If you can ligate foreign DNA at the BamHI site in the vector pBR322, which of the following will occur?

Options

A. The recombinant plasmid will lose the ability to confer ampicillin resistance to the host bacteria
B. Bacteria containing recombinant pBR322 are unable to grow in tetracycline containing medium
C. Bacteria with recombinant plasmid will lose resistance to both tetracycline and ampicillin
D. Recombinant bacteria grow in tetracycline containing medium but are unable to grow in ampicillin rich medium

Answer

To solve the question regarding the ligation of foreign DNA at the BamHI site in the vector pBR322, we need to analyze the implications of this action on the antibiotic resistance properties of the plasmid. Here’s a step-by-step breakdown of the solution:

### Step-by-Step Solution:

1. **Understand the Structure of pBR322**:
- pBR322 is a plasmid vector that contains genes for antibiotic resistance, specifically for ampicillin (AMP) and tetracycline (TET).
- The BamHI restriction site is located within the tetracycline resistance gene.

**Hint**: Familiarize yourself with the basic structure and function of plasmids, particularly pBR322.

2. **Identify the Role of BamHI**:
- BamHI is a restriction enzyme that cuts DNA at specific sequences. When foreign DNA is ligated at the BamHI site, it disrupts the tetracycline resistance gene.

**Hint**: Remember that ligation at a restriction site can disrupt the function of the gene located at that site.

3. **Analyze the Effects of Ligation**:
- Since the BamHI site is within the tetracycline resistance gene, ligation of foreign DNA will render this gene non-functional. This means that the bacteria containing the recombinant plasmid will lose the ability to grow in a medium containing tetracycline.

**Hint**: Consider what happens when a gene is disrupted—its function is typically lost.

4. **Evaluate the Impact on Ampicillin Resistance**:
- The BamHI site does not affect the ampicillin resistance gene, which remains intact. Therefore, the bacteria will still be able to grow in ampicillin-containing medium.

**Hint**: Distinguish between the effects on different antibiotic resistance genes when one is disrupted.

5. **Conclusion**:
- The correct outcome of ligating foreign DNA at the BamHI site in pBR322 is that the bacteria will be unable to grow in tetracycline-containing medium but will still be resistant to ampicillin.

**Hint**: Summarize the effects of the ligation on both antibiotic resistances to clarify the final answer.

### Final Answer:
- The correct statement is: **Bacteria containing recombinant pBR322 will be unable to grow in tetracycline-containing medium**.