In which type of bioreactor do air bubbles increase the oxygen transfer area?

What happens if a foreign $DNA$ fragment is inserted into the coding sequence of the $\beta$-galactosidase enzyme in a plasmid containing the coding sequence for the $\beta$-galactosidase enzyme?

Polymerase chain reaction is most useful in

Which of the following techniques is $NOT$ used for introducing $DNA$ into a host cell in $r-DNA$ technology?

To introduce recombinant $DNA$ into a host cell,it is first kept on ice,then placed at ........ temperature,and finally placed back on ice. (in $^{\circ} C$)

Bioreactors are useful in