Biology · PYQ NEET UG 2021

Plasmid pBR322 has Pst I restriction enzyme site within gene \( amp^R \) that confers ampicillin resistance. If this enzyme is used for inserting a gene for \( \beta \)-galactoside production and the recombinant plasmid is inserted in an E.coli strain

it will be able to produce a novel protein with dual ability.
it will not be able to confer ampicillin resistance to the host cell.
the transformed cells will have the ability to resist ampicillin as well as produce \( \beta \)-galactoside.
it will lead to lysis of host cell.

Correct answer · Option 2

it will not be able to confer ampicillin resistance to the host cell.

Insertion inactivation of \( amp^R \) by Pst I causes loss of ampicillin resistance, so transformed cells cannot confer ampicillin resistance.