Which antibiotic resistance genes will you find in the modified vector pBR322?
A. Ampicillin
B.Erythromycin
C. Tetracycline
D. Both ( A) and (C)

Options

A. A. Ampicillin
B. B. Erthromycin
C. C. Tetracycline
D. D. Both ( 1) and (3)

Answer

To answer the question, "Which antibiotic resistance genes will you find in the modified vector pBR322?" we will analyze the options provided and the characteristics of the pBR322 vector.

### Step-by-Step Solution:

1. **Understand the pBR322 Vector**:
- pBR322 is a plasmid vector commonly used in genetic engineering.
- It is approximately 4.4 kb in size and contains an origin of replication (ori) and multiple restriction sites.

2. **Identify Selectable Markers**:
- pBR322 has two main selectable markers for antibiotic resistance:
- **Ampicillin resistance gene** (often denoted as **bla**)
- **Tetracycline resistance gene** (often denoted as **tet**)

3. **Evaluate the Options**:
- **Option A: Ampicillin** - This is correct as pBR322 contains an ampicillin resistance gene.
- **Option B: Erythromycin** - This is incorrect as pBR322 does not contain an erythromycin resistance gene.
- **Option C: Tetracycline** - This is correct as pBR322 contains a tetracycline resistance gene.
- **Option D: Both A and C** - This option is correct because both ampicillin and tetracycline resistance genes are present in pBR322.

4. **Conclusion**:
- The correct answer is **Option D: Both A and C**.