Biology 9700 · AS & A Level · Genetic technology applied to medicine

Genetic technology applied to medicine — practice question

Haemophilia is a disorder of blood clotting in humans that results from a mutant allele on the X chromosome. Table 4.1 sets out a comparison between the two forms of haemophilia: haemophilia A and haemophilia B.
(a)[4]

Genetic engineering is applied to produce recombinant human proteins for the treatment of people with haemophilia A and haemophilia B. Outline the principles of genetic engineering.

(b(i))[3]

Using Table 4.1 and the introduction to (a), assess which form of haemophilia, A or B, scientists ought to attempt to treat first and whether haemophilia should be tackled with gene therapy at all. Justify your answer.

(b(ii))[2]

In gene therapy trials for haemophilia, the gene coding for the clotting factor must be inserted together with a promoter. Explain why a promoter must be added as well as the required gene.

(b(iii))[2]

Some people involved in gene therapy trials have previously been exposed naturally to the virus that carries the functional gene, so their blood already contains antibodies against the virus. Predict how this will influence the success of the gene therapy treatment.

(c)[2]

Gene editing is a newer way of changing DNA. Some scientists are investigating the use of gene editing, rather than inserting a functional gene, to treat haemophilia. State two possible advantages of using gene editing as a method of treating haemophilia.

Worked solution & mark scheme

This 13-mark question has a full step-by-step worked solution and mark scheme. One marking point: DNA is manipulated so that an organism's characteristics are changed

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