Small nuclear RNA is transcribed by

Options

A. RNA Polymerase I
B. RNA Polymerase III
C. RNA Polymerase II
D. Both (1) and (3)

Answer

To solve the question "Small nuclear RNA is transcribed by," we can follow these steps:

### Step-by-Step Solution:

1. **Understand the Types of RNA Polymerases in Eukaryotes**:
- In eukaryotic cells, there are three main types of RNA polymerases: RNA polymerase I, RNA polymerase II, and RNA polymerase III.

2. **Identify the Function of Each RNA Polymerase**:
- **RNA Polymerase I**: This enzyme is responsible for transcribing ribosomal RNA (rRNA), specifically the 28S, 18S, and 5.8S rRNA.
- **RNA Polymerase II**: This enzyme transcribes messenger RNA (mRNA), which is the precursor of mRNA and is often referred to as heterogeneous nuclear RNA (hnRNA).
- **RNA Polymerase III**: This enzyme is responsible for transcribing small RNAs, including transfer RNA (tRNA), 5S rRNA, and small nuclear RNA (snRNA).

3. **Focus on Small Nuclear RNA**:
- The question specifically asks about small nuclear RNA (snRNA). According to the functions of the RNA polymerases, small nuclear RNA is transcribed by RNA polymerase III.

4. **Select the Correct Answer**:
- Since small nuclear RNA is transcribed by RNA polymerase III, the correct answer to the question is option number 2, which corresponds to RNA polymerase III.

### Final Answer:
Small nuclear RNA is transcribed by RNA polymerase III.

---