The unit of nucleic acid is .....

Select the correct option for a nucleotide.

The presence or absence of hydroxyl group on which carbon atom of sugar differentiates $RNA$ and $DNA$?

$S$ - Statement: $RNA$ contains ribose type of pentose sugar.
$R$ - Reason: $DNA$ contains ribulose type of pentose sugar.

What type of sugar is present in the structure of $DNA$?

Thymine or methylated uracil is present in nucleic acids. It should be .......