Question

Transfer RNA is transcribed by

• A. RNA Polymerase I
• B. RNA Polymerase II
• C. RNA Polymerase III
• D. RNA Polymerase IV

Hint:

RNA Pol I = Major rRNAs ($28S, 18S, 5.8S$); RNA Pol II = mRNA; RNA Pol III = tRNA and $5S$ rRNA.

Answer 1

The Correct Option is C

Step 1: Understanding the Concept:
Eukaryotic cells employ distinct nuclear RNA Polymerase enzymes specialized for specific transcript classes.

Step 2: Detailed Explanation:
The division of labor among eukaryotic RNA polymerases is:
1. RNA Polymerase I: Transcribes major ribosomal RNAs (28S, 18S, and 5.8S rRNAs).
2. RNA Polymerase II: Transcribes precursor mRNA (hnRNA), snRNAs, and microRNAs.
3. RNA Polymerase III: Transcribes transfer RNAs (tRNAs), 5S rRNA, and U6 small nuclear RNA.
4. RNA Polymerase IV (in plants): Involved in siRNA-mediated RNA-directed DNA methylation.

Step 3: Final Answer:
Therefore, tRNA is transcribed by RNA Polymerase III.