A bacterial operon is responsible for the production of the biosynthetic enzymes needed to make the hypothetical amino acid tisophane (tis). The operon is regulated by a separate gene, R. The deletion of R causes the loss of enzyme synthesis. In the wild-type condition, when tis is present, no enzymes are made; in the absence of tis, the enzymes are made. Mutations in the operator gene (O⁻) result in repression regardless of the presence of tis. Is the operon under positive or negative control? Propose a model for (a) repression of the genes in the presence of tis in wild-type cells and (b) the mutations.

Hello everyone here We have a question telling us one type of mutant of Black Hill is called a super suppressor. And the question is, what is its role in repressing the lack chaperon? The mute or no black ill hinders the repressor polyp peptide from binding to lactose. So this means whether the lactose is present or not. The repressor polyp peptide will bind to the operator and this will prevent the lack operations expression. So our answer here is D it prevents the repressor protein from binding to the inducer. Thank you for watching. Bye!