Zoology - Biotechnology - Principles and Processes Question with Solution | TestHub

Option (2) is the answer because, In pBR322, the restriction site for $Bam\mathrm{HI}$ is present in tet ${}^{\mathrm{R}}$ gene. Therefore, ligation of a foreign DNA will results in loss of tetracycline resistance and recombinants will be tetracycline sensitive. Option (1) is not the answer because, In pBR322, the restriction site of EcoR I is present outside the region of $am{p}^R$ gene and tet ${}^R$ gene. Option (3) and (4) are not the answers because, in pBR322, the restriction sites for $PstI$ and $PvuI$ are present in ${\mathrm{amp}}^{\mathrm{R}}$ gene. So, ligation of foreign DNA will result in loss of ampicillin resistance and recombinants will be ampicillin sensitive.