If a recombinant $DNA$ bearing a gene for ampicillin resistance is transferred into $E. coli$ cells and the host cells are spread on agar plates containing ampicillin,then:

Which statements are correct for gel electrophoresis to separate $\text{DNA}$ fragments?
$(a)$ $\text{DNA}$ is a negatively charged molecule and so it is loaded on the gel towards the anode terminal.
$(b)$ $\text{DNA}$ fragments travel along the surface of the gel whose concentration does not affect the movement of $\text{DNA}$.
$(c)$ Smaller the size of $\text{DNA}$ fragments,larger is the distance it travels through it.
$(d)$ Pure $\text{DNA}$ can be visualized directly by exposing it to $\text{UV}$ radiation.

How does one visualise $DNA$ on an agarose gel?

When $DNA$ fragments stained with ethidium bromide are viewed under $UV$ radiation,how do they appear?

Ethidium bromide stained agarose gel is exposed to $.......,$ to observe $\text{DNA}$ as bright orange coloured bands.

The correct order of steps in Polymerase Chain Reaction $(PCR)$ is