NEETZoologyBiotechnology - Principles and Processes
A foreign DNA is ligated at the BamHI site of the cloning vector pBR322. The resulting recombinant plasmid is introduced into an E. coli host. Which of the following correctly describes the antibiotic resistance profile of the recombinant transformants?
Options
- AThey will be resistant to both ampicillin and tetracycline.
- BThey will be sensitive to both ampicillin and tetracycline.
- CThey will be resistant to tetracycline but sensitive to ampicillin.
- DThey will be resistant to ampicillin but sensitive to tetracycline.
Correct answer
D. They will be resistant to ampicillin but sensitive to tetracycline.
Step-by-step solution
In the cloning vector pBR322, the recognition site for the restriction endonuclease BamHI is located within the tetracycline resistance gene ( tet^ R ). When a foreign DNA is inserted at this site, it leads to the insertional inactivation of the tet^ R gene. As a result, the recombinant plasmid loses its ability to confer resistance to tetracycline. However, the ampicillin resistance gene ( amp^ R ) remains intact. Therefore, the recombinant transformants will be resistant to ampicillin but sensitive to tetracyclin