Question

Predict the phenotype of an operator mutant (O c) which would prevent the binding of the repressor.
a.The lac genes would be expressed efficiently only in the absence of lactose. b.The lac genes would be expressed efficiently only in the presence of lactose. c.The lac genes would be expressed continuously. d.The lac genes would never be expressed efficiently.

Answer 1

Answer:

c.The lac genes would be expressed continuously.

Explanation:

The correct response is (c) The lac genes would be expressed continuously because the active repressor cannot bind to the mutant O c operator. Accordingly, the repressor will not be able to inhibit RNA polymerase from binding to the lac promoter, producing the lac operon to be transcribed continuously or constitutively. Formerly again the level of appearance is inversely proportionate to the level of glucose already present.