Which of the following environments would most likely lead to the transcription of the lactose operon?
A) The cyclic AMP level is high, and the lactose level is low.
B) The cyclic AMP and lactose levels are both high within the cell.
C) There is glucose but no lactose in the cell.
D) There is more glucose in the cell than lactose.
E) The cyclic AMP levels are low.

Question

Quizplus · Accepted Answer

The lactose operon is only transcribed when lactose is present and glucose is absent. However, the presence of high levels of cyclic AMP is also necessary for the activation of the lac promoter. Choice B is the only option where both lactose and cyclic AMP levels are high, indicating that the conditions are favorable for the transcription of the lactose operon.

Which of the Following Environments Would Most Likely Lead to the Transcription