18. Name the particular technic in biotechnology whose steps are shown in the figure . Use the figure to summarise the technique in three steps.
19. 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
(a) Mention the mechanism and the steps involved in the above experiment.
(b) How is it advantageous over simultaneous plating on two plates having different antibiotics ?