The $Polyethylene \text{ } Glycol$ $(PEG)$ method is used for:

Separated bands of $\text{DNA}$ in agarose gel electrophoresis observed under $\text{UV}$ radiation are stained with

Consider the following statements about $PCR$:
$I.$ Polymerase Chain Reaction $(PCR)$ is a technique of synthesizing multiple copies of the desired gene in vitro.
$II.$ This technique was developed by Kary Mullis in $1985$.
$III.$ $A$ single $PCR$ amplification cycle involves three basic steps: denaturation,annealing,and extension.
Which of the statements given above are correct?

How many types of primers are required for the amplification of a gene in $PCR$?

Which of the following steps is $NOT$ used in the creation of Genetically Modified Organisms ($GMO$s)?

What would happen when one grows a recombinant bacterium in a bioreactor but forgets to add antibiotic to the medium in which the recombinant is growing?