Question

Choose the incorrect statement with respect to host used.

(a) The host must carry mutation for the gene of interest

(b) The host should not contain restriction enzymes

(c) The host if having restriction enzymes, then the incoming DNA should not be methylated

(d) The host should be deficient in recombination

This question was addressed to me in class test.

Question is taken from Screening by Expression In Vivo topic in division Screening Libraries of Genetic Engineering

Answer 1

The correct option is (c) The host if having restriction enzymes, then the incoming DNA should not be methylated

The best I can explain: The host used must carry the mutation for the gene of interest. The host must not contain restriction enzymes. If the host is having restriction enzymes then the incoming DNA must be methylated. If the incoming DNA is not methylated, then it would be cleaved by restriction enzymes. The host should also be deficient in recombination otherwise it would be difficult to get it.