If an isolated strain of $DNA$ is kept at $82-90^{\circ}C$,then

The $DNA$ molecule has a uniform diameter due to which of the following?

Degeneration of $DNA$ after heating can be studied by comparing

Which nitrogenous base is present in $RNA$ but not in $DNA$?

Which of the following nitrogenous bases is $NOT$ present in $RNA$?

If the distance between two consecutive base pairs in a $DNA$ molecule is $0.34 \ nm$ and the total number of base pairs in a typical mammalian cell is $6.6 \times 10^9 \ bp$,what is the approximate length of the $DNA$ (in $m$)?