If you wanted to block transcription of a group of functionally related genes in a prokaryote,you could place an obstacle
A)upstream of both the promoter and operon.
B)downstream of both the promoter and operon.
C)place an obstacle downstream of the promoter,but upstream of the operon.
D)place an obstacle upstream of the promoter,but downstream of the operon.

Question

Quizplus · Accepted Answer

Placing an obstacle downstream of the promoter would completely block transcription of all genes in the operon, while placing an obstacle upstream of the promoter would prevent the binding of RNA polymerase and thus prevent transcription of any genes in the operon. However, placing an obstacle downstream of the promoter but upstream of the operon would specifically block only the transcription of the genes in that operon, allowing transcription of other operons to continue. This approach would effectively and specifically block the transcription of the functionally related genes in question.

If You Wanted to Block Transcription of a Group of Functionally