Section 3: Genetics, Cellular and Molecular Biology
DNA replication, transcription, translation
Subtopic: Fundamentals of DNA replication, transcription, translation
Question Statement:
Eukaryotic transcription is carried out by
Options:
(A) DNA-dependent RNA polymerase
(B) DNA-dependent DNA polymerase
(C) RNA-dependent DNA polymerase
(D) RNA-dependent RNA polymerase
Official Answer Key:
A
Step-by-Step Solution & Explanation
### **Official Solution & Concept Analysis (GATE BT 2023 Q.11)**
**1. Governing Concept**:
- **Topic**: Molecular Biology & Eukaryotic Transcription
- Eukaryotic transcription synthesizes RNA using a double-stranded genomic DNA template. The core enzymes catalyzing this process are eukaryotic **DNA-dependent RNA polymerases** (RNA Pol I, Pol II, and Pol III).
**2. Option Analysis**:
- **Option (A) [DNA-dependent RNA polymerase] is CORRECT**: Accurately describes the enzyme class transcribing DNA into RNA.
- **Option (B) [DNA-dependent DNA polymerase] is INCORRECT**: DNA replicases (Pol $\alpha, \delta, \epsilon$) replicating genomic DNA.
- **Option (C) [RNA-dependent DNA polymerase] is INCORRECT**: Reverse transcriptase synthesizes DNA from RNA.
- **Option (D) [RNA-dependent RNA polymerase] is INCORRECT**: Viral replicase synthesizing RNA from viral RNA genomes.
**3. Final Answer**:
- **Correct Choice**: **A**
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