What is the process of cutting out the $DNA$ bands from the agarose gel and extracting them from the gel piece called?

The components of a bioreactor are:
$I.$ An agitator system
$II.$ An oxygen delivery system
$III.$ Foam control system
$IV.$ Temperature control system
$V.$ $pH$ control system
$VI.$ Sampling ports to withdraw cultures periodically
Choose the correct option.

Which of the following is not required for $PCR$?

What is the first step in the Southern blot technique?

The enzyme $(a)$ is needed for isolating genetic material from plant cells and enzyme $(b)$ for isolating genetic material from fungus. Choose the correct pair of options from the following:

The stirrer in a stirred-tank bioreactor facilitates: