Explanation

The nucleotide is formed by the union of a phosphate group with a nucleoside. A nucleoside contains a sugar molecule along with an organic nitrogenous base. Thus, a nucleotide contains a organic nitrogenous base (purine or pyrimidine) along with a sugar molecule and a phosphate group, $i.e.,$ Nucleoside=Sugar molecule+Organic nitrogenous base. Nucleotide=Nucleoside+Phosphate group.