Polymerase chain reaction is most useful in

Silencing of specific mRNA in RNAi is by

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.

The technique of bombarding plant cells with high velocity microparticles of gold or tungsten,coated with $DNA$,is known as:

$A$ transformed bacterium with a human gene fails to produce the desired protein. The reason could be:

$A$: To extract $RNA$ from tomato cells,it must first be treated with cellulase,protease,and then deoxyribonuclease.
$R$: Deoxyribonuclease will digest $DNA$ while $RNA$ will be intact.