RNA polymerase in a prokaryote is composed of several subunits. Most of these subunits are the same for the transcription of any gene, but one, known as sigma, varies considerably. Which of the following is the most probable advantage for the organism of such sigma switching?
A) It might allow the transcription process to vary from one cell to another.
B) It might allow the polymerase to recognize different promoters under certain environmental conditions.
C) It could allow the polymerase to react differently to each stop codon.
D) It could allow ribosomal subunits to assemble at faster rates.
E) It could alter the rate of translation and of exon splicing.

Question

Quizplus · Accepted Answer

Sigma switching allows RNA polymerase to recognize different promoters under certain environmental conditions, leading to the expression of specific genes needed for survival or adaptation. This allows for a dynamic response to changing conditions and enhances the fitness of the organism.

RNA Polymerase in a Prokaryote Is Composed of Several Subunits