Define the following terms: Nucleoside and Histones.

(N/A) $1$. Nucleoside: $A$ nucleoside is formed when a nitrogenous base is linked to a pentose sugar through an $N$-glycosidic linkage.
$2$. Histones: Histones are a set of positively charged basic proteins. They are rich in the basic amino acid residues,specifically lysines and arginines.