The most commonly used enzyme for polymerase chain reaction is

The function of nucleases is to ........

The enzymes which are absolutely necessary for recombinant $DNA$ technology are

$I.$ Bacteriophages are $...A...$ infecting $...B....$
$II. ...C...$ are hybrid vectors derived from plasmids which contain $cos$ site of $\lambda$ phage.
$A, B$ and $C$ in above statements refer to:

In gel electrophoresis, the separated $DNA$ fragments can be visualized only after staining the $DNA$ with a compound known as ............. followed by exposure to $UV$ radiation.

The introduction of $T-DNA$ into plants involves