(a) We will use following method that help in selection of recombinant colonies from non recombinant ones.
(1) We will put this transgenic bacteria into ampicillin medium transformant will grow in it.
(2) Now this transforment growing bacteria (Recombinant plasmid are present in it) transfer into lactose and X-gal chromogen containing medium. If colour does not appears this indicates recombinant colonies but colour appears this indicates non recombinant.
(b) Due to insertional inactivation α-galactosidase gene is inactivated so, it does not produce lactase enzyme that convert X-gal chromogen into blue colour that, why colour does not appears in recombinant ones.
