Question

Match List-I with List-II
List-I (Name of the enzyme in Eukaryotes) vs List-II (Type of RNA synthesized)
(A) RNA Pol I - (I) mRNA
(B) RNA Pol II - (II) tRNA
(C) RNA Pol III - (III) rRNA
Choose the correct answer from the options given below:

• (A) - (II), (B) - (III), (C) - (I)
• (A) - (I), (B) - (III), (C) - (II)
• (A) - (III), (B) - (II), (C) - (I)
• (A) - (III), (B) - (I), (C) - (II)

Hint:

Remember the numbering sequence (I, II, III) in the order of translation requirements:
- Pol I $\rightarrow$ rRNA (Ribosomal structure, first component needed).
- Pol II $\rightarrow$ mRNA (The template containing the genetic code).
- Pol III $\rightarrow$ tRNA (The adapter molecule bringing amino acids).

Answer 1

The Correct Option is D

Step 1: Understanding the Concept:
Unlike prokaryotes which utilize a single RNA polymerase for all transcription, eukaryotes possess three distinct nuclear RNA polymerases (I, II, and III), each responsible for synthesizing specific classes of RNA.
Detailed Explanation:
Let us match each eukaryotic RNA polymerase with its respective transcript class:
- (A) RNA Polymerase I: Located in the nucleolus, this enzyme is responsible for synthesizing the ribosomal RNA (rRNA) precursor ($45\text{S}$ in mammals), which is processed into the $28\text{S}$, $18\text{S}$, and $5.8\text{S}$ rRNAs.
This matches with (III).
- (B) RNA Polymerase II: Located in the nucleoplasm, this enzyme is responsible for synthesizing messenger RNAs (mRNAs, the precursors of proteins) as well as most small nuclear RNAs (snRNAs) and microRNAs (miRNAs).
This matches with (I).
- (C) RNA Polymerase III: Located in the nucleoplasm, this enzyme is responsible for synthesizing small, stable RNAs, primarily transfer RNAs (tRNAs), $5\text{S}$ ribosomal RNA, and U6 snRNA.
This matches with (II).
Combining these matches, we get: (A) - (III), (B) - (I), (C) - (II).

Step 2: Final Answer:
The correct matching sequence corresponds to option (D).