In lac operon, promoter gene provides the binding site for

Options

A. `beta` - galactosidase
B. Lactose
C. Repressor protein
D. RNA polymerase

Answer

To solve the question regarding the binding site provided by the promoter gene in the lac operon, we can follow these steps:

### Step-by-Step Solution:

1. **Understanding the Components of the Lac Operon**:
- The lac operon consists of several key components: the promoter, operator, and structural genes (Z, Y, A).
- The promoter is a specific DNA sequence where RNA polymerase binds to initiate transcription.

2. **Identifying the Role of the Promoter**:
- The promoter serves as the binding site for RNA polymerase, which is the enzyme responsible for synthesizing RNA from the DNA template.
- It does not bind to beta-galactosidase, lactose, or the repressor protein.

3. **Understanding the Function of the Repressor Protein**:
- The lac repressor protein binds to the operator region, not the promoter. When it binds to the operator, it prevents RNA polymerase from transcribing the genes in the operon.

4. **Conclusion**:
- Since the question asks for the binding site provided by the promoter gene, the correct answer is that the promoter gene provides the binding site for RNA polymerase.

### Final Answer:
The promoter gene in the lac operon provides the binding site for **RNA polymerase**.

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