In the Lac operon system, Beta-galactosidase is coded by

Options

A. a-gene
B. i-gene
C. L-gene
D. zgene

Answer

To solve the question regarding which gene codes for beta-galactosidase in the Lac operon system, we can follow these steps:

### Step-by-Step Solution:

1. **Understand the Operon Concept**:
- An operon is a cluster of genes under a single promoter that are transcribed together. In this case, we are looking at the Lac operon, which is involved in the metabolism of lactose in E. coli.

2. **Identify the Genes in the Lac Operon**:
- The Lac operon consists of three structural genes:
- **Z gene**: Codes for beta-galactosidase.
- **Y gene**: Codes for permease.
- **A gene**: Codes for transacetylase.

3. **Focus on Beta-galactosidase**:
- Since the question specifically asks about beta-galactosidase, we need to determine which of the genes codes for this enzyme.

4. **Match the Gene with the Enzyme**:
- From our identification, we see that the Z gene is responsible for coding beta-galactosidase.

5. **Conclusion**:
- Therefore, the answer to the question is that beta-galactosidase is coded by the **Z gene**.

### Final Answer:
Beta-galactosidase is coded by the **Z gene** in the Lac operon system.

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