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.

Most suitable method of introducing alien $DNA$ into a plant cell is

The "molecular scissors" used in genetic engineering is

Which organism is most commonly used as a host in $r-DNA$ technology?

Identify the desirable characteristics for a plasmid used in $rDNA$ technology from the following.
$A$. Ability to multiply and express outside the host in a bioreactor.
$B$. $A$ highly active promoter
$C$. $A$ site at which replication can be initiated
$D$. One or more identifiable marker genes
$E$. One or more unique restriction sites.

Do eukaryotic cells have restriction endonucleases? Justify your answer.