The trp operon is known to operate by both negative repressible regulation of operator and attenuation. Which of the following statements does NOT support the reason as to why dual control exists to regulate the operon?
A) The repression alone is never complete, and some transcription can be initiated.
B) Combined mechanism provides a much finer tuning of tryptophan synthesis regulation.
C) Attenuation and repression allow the cell to more sensitively respond to the tryptophan level.
D) It is most likely due to the fact that the attenuation is the evolutionary relic, which by accident has remained.
E) Repression responds to the cellular levels of tryptophan, while attenuation responds to the number of tRNA charged with tryptophan.

Question

Quizplus · Accepted Answer

Attenuation is not considered an evolutionary relic; it is an active regulatory mechanism that works alongside repression to finely tune the response to tryptophan levels.

The Trp Operon Is Known to Operate by Both Negative