Which one of the following causes crown gall disease?

There is a restriction endonuclease called $Eco RI$. What does "co" part in it stand for?

Explain the 'cloning sites' in cloning vectors.

In the naming of restriction enzymes, the first letter is derived from $...A...$ name, the next two letters from the $...B...$, and the fourth letter from $...C...$ of $...D...$ where the enzymes are extracted.
$A$ to $D$ in the statement can be:

Recombinant $DNA$ is achieved by cleaving the pro-$DNA$ by

The ligation of an antibiotic resistance gene with a plasmid vector can be performed by which of the following enzymes?