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

Identify the regions marked as $A$,$B$,and $C$ in the given diagram of the cloning vector $pBR322$.

Where is $BamHI$ located in $pBR322$?

Ligases catalyse the formation of bonds between

How many recognition sites are present for each restriction enzyme in the cloning vector $pBR322$?

$A$ plasmid $DNA$ and a linear $DNA$ (both are of the same size) have one site for a restriction endonuclease. When cut and separated on agarose gel electrophoresis,the plasmid shows one $DNA$ band while the linear $DNA$ shows two fragments. Explain.