Question

Eukaryotic transcription is carried out by

• A. DNA-dependent RNA polymerase
• B. DNA-dependent DNA polymerase
• C. RNA-dependent DNA polymerase
• D. RNA-dependent RNA polymerase

Hint:

- Remember: transcription = DNA → RNA, carried out by DNA-dependent RNA polymerase.
- Replication = DNA → DNA, carried out by DNA-dependent DNA polymerase.
- Reverse transcription = RNA → DNA, by RNA-dependent DNA polymerase.
- Viral RNA replication = RNA → RNA, by RNA-dependent RNA polymerase.

Answer 1

The Correct Option is A

Step 1: Transcription is the process of synthesizing RNA from a DNA template.
Step 2: In eukaryotes, specific enzymes known as RNA polymerases are responsible for this process. These enzymes read the DNA template and synthesize a complementary RNA strand.
Step 3: The correct enzyme is therefore DNA-dependent RNA polymerase, because:
- It depends on DNA as a template.
- It produces RNA as the product.
Step 4: The other options are incorrect:
- (B) DNA-dependent DNA polymerase is for DNA replication, not transcription.
- (C) RNA-dependent DNA polymerase (reverse transcriptase) is used by retroviruses.
- (D) RNA-dependent RNA polymerase is used by RNA viruses for RNA replication.
Final Answer: Eukaryotic transcription is carried out by DNA-dependent RNA polymerase.
\[\boxed{\text{Correct Answer: (A)}}\]