Select the incorrect statement.

Options

A. Insertional inactivation technique helps in identification of the recombinant transformants with non - transformants by forming colourless colonies.
B. Insertional inactivation of `beta` - galactosidase leads to the formation of colourless colonies.
C. Insertional inactivation of `beta` - galactosidase leads to the formation of blue colour colonies.
D. In insertional inactivation , the rDNA is inserted within the coding sequence of an enzyme `beta` galactosidase.

Answer

To solve the question of identifying the incorrect statement regarding the insertional inactivation technique, we will analyze each statement provided in the question step by step.

### Step-by-Step Solution:

1. **Understanding Insertional Inactivation**:
- Insertional inactivation is a technique used to identify recombinant DNA (rDNA) transformants by inserting foreign DNA into a specific gene, disrupting its function.

2. **Role of Beta-Galactosidase**:
- Beta-galactosidase is an enzyme that breaks down lactose into glucose and galactose. When the gene coding for this enzyme is disrupted by the insertion of foreign DNA, the enzyme is not produced.

3. **Color Indicators**:
- Transformants (cells that have taken up the foreign DNA) will not produce beta-galactosidase, resulting in colorless colonies when grown on a chromogenic substrate.
- Non-transformants (cells that have not taken up the foreign DNA) will produce beta-galactosidase, leading to blue-colored colonies.

4. **Analyzing the Statements**:
- **Statement 1**: "Insertion and inactivation technique helps in identification of recombinant transformants from non-recombinants by forming colorless colonies."
- This statement is **correct**. It accurately describes the identification process.

- **Statement 2**: "The insertion and inactivation of beta-galactosidase leads to formation of colorless colonies."
- This statement is also **correct**. The inactivation of beta-galactosidase results in colorless colonies.

- **Statement 3**: "Insertion inactivation of beta-galactosidase leads to blue colored colony."
- This statement is **incorrect**. Insertional inactivation does not lead to blue colonies; it leads to colorless colonies.

- **Statement 4**: "The insertional inactivation that rDNA is inserted within the coding sequence of enzyme beta-galactosidase."
- This statement is **correct**. It correctly states that the rDNA is inserted into the coding sequence of beta-galactosidase.

5. **Conclusion**:
- The incorrect statement is **Statement 3**. Therefore, the answer to the question is that the incorrect statement is the one that claims insertion inactivation leads to blue colored colonies.

### Final Answer:
The incorrect statement is: **"Insertion inactivation of beta-galactosidase leads to blue colored colony."**