NEETZoologyMolecular Basis of Inheritance
In eukaryotes, there is a clear division of labour among different RNA polymerases for the transcription of various RNAs. Which of the following eukaryotic RNA polymerases is correctly matched with the primary transcript it synthesizes?
Options
- ARNA polymerase I – tRNA and snRNAs
- BRNA polymerase II – heterogeneous nuclear RNA (hnRNA)
- CRNA polymerase III – precursor of mRNA
- DRNA polymerase II – 28S, 18S and 5.8S rRNAs
Correct answer
B. RNA polymerase II – heterogeneous nuclear RNA (hnRNA)
Step-by-step solution
In eukaryotes, there is a clear division of labour among the three RNA polymerases in the nucleus. RNA polymerase I transcribes rRNAs (28S, 18S, and 5.8S). RNA polymerase II transcribes the precursor of mRNA, the heterogeneous nuclear RNA (hnRNA). RNA polymerase III is responsible for the transcription of tRNA, 5S rRNA, and snRNAs (small nuclear RNAs). Therefore, only RNA polymerase II is correctly matched with its primary transcript, hnRNA. Answer: RNA polymerase II – heterogeneous nuclear RNA (hnRNA)