Which vector can clone small pieces of $DNA$?

Define the following terms: Sticky ends and Transgene.

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:

Which of the following is used in recombinant $DNA$ technology?

The enzymes which are absolutely necessary for recombinant $DNA$ technology are

Which enzyme is responsible for cutting $DNA$ segments?