Final answer:
Most green plants use starch as their major energy storage, which is a polymer of glucose. Starch and glycogen are energy storage polymers, while cellulose is a structural component in plant cell walls.
Step-by-step explanation:
The major energy storage in most green plants is starch. Starch is a polysaccharide and a polymer of glucose, serving as a storage form of energy in plants. It is composed of two types of polymers: amylose, which is linear, and amylopectin, which is branched.
In comparison, animals store energy in the form of glycogen, which is also a branched polymer of glucose but more highly branched than amylopectin.
Cellulose is another glucose polymer, which is a structural component in plant cell walls. Unlike starch and glycogen, cellulose has a very stiff rod-like structure with glucose units linked through ß-1,4-glycosidic bonds, and it provides rigidity and strength to the plant cell walls.