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2 marksTransport Systems

CSEC Biology · January 2007 · Paper 2 · Question 4(e)

Persons living at very high altitudes where the air is rare (low oxygen concentration) have a larger number of red blood cells per unit volume of blood than those living at sea level.

Suggest why a person living at high altitudes requires a relatively large number of red blood cells.

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  1. 4(a)(i)Using only the letters P, Q and R label the structures on both cells that perform EACH of the following: a) Produce ATP (P) b) Synthesise protein (Q) c) Allow…[3 marks]
  2. 4(a)(ii)Using the letters S and T, label the structure on Cell 2 ONLY that performs EACH of the following functions: a) Converts light into chemical energy (S) b)…[2 marks]
  3. 4(b)(i)Name structure X shown in Cell 1.[1 mark]
  4. 4(b)(ii)Suggest one process which these cells will not be able to perform. Give a reason for your answer.[2 marks]
  5. 4(c)(i)What is likely to occur in Cells 1 and 2 of Figure 4 if they were placed in distilled water for over half-an-hour?[4 marks]
  6. 4(c)(ii)Explain why the changes in Cell 1 might be different from the changes in Cell 2 after half-an-hour in distilled water.[2 marks]
  7. 4(d)Although blood cells are in a watery medium (plasma) they do not absorb excessive amounts of water. Explain why this is so.[2 marks]

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