In bacteria,genes for antibiotic resistance are usually located in:

In bacteria,a plasmid is .........

About gene gun method:
$I.$ This method is also known as biolistic technique.
$II.$ In this method,cells are bombarded with high-velocity micro-particles of gold or tungsten coated with $DNA$ in plants.
$III.$ Important crop plants like maize,rice,and wheat have now been transformed by this method.
Which of the statements given above are correct?

In recombinant $DNA$ technology,the term vector refers to a

Select the incorrect statement from the following.

Plasmids are ........