Which of the following is not synthesized by RNA polymerase III ?

Options

A. tRNA
B. snRNA
C. 5S rRNA
D. 5.8S rRNA

Answer

To determine which RNA is not synthesized by RNA polymerase III, we need to understand the functions of the different RNA polymerases in eukaryotic cells.

### Step-by-Step Solution:

1. **Identify the RNA Polymerases**: In eukaryotes, there are three main types of RNA polymerases:
- **RNA Polymerase I**: Synthesizes ribosomal RNA (rRNA) except for 5S rRNA.
- **RNA Polymerase II**: Synthesizes messenger RNA (mRNA) and some small nuclear RNAs (snRNA).
- **RNA Polymerase III**: Synthesizes transfer RNA (tRNA), 5S rRNA, and small nuclear RNAs (snRNA).

2. **List the Options**: The options given in the question are:
- tRNA
- SnRNA
- 5S rRNA
- 5.8S rRNA

3. **Analyze Each Option**:
- **tRNA**: Synthesized by RNA Polymerase III.
- **SnRNA**: Synthesized by RNA Polymerase III.
- **5S rRNA**: Synthesized by RNA Polymerase III.
- **5.8S rRNA**: This is synthesized by RNA Polymerase I, not RNA Polymerase III.

4. **Conclusion**: Since 5.8S rRNA is not synthesized by RNA Polymerase III, the correct answer is **5.8S rRNA**.

### Final Answer:
The RNA that is not synthesized by RNA polymerase III is **5.8S rRNA**.

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