Which of the statement is true for pBR322?
A. It contains only an ampicillin resistance gene
B. It contains both ampicillin resistant and tetracycline-resistant gene
C. The cloning site is present only in the ampicillin-resistant gene
D. It is a natural vector
Explanation: pBR 322 is the man-made vector. It contains both ampicillin-resistant and tetracycline-resistant genes. The cloning site is also present in both of the genes.