1 (a) What is meant by the term wilting? (1 mark)
(b) Explain how an increase in temperature affects the rate of active transport. (2 marks)
2 The diagram below represents a cell as seen under an electron microscope.
(a) Based on the diagram, state whether it represents an animal cell or a plant cell. (1 mark)
(b) Give two reasons for your answer in 2(a) above. (2 marks)
(c) Why is the palisade layer a tissue? (1 mark)
3 (a) State two external features found in the clas Mammalia only. (2 marks)
(b) Name the taxonomic unit that comes immediately after a phylum in classification. (1 mark)
4 (a) State two roles of mucus in the stomach. (2 marks)
(b) Explain how age determines a person's energy requirements (2 marks)
5 Describe how turgor pressure builds up (3 marks)
6 Using a microscope, a student counted 55 cells across a field of view whose diameter was 6000μm. Calculate the average length of the cells. Show your working. (2 marks)
7 Explain how the following forces contribute to the movement of water up the xylem vessels: (2 marks)
8. Construct a step in a dichotomous key using two leaves one with a serrated and the other with a smooth margin. (2 marks)
9 State one way in which each of the following is structurally adapted to its function:
(a)neurone; (2 marks)
(b)mitochondrion (2 marks)
10 How are lenticels adapted for gaseous exchange? (2 marks)
11. State the advantage of possessing blood group AB. (1 mark)
12 (a) A student collected an organism and observed the following features: simple eyes, four pair of legs and two body parts.
(i) State the class to which the organism belongs. (1 mark)
(ii) Give an example of an organism in this class. (1 mark)
(b) Name the kingdom to which plasmodium belongs. (1 mark)
13 State two characteristics of living organisms that are specific to plants. (2 marks)
14 Name the three end products of anaerobic respiration in plants. (3 marks)
15 State two reasons why accumulation of lactic acid leads to an increase in heart beat. (2 marks)
16 Name three mechanisms that ensure cross pollination takes place in flowering plants. (3 marks)
17 Name the flower part that produces gametes. (1 mark)
18 How is the human sperm cell structurally specialised? (2 marks)
19 State three factors in seeds that cause dormancy. (3 marks)
20 Explain the theory of evolution by natural selection. (2 marks)
21 (a) Explain the role of continental drift in evolution (3 marks)
(b) What is meant by the term organic evolution?
22 The diagram below illustrates a response by a certain plant.
(a) Name the type of response (1 mark)
(b) Explain how the response illustrated above occurs (3 marks)
23 The diagram below illustrates a defect in the eye.