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

Genetic engineering is possible because:

$A$ - Restriction endonucleases are also called 'molecular scissors'.
$R$ - When fragments generated by restriction endonucleases are mixed,they join together due to their sticky ends.

The plasmid used for the construction of the first artificial recombinant $DNA$ molecule was obtained from which microorganism?

In the gene gun method used to introduce alien $DNA$ into host cells,microparticles of which metal are used?

Which of the following statements is true regarding plasmids?