Question

In an experiment you use RNA polymerase without its sigma factor for transcription. What will be the result that you observe?

(a) More transcription

(b) Less transcription

(c) More specific transcription

(d) More random transcription

I had been asked this question during an online interview.

Question is from Transcription in Prokaryotes : Initiation topic in division Gene Expression : Transcription Prokaryotes of Cytogenetics

Answer 1

The correct option is (d) More random transcription

The explanation is: Sigma subunit is responsible for recognizing the transcription start site. In its absence the RNA pol will transcribe at non-specific random sites. Sigma plays no role in the rate of transcription so there is no chance in transcription rate in its absence.