Which cellular component is associated with genetic engineering?

Which technique is used for the separation of $DNA$ fragments?

Which of the following is the first restriction endonuclease discovered?

$A$ plasmid is a ...

Two enzymes responsible for restricting the growth of bacteriophages in $E. coli$ were isolated. One was methylase and the other was restriction endonuclease. What is the significance of methylase?

From which organism is the $Taq$ polymerase enzyme isolated?