The starch found in plants differs structurally from glycogen found within animal tissues despite both being polymers primarily composed of glucose. 
i. What is their main structural difference? 
ii. Elaborate on their roles within the organisms in which they are found.

• A. i. Starch is made up of both linear amylose and branched amylopectin (which branches every 20–30 glucose units), while glycogen is more highly branched, with branches occurring every 8–12 glucose units.ii. Both provide structural support to plant and animal cells respectively.
• B. i. Starch is composed of glucose units linked by α-1,4-glycosidic bonds, while glycogen is composed of glucose units with both α-1,4- and α-1,6-glycosidic bonds.ii. Both provide structural support to plant and animal cells respectively.
• C. i. Starch is made up of both linear amylose and branched amylopectin (which branches every 20–30 glucose units), while glycogen is more highly branched, with branches occurring every 8–12 glucose units.ii. Starch is an energy storage in plants, while glycogen is a secondary long-term energy storage in animal cells.
• D. i. Starch is composed of glucose units linked by α-1,4-glycosidic bonds, while glycogen is composed of glucose units with both α-1,4- and α-1,6-glycosidic bonds.ii. Starch is an energy storage in plants, while glycogen is a secondary long-term energy storage in animal cells.

Answer: (C)