Assertion: Methyl guanosine triphosphate is added to the 3’ end of hnRNA (pre-mRNA) during the process known as capping.

Reason: Capping is a post-transcriptional modification in eukaryotic mRNA processing, where an unusual nucleotide (methyl guanosine triphosphate) is added to the 5'-end of hnRNA.

Assertion is false, but Reason is true.

The correct answer is Option (4) –Assertion is false, but Reason is true.

Methyl guanosine triphosphate is added to the 5’ end of hnRNA (pre-mRNA) during the process known as capping.

In eukaryotes the primary transcripts contain both the exons and the introns and are non-functional. Hence, it is subjected to a process called splicing where the introns are removed and exons are joined in a defined order. hnRNA undergoes additional processing called as capping and tailing. Capping is a post-transcriptional modification that occurs in eukaryotic mRNA processing. In capping an unusual nucleotide (methyl guanosine triphosphate) is added to the 5'-end of hnRNA. In tailing, adenylate residues (200-300) are added at 3'-end in a template independent manner. It is the fully processed hnRNA, now called mRNA, that is transported out of the nucleus for translation.