What is the first step in the Southern blot technique?

Which of the statements are correct about bioreactors?
$I.$ It provides all the optimal conditions for achieving the desired product by providing optimal growth conditions like temperature, $pH$, substrate, salt, vitamin and oxygen.
$II.$ It is suited for large-scale production of microorganisms under aseptic conditions for a number of days.

The flowchart given below represents the process of recombinant $DNA$ technology. Identify $A$,$B$,and $C$.

In this technique,large quantities of biotechnological products such as antibiotics,vaccines,and enzymes are produced by maintaining and growing only the desired microbes/eukaryotic cells in a sterile environment.

In a chemical process,the $DNA$ fragments produced by restriction endonucleases can be separated by:

The cutting of $DNA$ by restriction endonucleases results in the fragments of $DNA$. These fragments can be separated by a technique known as ......