Question

What are the different types of RNA J Polymerases found in the nucleus of eukaryotes? State function of each of them.

Answer 1

(a) RNA polymerase-I : It is used to transcribes 5.8s, 18s and 28s RNA. 

(b) RNA polymerase-II : It is involved in the transcription of MRNA precursors. It also catalyzes the formation of small nuclear RNA's and mRNA. 

(c) RNA polymerase-III : It is used to transcribe transfer RNA (tRNA), some ribosomal RNA.

Answer 2

Eukaryotic cells contain three distinct nuclear RNA polymerases that transcribe different classes of genes . Protein-coding genes are transcribed by RNA polymerase II to yield mRNAs; ribosomal RNAs (rRNAs) and transfer RNAs (tRNAs) are transcribed by RNA polymerases I and III.