If a researcher moves the repressor gene (lacI) and its promoter, to a position at some several thousand base pairs away from its normal position, which of the following describes the most likely effect on the lac operon?
A) The repressor will no longer bind to the operator.
B) The repressor will no longer bind to the inducer.
C) The lac operon will be expressed continuously.
D) The lac operon will function normally.

Question

Quizplus · Accepted Answer

The lac operon's functionality is primarily determined by the interaction between the repressor protein and the operator region. Moving the lacI gene and its promoter does not inherently alter the ability of the repressor protein to be synthesized or its ability to bind to the operator. Thus, as long as the repressor can still be produced and can reach the operator, the operon can function normally. The physical distance in the DNA between the lacI gene and the operon does not directly affect the interaction between the repressor protein and the operator, thanks to the nature of DNA looping and protein diffusion within the cell.

If a Researcher Moves the Repressor Gene (LacI) and Its