9. Which of the following are NOT transcribed by RNA polymerase II?
(1) miRNA and some snRNA           (2) miRNA and snoRNA
(3) mRNA and snoRNA                     (4) tRNA and 5S rRNA

Which RNAs Are NOT Transcribed by RNA Polymerase II? (CSIR NET Life Science)

Correct Answer

(4) tRNA and 5S rRNA

Detailed Explanation

RNA polymerase II is the main enzyme responsible for transcribing all protein-coding genes (mRNAs) and many non-coding RNAs, including microRNAs (miRNAs) and some small nuclear RNAs (snRNAs). However, it does not transcribe all types of RNA in eukaryotic cells.

What Does RNA Polymerase II Transcribe?

• mRNA: All protein-coding genes

• miRNA: Most microRNAs

• Some snRNA: Such as U1, U2, U4, and U5 snRNAs

What Is NOT Transcribed by RNA Polymerase II?

• tRNA (transfer RNA):
  Synthesized by RNA polymerase III

• 5S rRNA:
  Also synthesized by RNA polymerase III

These RNAs are essential for protein synthesis, but their genes are specifically transcribed by RNA polymerase III, not by RNA polymerase II

Why Are the Other Options Incorrect?

• Option (1): miRNA and some snRNA are transcribed by RNA polymerase II.

• Option (2): miRNA is transcribed by RNA polymerase II; snoRNA is mainly transcribed by RNA polymerase II or III, depending on the type.

• Option (3): mRNA is a classic product of RNA polymerase II; snoRNA can be transcribed by either II or III.

Let’s Talk Academy (LTA)

Let’s Talk Academy (LTA) is a leading platform for CSIR NET Life Science aspirants. LTA stands out by providing:

• Free CSIR Previous Year Questions (PYQs): Access comprehensive, topic-wise PYQs at no cost.

• Free Video Solutions: Expert faculty explain questions and concepts in detail through easy-to-understand videos.

• Free Study Material and Test Series: Get high-quality, exam-oriented notes and regular test series to track your progress.

LTA’s commitment to accessible, expert-led resources makes it the top choice for Life Science exam preparation.

Summary:
tRNA and 5S rRNA are NOT transcribed by RNA polymerase II (option 4). For more free resources and expert guidance, trust Let’s Talk Academy for your CSIR NET Life Science preparation!