Which restriction site is present in the $amp^R$ gene in $pBR322$?

The two bacteria found to be very useful in genetic engineering experiments are .............. .

Which statement is correct for the $tet^R$ gene in the $pBR322$ plasmid?

$I.$ 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:

What is the function of the enzyme known as molecular scissors?

Cutting of a piece of $DNA$ from a plasmid was done with the help of $...A...$ enzymes,popularly known as $...B....$ Here $A$ and $B$ can be