Which of the following are the post-transcriptional events in an eukaryotic cell? A. Transport of pre-mRNA to cytoplasm prior to splicing B. Removing of introns and joining of exons C. Addition of methyl group at 5′ end of hnRNA. D. Addition of adenine residues at 3′ end of hnRNA. E. Base pairing of two complementary RNAs. Choose the correct answer from the options given below:
Answer: (D) B, C, D only. Answer: (D) B, C, D only.
- A.B, C, E only
- B.C, D, E only
- C.A, B, C only
- D.B, C, D only✓
Correct Answer
(D) B, C, D only
Solution & Explanation
Answer: (D) B, C, D only. Post-transcriptional processing of hnRNA comprises splicing (removing introns, joining exons), capping (adding methyl guanosine at the 5' end) and tailing (adding adenylate residues at the 3' end); A is false because splicing occurs in the nucleus before transport, and E (base pairing of two complementary RNAs) describes RNA interference, not processing. NCERT Ch 5, p.95, lines 009-016: "a process called splicing where the introns are removed and exons are joined... 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... that is transported out of the nucleus for translation."