$A$ : Pst I generates single stranded over hanging stretches in $DNA$ after digestion that facilitate ligation.

$R$ : These short extensions can form phosphodiester bonds with their complementary counterparts.

The sequence that controls the copy number of the linked $DNA$ in the vector, is termed 

Upon exposure to UV radiation, DNA stained with ethidium bromide will show

Plasmid $pBR322$ has $PstI$ restriction enzyme site within gene $a m p^{R}$ 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

The "Ti plasmid" of Agrobacterium tumefaciens stands for