In a experiment , in pBR322 an alien DNA is introduced using sal I. The transformant will grow on

Options

A. Tetracycline
B. Ampicillin
C. Both (A) and (B)
D. None of these

Answer

To solve the question regarding the growth of transformants after introducing alien DNA into the plasmid pBR322 using the restriction enzyme Sal I, we can follow these steps:

### Step-by-Step Solution:

1. **Understanding pBR322**:
- pBR322 is a plasmid vector that contains antibiotic resistance genes, specifically for ampicillin and tetracycline. These genes allow for the selection of transformants that have successfully taken up the plasmid.

2. **Introduction of Alien DNA**:
- When alien DNA is introduced into pBR322 using the restriction enzyme Sal I, it is inserted into a specific site within the plasmid. In this case, the alien DNA is likely inserted into the tetracycline resistance gene region.

3. **Effect of Insertion on Resistance**:
- The insertion of the alien DNA disrupts the tetracycline resistance gene. As a result, the transformed plasmid will no longer confer resistance to tetracycline. However, the ampicillin resistance gene remains intact.

4. **Selection of Transformants**:
- When the transformed bacteria are cultured on media containing antibiotics, only those that have taken up the plasmid (transformants) will survive. Since the tetracycline resistance has been disrupted, transformants will not survive on tetracycline-containing media.

5. **Conclusion**:
- The transformants will be able to grow on media containing ampicillin because they still possess the ampicillin resistance gene. Therefore, the correct answer is that the transformants will grow on ampicillin.

### Final Answer:
The transformant will grow on **ampicillin**.

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