Which of the following is a heteropolymer?
(a) Cellulose
(b) Peptidoglycan
(c) Starch
(d) Glycogen

Hint: These are heteropolymers formed from amino acids and carbohydrates. These are found in the bacteria’s cell membrane as an outermost covering.

Complete step by step answer:
Peptidoglycan is a heteropolymer. These are made up of amino acids and carbohydrates and have different monomers. That is why they are said to be heteropolymers. Heteropolymers are substances that are formed from two or more different polymers. In other words, a heteropolymer is a polymer in which the monomers are not identical.
- A giant molecule made up of many smaller molecules namely monomers, the giant molecule is called a polymer.
- If all the monomers are identical in a molecule then that polymer is a homopolymer.
- In the walls of plant cells cellulose is the main substance that is helping plants to remain stiff and upright. Humans cannot digest cellulose and can not be digested by humans, but it is important in the diet as fiber.
- Starch is a polymeric carbohydrate consisting of numerous glucose units joined by glycosidic bonds. This is produced by most green plants as energy storage and is made up of similar glucose molecules so it is a homopolymer.
- Glycogen may be a multibranched polysaccharide of glucose that is a sort of energy storage in animals, fungi, and bacteria. This polysaccharide structure represents the main storage form of glucose in the animal body.
So, the correct answer is, '(b) Peptidoglycan'.

Note:
- Peptidoglycans are generally found in the cell membrane of the bacteria as an outer covering membrane of the bacteria cell.
- Proteins are made from up to twenty different amino acids, so proteins are heteropolymers.