The term "Molecular Scissors" refers to

$I.$ Bacteriophages are $...A...$ infecting $...B....$
$II. ...C...$ are hybrid vectors derived from plasmids which contain $cos$ site of $\lambda$ phage.
$A, B$ and $C$ in above statements refer to:

What type of biological molecules are cloning vectors?

Which of the following is an $E. coli$ cloning vector?

Due to the chloramphenicol resistance gene,one is able to select a transformed cell in the presence of chloramphenicol. The chloramphenicol resistance gene in this case is called:

$A$ - $amp^R$ has recognition sites for $Pvu I$.
$R$ - $tet^R$ gene has no recognition site for $Hind III$.