Identify the correct statement.
- Split gene arrangement is characteristic of prokaryotes
- In capping, methyl guanosine triphosphate is added to the 3' end of hnRNA
- RNA polymerase binds with Rho factor to terminate the process of transcription in bacteria
- The coding strand in a transcription unit is copied to an mRNA
Answer
(3) RNA polymerase binds with Rho factor to terminate the process of transcription in bacteria
Solution
(1) Incorrect – split genes (exons interrupted by introns) are characteristic of eukaryotes, not prokaryotes.
(2) Incorrect – as per NCERT, in capping an unusual nucleotide (methyl guanosine triphosphate) is added to the 5' end of hnRNA; adenylate residues (poly-A tail) are added at the 3' end.
(3) Correct – as per NCERT, in bacteria RNA polymerase associates transiently with the initiation factor σ to initiate and with the termination factor ρ (rho) to terminate transcription.
(4) Incorrect – the template strand is copied into mRNA; the coding strand has the same sequence as mRNA (T in place of U) and is not copied.
Answer: (3)