Final answer:
Lactose is composed of glucose and galactose and is found in milk. Maltose is formed from two glucose molecules, while sucrose is made up of glucose and fructose. Sucrose can be found in sugarcane and sugar beets.
Step-by-step explanation:
Lactose is a disaccharide composed of the monomers glucose and galactose. It is naturally found in milk.
Maltose, also known as malt sugar, is a disaccharide formed by the dehydration reaction between two glucose molecules.
Sucrose, or table sugar, is the most common disaccharide. It is composed of the monomers glucose and fructose. Sucrose is found in various plant sources, such as sugarcane and sugar beets.