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

Genetic technology applied to medicine — practice question

Haemophilia A and haemophilia B are widespread inherited blood-clotting disorders. Haemophilia A is a sex-linked genetic disorder that affects about 1 in 20000 males worldwide. It results from a recessive allele of a gene that codes for a clotting factor and causes excessive bleeding. There is still no cure, although the symptoms of haemophilia can be managed by transfusing a clotting factor to slow the bleeding.
(a)[2]

State how genetic screening could lower the number of cases of haemophilia.

(b(i))[2]

Outline the objectives of gene therapy.

(b(ii))[1]

Suggest why haemophilia A is suitable for treatment using gene therapy.

(c(i))[2]

With reference to Table 4.1, suggest why gene therapy using the $F9$ gene has been more successful than gene therapy using the $F8$ gene.

(c(ii))[3]

Table 4.2 compares two vectors commonly used in gene therapy. With reference to Table 4.2, explain the advantages and disadvantages of choosing adenovirus instead of retrovirus as a vector.

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