(a(i))[4]
Describe the role of the following enzymes in genetic engineering using plasmids: • restriction endonuclease • DNA ligase • DNA polymerase • reverse transcriptase.
(a(ii))[3]
Explain why a promoter, in addition to the desired gene, is often moved into an organism.
(b)[3]
Comment on whether a bacterium will produce the insulin polypeptide if it contains plasmid X or plasmid Y or plasmid Z, and explain why you chose that answer.