When a recombinant dNA is inserted within the coding sequencing of an enzymes, `beta`-galacttosidase

Options

A. This result into inactivation of the enzyme
B. This is called insertional inactivation
C. In the presence of insertion, the colonies do not produce any colour
D. All of these

Answer

D

Explanation

The selectable markers are developed which differentiate recombinants from non – recombinant on the basis of their ability to produce colour in the presence of a chromogenic substrate.
In this method a recombinant DNA is inserted within the coding sequence of enzyme galactosidase. This result into the activation of the enzyme called insertional inactivation. The bacterial colonies whose plasmid do not have an insert, produce blue colour but others do not produce any colour when grown on a chromogenic substrate