Which of the following is not present in nucleic acids?

Identify the nucleoside from the following:

The segment of $DNA$ which acts as the instrumental manual for the synthesis of the protein is

$A$ nucleic acid,whether $DNA$ or $RNA$,gives on complete hydrolysis,two purine bases,two pyrimidine bases,a pentose sugar,and phosphoric acid. Nucleotides,which are intermediate products in the hydrolysis,contain:

Which of the following nitrogen bases,either of purine or pyrimidine,does $NOT$ contain an $-NH_2$ group attached to its ring?

In both $DNA$ and $RNA$,the heterocyclic base and phosphate ester linkages are at which positions of the sugar molecule?