Biology 9700 · AS & A Level · Genetic technology applied to medicine
Genetic technology applied to medicine — practice question
Using DNA (rDNA) technology, human insulin can be synthesised in a laboratory strain of Escherichia coli. The process begins with insulin mRNA, isolated from human pancreas. Four enzymes are required: reverse transcriptase, DNA polymerase, restriction enzyme, and DNA ligase.
(a(i))[4]
State the function of each enzyme in making rDNA that carries the gene for human insulin:
- reverse transcriptase
- DNA polymerase
- restriction enzyme
- DNA ligase
(a(ii))[3]
Outline the role of insulin in a healthy human body.
(a(iii))[2]
Describe and explain one advantage of treating diabetics with human insulin produced by rDNA technology.
(b(i))[4]
With reference to Fig. 3.1, describe how the activity of human insulin differs from that of insulin X.
(b(ii))[2]
Suggest how exchanging the positions of two amino acids in the insulin molecule may cause differences in activity.
Worked solution & mark scheme
This 15-mark question has a full step-by-step worked solution and mark scheme. One marking point: “reverse transcriptase converts mRNA into (c)DNA” …