Question

Read the following and answer from given below:

The process of copying genetic information from the template strand of DNA into RNA is called transcription. It is mediated by RNA polymerase. Transcription takes place in the nucleus of eukaryotic cells. In transcription, only a segment of DNA and only one of the strands is copied into RNA.

Which enzyme helps in tailing or polyadenylation?

Options

• Poly-A polymerase

• Exonucleases

• RNA polymerase I

• RNA polymerase II

Answer 1

Poly-A polymerase

Explanation:

Tailing or polyadenylation is the addition of a poly-A tail at the 3' end of an mRNA with the help of poly-A polymeras. The poly-A tail contains adnate residues (about 200-300 residues). Polyadenylation is thought to protect the 3' end from degradation by exonucleases.