Suppose the gene of interest is inserted as Pstl site in pBR322, the resulting plasmid will confer resistance to :

Options

A. Ampicillin
B. Penicillin
C. Ampicillin and tetracycline
D. Tetracycline

Answer

To solve the question regarding the plasmid pBR322 and the insertion of a gene of interest at the PstI site, we can follow these steps:

### Step-by-Step Solution:

1. **Understand the Structure of pBR322**:
- pBR322 is a plasmid that contains two important antibiotic resistance genes: one for ampicillin and one for tetracycline.

2. **Identify the PstI Site**:
- The PstI site is a specific location on the plasmid where the gene of interest can be inserted. In this case, it is important to know which resistance gene is affected by this insertion.

3. **Insertion of Gene of Interest**:
- When the gene of interest is inserted at the PstI site, it disrupts the sequence of the gene that confers resistance to ampicillin. This means that the recombinant plasmid will no longer be able to confer resistance to ampicillin.

4. **Determine the Resulting Resistance**:
- Since the ampicillin resistance gene is disrupted, the only remaining functional resistance that the plasmid can confer is to tetracycline. Therefore, the recombinant plasmid will exhibit resistance to tetracycline.

5. **Eliminate Incorrect Options**:
- The options provided include ampicillin, penicillin, ampicillin and tetracycline, and tetracycline. Since the ampicillin resistance is disrupted, we can eliminate options that include ampicillin. Penicillin is not relevant in this context, so it can also be eliminated.

6. **Select the Correct Answer**:
- The only option left is tetracycline, which is the correct answer.

### Final Answer:
The resulting plasmid will confer resistance to **tetracycline**.

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