Question

ccdB gene is used at times. Choose the correct statement with respect to this gene.

(a) It is a control of cell birth gene

(b) It is activated in complex vectors to increase the fraction of recombinants

(c) If intramolecular ligation takes place this protein is released

(d) It is often regarded as control of cell death and birth gene

The question was posed to me in unit test.

The question is from Modifications in Cloning Methods, Linkers,  Adaptors and Cassettes in chapter Simple Cloning of Genetic Engineering

Answer 1

Correct option is (b) It is activated in complex vectors to increase the fraction of recombinants

Easiest explanation: It is an approach to increase the fraction of recombinants. There are some genes which are activated on the self ligation of the molecules and are responsible for the death of host molecules. ccdB is control of cell death gene and its protein is responsible for killing the host molecules when intramolecular ligation takes place.