After completing the transformation experiment involving the coding sequence of enzyme n -galactosidase, the recombinant colonies should:

Options

A. Give blue colour
B. Not give blue colour
C. Have active β-galactosidase
D. Both (2) and (3)

Answer

To solve the question regarding the outcome of a transformation experiment involving the coding sequence of the enzyme β-galactosidase, we can follow these steps:

### Step-by-Step Solution:

1. **Understanding the Role of β-galactosidase**:
- β-galactosidase is an enzyme that breaks down lactose into glucose and galactose. In the context of molecular biology, it is often used as a reporter gene.

2. **Transformation Process**:
- During the transformation experiment, a plasmid (vector) containing the β-galactosidase gene is introduced into bacterial cells. If the plasmid remains intact (without foreign DNA), the β-galactosidase gene is expressed.

3. **Effect of Inserting Foreign DNA**:
- If foreign DNA is inserted into the plasmid at the site of the β-galactosidase gene, this disrupts the gene's coding sequence. As a result, the β-galactosidase enzyme is not produced.

4. **Chromogenic Substrate Interaction**:
- In the presence of an active β-galactosidase enzyme, a chromogenic substrate (such as X-gal) is converted into a blue-colored product, resulting in blue colonies.
- Conversely, if the β-galactosidase gene is inactive (due to the insertion of foreign DNA), the enzyme is not produced, and the chromogenic substrate remains unprocessed, leading to white colonies.

5. **Conclusion**:
- After completing the transformation experiment, the recombinant colonies that contain the inserted foreign DNA will not produce β-galactosidase. Therefore, they will not exhibit the blue color associated with active β-galactosidase. Instead, they will appear white.

### Final Answer:
The recombinant colonies should **not give blue color** and will be **white** due to the inactivity of the β-galactosidase gene after the insertion of foreign DNA.

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