If a person obtains transformants by inserting a recombinant DNA within the coding sequence of enzyme `beta-galatosidase, he will separate out recombinants from non-recombinats by which of the following observations ?

Options

A. 1) Non-recombinant colonies do not produce any colour whereas reccombinants give blue coloured colonies
B. 2) Recombinant colonies do not produce any colour whereas non-recombinants given blue coloured colonies.
C. 3)Recombinants and non-recombinants both produce blue coloured colonies
D. 4) No colonies are formed due to insertional inactivation

Answer

To solve the question regarding how to separate transformants with recombinant DNA from non-recombinants using the enzyme beta-galactosidase, we can follow these steps:

### Step-by-Step Solution:

1. **Understanding the Role of Beta-Galactosidase**:
- Beta-galactosidase is an enzyme that hydrolyzes lactose into glucose and galactose. In molecular biology, it is often used as a reporter gene.
- When beta-galactosidase is present in a system, it can convert a substrate called X-gal into a blue-colored product.

2. **Insertion of Recombinant DNA**:
- When recombinant DNA is inserted into the coding sequence of the beta-galactosidase gene, it can disrupt the normal function of the enzyme.
- This process is known as insertional inactivation, where the insertion of foreign DNA prevents the enzyme from being produced or functioning properly.

3. **Observing Colony Color**:
- In a blue-white screening method, colonies that contain the non-recombinant (intact) beta-galactosidase gene will produce the blue color when grown on a medium containing X-gal.
- Conversely, colonies that contain the recombinant DNA (where the beta-galactosidase gene is disrupted) will not produce the blue color and will appear white or colorless.

4. **Conclusion**:
- By observing the color of the colonies, one can distinguish between recombinants and non-recombinants:
- **Non-recombinant colonies**: Produce blue color (intact beta-galactosidase).
- **Recombinant colonies**: Do not produce color (disrupted beta-galactosidase).

### Final Answer:
The correct observation to separate recombinants from non-recombinants is:
- **Recombinant colonies do not produce any color whereas non-recombinants give blue colored colonies.** (This corresponds to option 2).

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