Identify the nitrogenous base of nucleic acid from the following that has a double-ring structure.

The total number of correct statements regarding the nucleic acids is..............
$A$. $RNA$ is regarded as the reserve of genetic information.
$B$. $DNA$ molecule self-duplicates during cell division.
$C$. $DNA$ synthesizes proteins in the cell.
$D$. The message for the synthesis of particular proteins is present in $DNA$.
$E$. Identical $DNA$ strands are transferred to daughter cells.

What is the unit of base-sugar-phosphate in nucleic acids called?

Which one is a purine base?

Which of the following is not a type of $RNA$?

The number of hydrogen bonds between guanine and cytosine; and between adenine and thymine in $DNA$ is