Lactose, a sugar in milk, is composed of one glucose molecule joined by a glycosidic linkage to one galactose molecule. How is lactose classified?

as a disaccharide

Explanation:

A monosaccharide is a class of sugars that can not be hydrolyzed into smaller units. They are the simplest and smallest unit of sugars. They are also the building block of complex sugars.

Disaccharides are the class of sugar that is made by the joining of two monosaccharides. These monosaccharides are joined together by glycosidic linkage.

For example, lactose is a disaccharide which is made up of glucose and a galactose molecule which are joined together by a glycosidic bond.