STAREHE BOYS' CENTRE MINI-MOCK EXAMINATION 2001 231/1 BIOLOGY PAPER 1 THEORY 2½ HOURS NAME: __________________________________________________ SET: _______

SECTION A: (40 MARKS) Answer all the questions in this section in the spaces provided 1. Give two reasons why organisms are classified. {2 marks} i) ii) 2. If the nerve supply to the heart of a mammal is severed, the rythmic heart contraction and relaxation will still go on and the heart continues to beat. Explain why this is so. {2 marks} 3. List two features that can be used to classify the Euglena as a plant. {2 marks} i) ii) 4. Write down three differences between phloem and xylem. {2 marks} Phloem Xylem i) ii) i) ii) 5. Suggest 3 characteristics best suited to growing in an area which has sandy soil. {3 marks} a) b) c) 6. State 3 ways by which the ileum is adapted for its functions. {3 marks} a) b) c) 7. Explain what will happen if you slept in a poorly ventilated room with a burning charcoal jiko. {2 marks} 8. Name two biological significance of diffusion in animals. {2 marks} a) b) 9. The sebacious glando produce a fluid called sebum. a) What is its effect on the skin? {1 mark} b) Name the protection it gives to the skin. {1 mark} SECTION B: (40 MARKS) Answer all questions in the space provided 10(a) Draw a neat and well labelled diagram of the palisade cell. {4 marks} (b) How is it adapted for its functions. {1 mark} 11. The diagram below represents a mature bread mould. a) Name the structures P, Q, R. {1½ mark} b) What is the functions of structure P? {1 mark} c) State two differences between the reproduction in a common mould and a garden pea. {2 marks} Common mould Garden pea i) ii) i) ii) d) Write any two economic importance of moulds. {2 marks} i) ii) 12. The graph below shows heat loss and heat production in a mammal. a) At what body temperature does the body lose as much heat as it produce? {1 mark} b) Account for the relationship between heat loss and heat production above 40oC. {3 marks} c) Why were the readings for this experiment not taken at temperatures above 40oC%. {2 marks} d) How does sweating help the body to lose heat. {2 marks} 13. In bean plants the gene for tall plants (T) is dominant to that of short plants (t). a) Work out a crossing of homozygous tall and homozygous short. {3 marks} b) What are the phenotypic and genotypic ration of the cross between the offsprings of (a) above. {2 marks} c) In genetic analysis of what value is “test cross”? {1 mark} 14(a) Outline 3 factors that affect the rate of respiration in animals. {3 marks} i) ii) iii) b) What do you understand by: i) Inspiratory reserve volume. {1 mark} ii) Lung capacity. {1 mark} SECTION C: (40 MARKS) Answer question 15 (compulsory) in the spaces provided and one other question from this section. 15. In an ecological study a certain insect population and that of predators was estimated in a certain grassland area over a period of one year. Months J F M A M J J A S O N D No. of insects 80 20 12 24 200 600 120 16 10 30 180 400 No. of predators 10 8 2 4 16 30 10 4 2 2 5 20 Amount of rainfall 20 0 55 350 500 250 12 10 25 190 240 30 a) Using a common scale plot a bar chart to represent rainfall and line graph to represent population of the insects to show the relationship between rainfall and the insects population. {8 marks} b) Explain the relationship between the insect population and that of predators. {3 marks} c) Suggest what happens to the insects population during dry months. {2 marks} d) Suggest what happens to the predators population during the dry months. {2 marks} e) From this study, what is the trophic level of i) the predators. {½ mark} ii) the insects. {½ mark} iii) the grass in the study area. {½ mark} f) State the method that could have been used to estimate the population of i) predators. {½ mark} ii) insects. {½ mark} iii) grass. {½ mark} g) Suggest 2 difficulties that could been encountered in such a study. 16(a) Outline the functions of a mammalian placenta. {8 marks} (b) Using diagrams, describe the different stages of oogenesis in human beings. {12 marks} 17. With a help of a diagram explain the process involved in absorption and movement of water through the plant, from the soil to the atmosphere. {20 marks}