$DNA$ carries a ..... charge,so it moves towards the ......... electrode.

An extrachromosomal $DNA$,which can be used as a vector in gene cloning is called:

Endonuclease . . . . . . .

Which of the following is not used for isolation of $\text{DNA}$ from cells?

$A$: Restriction enzymes belong to a larger class of enzymes called nucleases.
$R$: Each restriction enzyme recognizes a specific palindromic nucleotide sequence in the $DNA$.

The plasmid used for the construction of the first artificial recombinant $DNA$ molecule was obtained from which microorganism?