the graph above (2mks
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22. Describe the mechanism of stomata opening using the starch-sugar inter-conversion theory
(4mks
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23. A couple had the following as the appearance of their Red Blood Cells under a light
microscope
a) Which survival advantage does the couple have over those with normal Red Blood
Cell appearance? (1mk
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b) The couple had children. Write down all the probable genotypes of their children. Use
letters A and B to represent the alleles (1mk
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