Given below are the sequence of events in the production of human insulin by Eli Lilly. a) Preparation of two DNA sequences corresponding to chain A and B of human insulin. b) Production of chain A and B separately. c) Introduction of chains in plasmids of E.coli. d) Extraction of chain A and B combining them by creating disulphide bonds. Choose the correct sequence of events.

Step-by-step solution

In 1983, Eli Lilly, an American company, prepared two DNA sequences corresponding to A and B chains of human insulin (a). These sequences were then introduced into plasmids of E. coli (c). The modified E. coli produced chains A and B separately (b). Finally, chains A and B were extracted and combined by creating disulfide bonds to form functional human insulin (d). Thus, the correct sequence of events is (a), (c), (b), (d). Answer: (a), (c), (b), (d)