$A$ - Cloning vectors are useful to transfer desirable $DNA$ into host cells.
$R$ - Agrobacterium tumefaciens is a pathogen of several dicot plants.

........ make cuts at specific positions within the $DNA$.

$I.$ $Ori$ also controls the copy number of the linked $DNA$.
$II.$ If a foreign $DNA$ ligates at the $BamHI$ site of the tetracycline resistance gene in the vector $pBR322$,the recombinant plasmid loses the tetracycline resistance due to the insertion of foreign $DNA$.
Choose the correct option regarding the above statements.

$Taq$ polymerase is isolated from a

Restriction endonucleases are enzymes which

Which of the following is the first restriction endonuclease discovered?