In $DNA$,the linkages between different nitrogenous bases are

Which base is present in $RNA$ but absent in $DNA$?

Which of the following bases are present in both $DNA$ and $RNA$?

Which from the following nitrogen bases of nucleic acids is derived from purine?

Which moieties of nucleosides are involved in the formation of phosphodiester linkages present in dinucleotides? What does the word 'diester' in the name of linkage indicate? Which acid is involved in the formation of this linkage?

$RNA$ is different from $DNA$ because it contains ...