Cellulose is a naturally occurring linear polymer composed of units of:

Step-by-step solution

Cellulose is a straight-chain polysaccharide composed entirely of -D-glucose units. These units are joined together by -1,4-glycosidic linkages, where the C1 of one glucose unit is connected to the C4 of the adjacent glucose unit. Therefore, the monomeric unit of cellulose is -glucose. Answer: -glucose