Which process takes place in a bioreactor?

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.

Which of the following represents an advantage of growing cells in continuous culture as compared to a shake flask?

Select the correct statements from the following:

Following enzymes/chemical/technique are used in the process of gel electrophoresis:
$I.$ sample $DNA$ is cut into fragments
$II.$ restriction endonucleases
$III.$ agarose gel
$IV.$ ethidium bromide
$V.$ $UV$-radiation
$VI.$ elution
Mark the correct sequence of their use.

Select the incorrect statement regarding the continuous culture system.