Which of the following is not a characteristic of pBR322 vector ?

Options

A. 1) It was the first artificial cloning vector constructed in 1977 by
Boli-
ver
and Rodriguez.
B. 2) It is the most widely used,versatile and easily manipulated vector.
C. 3) It has two antibiotic resistance genes `tet^(R)` and `amp^(R)`
D. 4) It does not have restriction site for sall.

Answer

To determine which of the following statements is not a characteristic of the pBR322 vector, we will analyze each statement one by one.

1. **Statement 1**: "It was the first artificial cloning vector constructed in 1977 by Bolivar and Rodriguez."
- This statement is true. pBR322 was indeed the first artificial cloning vector created in 1977 by researchers Bolivar and Rodriguez. The name pBR322 reflects this.

2. **Statement 2**: "It is the most widely used, versatile and easily manipulated vector."
- This statement is also true. pBR322 is known for its versatility and ease of manipulation, making it one of the most widely used vectors in molecular biology.

3. **Statement 3**: "It has two antibiotic resistance genes, tetracycline resistance and ampicillin resistance."
- This statement is correct as well. pBR322 contains two antibiotic resistance genes: one for tetracycline and another for ampicillin. These genes serve as selectable markers to identify successfully transformed cells.

4. **Statement 4**: "It does not have a restriction site for Sal-1."
- This statement is false. pBR322 does have a restriction site for the enzyme Sal-1, located within the region that confers tetracycline resistance. Therefore, this statement does not accurately describe pBR322.

Based on the analysis above, the statement that is not a characteristic of pBR322 is:

**Answer**: 4. It does not have a restriction site for Sal-1.

---