In a bacterial culture, some of the colonies produced blue colour in the presence of a chromogenic substrate and some did not due to the presence or absence of an insert (rDNA) in the coding sequence of `beta` - galactosidase.
(a) Mention the mechanism and the steps involved in this experiment.
(b) How is it advantageous over simultaneous plating on two plates having different antibiotics?

In an experiment of recombinant DNA technology, in a bacterial culture some of the colonies produced blue colour in presence of a chromogenic substrate. Why?

During insertional inactivation, the presence of a chromogenic substrate gives blue coloured colonies if the plasmid in the bacteria does not have an insert. The blue colour is produced by the enzyme 1) α -glucosidase 2) restriction endonuclease 3) β -galactosidase 4) Taq polymerase

Read the given statements and select the correct option Statement 1 : In insertional inactivation, blue colour produced by bacterial colonies indicates that the plasmid does not have an insert into the bacterial genome. Statement 2: Presence of insert results into insertional inactivation of beta -galactosidase enzyme and the colonies do not produce any colour. A) Both statements 1 and 2 are correct B) statement 1 is correct but statement 2 is incorrect C) statement 1 is incorrect but statement 2 is correct D) Both statements 1 and 2 are incorrect