In which method is recombinant $DNA$ directly injected into the nucleus of an animal cell?

In the presence of a chromogenic substrate,what color colonies do recombinants and non-recombinants produce,respectively?

What is the first step in the Southern blot technique?

$I.$ $DNA$ being a hydrophilic molecule cannot pass through cell membranes.
$II.$ The bacteria should be made competent to accept the $DNA$ molecule.
The correct option regarding the above statements is:

Explain the method for the separation and isolation of $DNA$ fragments.

The preparatory phase before fermentation is known as: