Restriction enzymes are:

In plasmid $DNA$,the regulation of the process of replication,other than the origin of replication,is controlled by:

$EcoRI$ cleaves the $DNA$ strands to produce

$A$ : $Pst I$ generates single-stranded overhanging stretches in $DNA$ after digestion that facilitate ligation.
$R$ : These short extensions can form hydrogen bonds with their complementary counterparts,which are then sealed by $DNA$ ligase to form phosphodiester bonds.

Which restriction enzyme produces blunt ends upon cleavage?

In genetic engineering,the modification of $DNA$ has become possible due to the discovery of .............. .