A mutant E. coli strain, grown under conditions that normally induce the lac operon, does not produce ß-galactosidase. What is a possible genotype of the cells? A) lacI⁺ lacP⁺ lacO⁺ lacZ⁺ lacY^- lacA⁺ B) lacI⁺ lacP⁺ lacO^c lacZ⁺ lacY⁺ lacA⁺ C) lacl⁺ lacP⁺ lacO⁺ lacZ⁺ lacY⁺ lacA⁺ D) lacI⁺ lacP^- lacO⁺ lacZ⁺ lacY⁺ lacA⁺ E) lacI^- lacP⁺ lacO^- lacZ⁺ lacY⁺ lacA^-

Question

Quizplus · Accepted Answer

The mutation in the promoter (lacP^-) prevents RNA polymerase from binding, thus inhibiting transcription of the lac operon, including the lacZ gene that encodes ß-galactosidase.

A Mutant E