mRNA is eukaryotes is synthesized on `3'to5'` strand of DNA in `5'to3'` direction with the help of

Options

A. RNA polymerase I (Pol I)
B. Pol (II)
C. Pol III
D. DNA polymerase

Explanation

To solve the question regarding which enzyme is responsible for the synthesis of mRNA in eukaryotes, we can follow these steps:

### Step-by-Step Solution:

1. **Understand the Question**: The question states that mRNA is synthesized on the `3' to 5'` strand of DNA in the `5' to 3'` direction. This indicates that we are looking for the enzyme that facilitates this process.

2. **Identify the Enzymes**: The options provided are:
- RNA polymerase I
- RNA polymerase II
- RNA polymerase III
- DNA polymerase

3. **Analyze RNA Polymerase I**:
- RNA polymerase I is primarily responsible for synthesizing rRNA (ribosomal RNA), specifically the 45S precursor rRNA.
- Therefore, it does not play a role in mRNA synthesis.

4. **Analyze RNA Polymerase II**:
- RNA polymerase II is crucial for the synthesis of mRNA. It synthesizes precursor mRNA and is also involved in the formation of small nuclear RNAs (snRNA) and micro RNAs (miRNA).
- This enzyme synthesizes mRNA in the `5' to 3'` direction using the `3' to 5'` strand of DNA as a template.

5. **Analyze RNA Polymerase III**:
- RNA polymerase III is responsible for synthesizing tRNA (transfer RNA) and 5S rRNA.
- It does not synthesize mRNA.

6. **Analyze DNA Polymerase**:
- DNA polymerase is involved in DNA replication, not transcription. It does not play a role in synthesizing mRNA.

7. **Conclusion**: Based on the analysis, the only enzyme responsible for the synthesis of mRNA in eukaryotes is RNA polymerase II.

### Final Answer:
The correct answer is **RNA polymerase II**.

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