Identify the following bioreactors.
$P \quad\quad Q$

For selection of recombinants,insertional inactivation of antibiotic marker has been superceded by insertional inactivation of a marker gene coding for a chromogenic substrate. Give reasons.

When a protein-encoding gene is expressed in a heterologous host, it is called a:

Which technique is used to check the progression of a restriction enzyme digestion?

Which of the following steps are involved in the process of recombinant biotechnology? Arrange in correct order.
$I.$ Extraction of the desired gene product
$II.$ Amplification of the gene of interest
$III.$ Isolation of a desired $DNA$ fragment
$IV.$ Ligation of the $DNA$ fragment into a vector
$V.$ Insertion of recombinant $DNA$ into the host
Correct order is:

What is the first step in the Southern blot technique?