Question

In the processing of hnRNA in eukaryotic cell, the primary transcripts are processed in the following sequence.

Options

• Splicing, Capping, Tailing

• Tailing, Capping, Splicing

• Splicing, Tailing, Capping

• Splicing, Tailing, Capping

Answer 1

Splicing, Capping, Tailing

Explanation:

In eukaryotic hnRNA (pre-mRNA) processing:

1. Splicing → Removal of introns and joining of exons.
2. Capping → Addition of a 5′ methylguanosine cap to protect RNA from degradation and help in ribosome binding.
3. Tailing (Polyadenylation) → Addition of a poly-A tail at 3′ end for stability and export from nucleus.