SECTION A (40 Marks)
Answer all questions in this section in the spaces provided.
1. In human beings, a downward pointed frontal hairline (“windows peak”) is a heritable trait. A person with windows peak always has at least one parent who has this trait; where as persons with frontal hairline may occur in families in which one or even both parents have windows peak. Using W and w to symbolize genes for this trait
(a) Determine the F1 generation if a homozygous windows peak male parent is married to a homozygous frontal hairlined female parent (4mks)
(b) State two causes of variations (1mk)
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c) Name two sex linked genetic disorders affecting human females and males (2mks)
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(d) What is genome
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2. The diagram below shows an organism obtained from an aquatic ecosystem
(a) State the kingdom in which the organism belongs. (1mk)
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(b) Name the parts labeled (1mk)
B
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Y (1mk)
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(c) State the functions of the following parts
A (1mk)
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X (1mk)
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Z (1mk)
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(d)Explain briefly why the organism is described as eukaryotic (2mk)
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3a) The diagram below shows some of the features of a synovial joint. Study the diagram carefully and answer the questions that follow.
(a) Name the type of synovial joint. (1 mark)
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(b) Name the parts labeled J, and L (2 marks)
J …………………………………………………………………………………………
L ………………………………………………………………………………………..
(c) State two roles of the part labeled L. (2 marks)
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(d) Suggest one advantage of this type of joint. (1 mark)
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b) State how the following tissues are adapted to provide mechanical support in plants (2mks)
i) Parenchyma
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ii) Collenchyma
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4. A student set up an experiment using soaked and dry seeds as shown below
a) State the objective of this experiment (1mk)
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b) State the observations made in each of the flask after 24 hours (2mks)
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c) Account for the observation made in (b) above (2mks)
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d) Suggest why vacuum flasks were used in this experiment (1mk)
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e) What alteration would you make in the set-up to make the results more reliable (1mk)
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f) Why should the seeds be washed with antiseptic/10% formalin? (1mk)
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5 a) Explain how the following meristematic tissues contribute to growth of higher plants
i) Vascular cambium (2mks)
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ii) Cork Cambium (2mks)
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b) The diagram below shows a life cycle of a cockroach
a) Name the hormone that would be at high concentration during.
(i) First week (1mk)
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(ii) Second week (1mk)
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b) Name the structure that produces hormone in a (ii) above (1mk)
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c) Name the series of stages through which the nymph undergoes to reach adult stage (1mks)
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SECTION B (40 Marks) Kapsabet Boys 2022
Answer question 6 (Compulsory) and either question 7 or 8 in the spaces provided.
6. The menstrual cycle is a sequence of events repeated monthly in the female production system. The table below shows the concentration of oestrogen and progesterone hormones and body temperatures of female against time.
| Time in days | Oestrogen mg/100cm of blood | Progesterone mg/100cm3 of blood | Temperature in 0oc |
| 1 | 20 | 0 | 36.4 |
| 2 | 20.5 | 0 | 36.6 |
| 3 | 25 | 0 | 36.7 |
| 4 | 27.5 | 0 | 36.8 |
| 5 | 30 | 0 | 36.7 |
| 6 | 32.5 | 0 | 36.6 |
| 7 | 35 | 0 | 36.8 |
| 8 | 40 | 0 | 36.7 |
| 9 | 48 | 0 | 36.6 |
| 10 | 56 | 0 | 36.8 |
| 11 | 64 | 0 | 36.7 |
| 12 | 72 | 0 | 36.6 |
| 13 | 80 | 0 | 36.4 |
| 14 | 170 | 20 | 36.3 |
| 15 | 140 | 50 | 36.6 |
| 16 | 80 | 80 | 37.0 |
| 17 | 70 | 130 | 37.2 |
| 18 | 65 | 170 | 37.0 |
| 19 | 60 | 160 | 37.1 |
| 20 | 65 | 150 | 37.15 |
| 21 | 130 | 130 | 37.2 |
| 22 | 140 | 110 | 37.1 |
| 23 | 130 | 90 | 37.0 |
| 24 | 100 | 70 | 37.1 |
| 25 | 80 | 50 | 37.2 |
| 26 | 60 | 20 | 37.0 |
| 27 | 20 | 0 | 36.4 |
a). Using the same axis draw graphs of oestrogen and progesterone against time/days (8mks)