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3 marksGenetic Concepts

CSEC Biology · May/June 2005 · Paper 2 · Question 5(b)

There are various blood group systems, with the ABO system being the most common. In the ABO system, there are FOUR different blood groups, but only THREE alleles determine these blood groups.

Account for the fact that in the ABO system, although there are FOUR different blood groups in existence, only THREE alleles determine these blood groups.

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Other parts of this question

  1. 5(a)(i)Using the chart in Figure 6 above, state the genotypes of family members, 1, 2 and 6.[3 marks]
  2. 5(a)(ii)Identify the type of variation involved in the inheritance of earlobe size in humans shown in Figure 6 above.[1 mark]
  3. 5(a)(iii)Give ONE reason for the importance of variation among living things.[1 mark]
  4. 5(c)Name ONE inherited disease.[1 mark]
  5. 5(d)How do the treatment and control of an inherited disease differ from the treatment and control of a deficiency disease?[4 marks]

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