A growth curve is shown for E. coli cultivated in media containing lactose and glucose. At which points on the growth curve is the lac operon transcribed? Please select all that apply.

Question

Quizplus · Accepted Answer

The lac operon is only transcribed in the presence of lactose or lactose analogs, which induces the lac repressor to release from the operator site on the DNA. In this growth curve, lactose is only added at point B when the glucose is consumed, so it is only at this point that the lac operon is being transcribed. Therefore, the correct answer is B.

A Growth Curve Is Shown for E