The $rop$ gene,which codes for the proteins involved in the replication of the plasmid $pBR322$ in $E. coli$,is located at the restriction site of:

Choose the correct option based on the copy number capacity in a bacterial cell.

While isolating $DNA$ from bacteria,which of the following enzymes is not used?

Select the option that excludes characteristics applicable to plasmids:
$(a)$. Circular $DNA$
$(b)$. Linear $DNA$
$(c)$. Present in all bacteria
$(d)$. Contain essential genes
$(e)$. Extra chromosomal self-replicating

Restriction enzymes are isolated chiefly from:

The given figure is the diagrammatic representation of the $E. coli$ vector $pBR322$. Which one of the given options correctly identifies its certain component$(s)$?