Bioreactors are useful in

Which of the following is not a step of downstream processing?

An artificial process of infecting cells with naked viral $DNA$ is:

$DNA$ precipitation out of a mixture of biomolecules can be achieved by treatment with

Study the given figure carefully and select the correct statements regarding this.
$I.$ It represents typical agarose gel electrophoresis showing differential migration of $DNA$ fragments.
$II.$ Lane $1$ contains undigested $DNA$ fragments.
$III.$ Lanes $2$ to $4$ contain digested $DNA$ fragments.
$IV.$ Smallest $DNA$ bands are present at $(A)$ position and largest $DNA$ bands are present at $(B)$ position.

How many steps are there in one $PCR$ cycle?