Question

A promoter is ______.

	a.	a sequence in DNA that brings RNA polymerase near the site for transcription
	b.	one or more eukaryotic proteins that bind to DNA near the start of a gene
	c.	a protein that associates with bacterial RNA polymerase to help it bind to DNA
	d.	a sequence in RNA that promotes the release of RNA polymerase from DNA

Which of the following statements best describes the promoter of a protein-coding gene?

	a.	A site where many different proteins will bind
	b.	A site in DNA that recruits the RNA Polymerase
	c.	Part of the RNA molecule itself
	d.	A site found on the RNA polymerase

Answer 1

Question 1:-

The right option is option (A) A sequence in DNA that brings RNA polymerase near the site for transcription.

Explanation:-

Promoter in a gene is an upstream element. This means that it is found before the site of a gene where Transcription start, so it is a DNA sequence and isn't a Protein or RNA part. Promoters are found in both the prokaryotes as well as Eukaryotes and only when they are present, Transcription can take place. Thus they can turn the Gene on or off.

Question 2:-

The right option is option (B) A site in DNA that recruits the RNA polymerase.

Explanation:-

It is the promoter which is responsible for the binding of RNA polymerase to the DNA and initiating the transcription. Proteins, called Transcription factors bind to it and they recruit the RNA polymerase.

This sounds like option A too, but in prokaryotic cells, promoter don't interact with Transcription factors, so universally as a common unit, promoter is the DNA sequence which recruits RNA polymerase.