What is the common feature of all the polysaccharides discussed?

The correct answer emphasizes that all the polysaccharides mentioned are composed entirely of glucose units. Polysaccharides are large carbohydrate molecules made up of long chains of monosaccharides, and in many cases, the primary monosaccharide unit is glucose. Examples of polysaccharides that consist entirely of glucose include starch, glycogen, and cellulose. Each of these polysaccharides serves different functions in biological systems, but they all share the characteristic of being formed by repeating glucose units linked together through glycosidic bonds.

This trait is fundamental for their structural and functional roles in living organisms. For instance, starch and glycogen serve as energy reserves, while cellulose provides structural support in plant cell walls. By understanding this common feature, one can appreciate the versatility and importance of glucose as a building block in polysaccharide formation.