What is deoxyribonucleic acid $(DNA)$?

What is $NOT$ present in $DNA$?

Assertion: In a $DNA$ molecule,$A-T$ rich parts melt before $G-C$ rich parts.
Reason: In between $A$ and $T$ there are three $H-$ bonds,whereas in between $G$ and $C$ there are two $H-$ bonds.

$A$ gene is made up of

Which of the following statements is $NOT$ true for $DNA$?

In an experiment,$DNA$ is treated with a compound that intercalates between the stacks of nitrogenous base pairs. As a result,the distance between two consecutive base pairs increases from $0.34 \, nm$ to $0.44 \, nm$. Calculate the length of the $DNA$ double helix (which has $2 \times 10^9 \, bp$) in the presence of a saturating amount of this compound. (in $m$)