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2 marksNutrition in Living Organisms

CSEC Biology · May/June 2018 · Paper 2 · Question 1(a)(i)

Scientists are studying the survival of organisms in high-temperature desert habitats. They extracted protease, an enzyme for protein digestion, from microorganisms in a desert where daily temperatures exceed 50 °C, to investigate the effect of temperature on its activity.

State TWO precautions that they should take in carrying out this experiment.

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Other parts of this question

  1. 1(a)(ii)The results of their experiment are presented in Table 1. On the grid provided in Figure 1 on page 5, draw a graph to represent the results presented in Table…[4 marks]
  2. 1(a)(iii)From the graph in Figure 1, identify the optimum temperature for the protease activity.[1 mark]
  3. 1(a)(iv)Suggest ONE reason for the shape of the graph at less than 10 °C, TWO reasons for the shape of the graph between 10 and 55 °C, and ONE reason for the shape of…[4 marks]
  4. 1(a)(v)Describe a suitable procedure that the scientists could use to investigate the effect of pH on the activity of the protease enzyme.[3 marks]
  5. 1(b)(i)Name the parts labelled I, II, III and IV in Figure 2.[4 marks]
  6. 1(b)(ii)Describe how the structures named in (b)(i) help humans to regulate their body temperature.[4 marks]
  7. 1(c)Explain how changes in the epidermal cells of leaves help plants to conserve water during high temperatures.[3 marks]

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