Which of the following enzymes hydrolyzes the internal phosphodiester bonds in a polynucleotide chain?

The two antibiotic resistance genes on vector $pBR322$ are for

The most thoroughly studied of the known bacteria-plant interactions is the

Which of the following foreign $DNA$ cannot multiply within a host cell?

Restriction enzymes that are used in the construction of recombinant $DNA$ are endonucleases which cut the $DNA$ at 'specific-recognition sequence'. What would be the disadvantage if they do not cut the $DNA$ at specific-recognition sequence?

$A$ plasmid: