Two nucleotides are joined together by a linkage known as:

Which base is not present in the $DNA$ structure?

Select the correct sequence of True $(T)$ and False $(F)$ statements from the following:
$(i)$ $\text{Pentose sugar} + \text{base} \rightarrow \text{Nucleotide}$
$(ii)$ $\text{Nucleotide} + \text{phosphate} \rightarrow \text{Nucleoside}$
$(iii)$ $DNA$ contains four bases $A$,$G$,$C$ and $T$
$(iv)$ $RNA$ contains four bases $A$,$G$,$C$ and $U$.

Nucleic acid is a polymer of

Which of the following is correct about $H$-bonding in $DNA$?

Which one is a purine base?