Bacteria transformed with plasmids are plated on growth medium containing ampicillin and X-gal. White colonies on the plate contain bacteria with a ____ plasmid, meaning the lacZ⁺gene is ____. A) recombinant; deleted from the plasmid B) nonrecombinant; intact C) recombinant; intact D) nonrecombinant; disrupted by the inserted DNA fragment E) recombinant; disrupted by the inserted DNA fragment

Question

Quizplus · Accepted Answer

White colonies indicate that the lacZ gene has been disrupted by the insertion of a DNA fragment, which prevents the bacteria from metabolizing X-gal into a blue product. This disruption occurs in recombinant plasmids where the foreign DNA is inserted into the lacZ gene, thus the correct answer is that the plasmid is recombinant and the lacZ gene is disrupted by the inserted DNA fragment.

Bacteria Transformed with Plasmids Are Plated on Growth Medium Containing