The process of separation and purification of the expressed protein before marketing is called .........

Give scientific reasons: Hepatitis $B$ and Bird flu $DNA$ vaccines are called Recombinant $DNA$ vaccines.

Select the correct sequence of steps in $PCR$.

What is the first step in the Southern Blot technique?

In a bioreactor,through which system can a small volume of culture be withdrawn periodically?

Consider the following statements:
$I.$ In microinjection method,foreign $DNA$ is directly injected into the nucleus of an animal cell or plant cell by using microneedles or micropipettes.
$II.$ Microinjection method is used in oocytes,eggs,and embryos.
$III.$ Electroporation is the formation of temporary pores in the plasma membrane of a host cell by using lysozyme or calcium chloride.
$IV.$ In chemical-mediated gene transfer method,certain chemicals such as $CO_{2}$ help foreign $DNA$ to enter the host cell.
Which of the statements given above are correct?