NEET2026ZoologyBiotechnology - Principles and ProcessesActual
Insertion of a foreign DNA at BamHI site in an E. coli cloning vector pBR322 results in the loss of antibiotic resistance towards :
Options
- AAmpicillin and tetracycline
- BAmpicillin
- CTetracycline
- DGentamycin
Correct answer
C. Tetracycline
Step-by-step solution
The cloning vector pBR322 contains two antibiotic resistance genes: ampicillin resistance ( amp^ R ) and tetracycline resistance ( tet^ R ). The restriction site for the enzyme BamHI is located within the tetracycline resistance gene ( tet^ R ). When a foreign DNA is inserted at the BamHI site, the tet^ R gene gets interrupted. This phenomenon is known as insertional inactivation. Due to this insertional inactivation, the recombinant plasmid loses its ability to confer resistance against tetracycline, while the amp