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12 marksAspects of Genetic Engineering

CAPE Biology Unit 1 · May/June 2021 · Paper 2 · Question 2(c)(ii)

A 2017 study used gene therapy to treat sickle-cell anaemia. Figure 3 shows the percentage of sickled red blood cells under low oxygen conditions for a treated patient at 6 and 12 months, along with five control subjects.

Discuss three challenges that may limit the success of gene therapy as an effective medical treatment for diseases.

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Other parts of this question

  1. 2(a)(i)Provide labels on Figure 2 to identify the components labelled S, T, U, and V.[5 marks]
  2. 2(a)(ii)Draw a circle around a section of Figure 2 to identify a single nucleotide.[1 mark]
  3. 2(a)(iii)State how two nucleotides in a DNA molecule are held together.[1 mark]
  4. 2(a)(iv)Outline the roles of messenger RNA (mRNA) and transfer RNA (tRNA) in polypeptide synthesis in eukaryotic cells.[4 marks]
  5. 2(b)(i)Name the type of change in the gene that causes the production of abnormal haemoglobin in individuals with sickle-cell anaemia.[1 mark]
  6. 2(b)(ii)Outline how low oxygen saturation causes red blood cells to change into a sickle shape.[3 marks]
  7. 2(c)(i)Analyse the success of the gene therapy treatment for sickle-cell anaemia using the data presented in Figure 3.[3 marks]

More practice: the rest of this paper · more Aspects of Genetic Engineering questions · all CAPE Biology Unit 1 past papers