Answer:
1. glucose
Explanation:
Glycogen, starch, and cellulose are polysaccharides consisting of several (thousands) glucose units joined together by glycosidic linkage or bond.
Glucose is the most abundant monosaccharide in nature and it is primarily synthesized by plants and other photosynthetic organisms.
Hence, the only option that is not a polysaccharide is option 1.
