The prefix mono - means "one" and the prefix poly - means "many". How are these meanings related to the terms monomer and polymer

When a molecule is made up of one sugar unit, its called a monomer.

Eg. Glucose, galactose, fructose

When a molecule is made of more than one sugar units, its called a polymer.

Eg. Cellulose, glycogen

Polymers are usually macro molecules.