Question

During transcription in eukaryotes, RNA polymerase II synthesizes

• A. precursors of tRNA and snRNA
• B. precursors of mRNA, snRNA and microRNA
• C. precursors of rRNA
• D. all of the above

Answer 1

The correct option is B

precursors of mRNA, snRNA and microRNA

The correct option is B.

Explanation of correct option:

1. Only one form of an RNA transcript, pre-ribosomal RNA (or pre-rRNA), is synthesized by RNA polymerase I (pol I).
2. It acts as a precursor for the 18S, 5.8S, and 28S rRNAs.
3. RNA polymerase II (Pol II) is a catalytic enzyme that catalyzes the production of mRNAs and other specialized RNAs.
4. RNA polymerase III (Pol III) is responsible for the production of tRNAs, 5S rRNA, and a few other short specialized RNAs.
5. All three forms of RNAs are synthesized by a single type of RNA polymerase in prokaryotes (tRNA, rRNA, and mRNA).

Final answer: During transcription in eukaryotes RNA polymerase II synthesized precursors of mRNA, snRNA, and microRNA.