Which of the following statements is incorrect?

The correct answer is Option (1) → Glycogen is a monosaccharide and also known as animal starch.

Carbohydrates are classified by the number of sugar units they give on hydrolysis: monosaccharides cannot be hydrolysed further, disaccharides give two units, and polysaccharides give a large number of units.

• Option (1) Glycogen is a monosaccharide and also known as animal starch. — An incorrect statement. Glycogen is the storage carbohydrate of animals, a large and highly branched polymer of α-D-glucose, so it is a polysaccharide, not a monosaccharide. It is rightly called “animal starch”, but the first half of the statement is false.

• Option (2) The cellulose and glycogen both are composed of glucose. — A correct statement. Cellulose is a straight chain of β-D-glucose units, and glycogen is a branched chain of α-D-glucose units.

• Option (3) Starch consists of two components amylose and amylopectin. — A correct statement. Amylose (15–20%) is water soluble and unbranched; amylopectin (80–85%) is insoluble and branched.

• Option (4) Both maltose and lactose are reducing sugars. — A correct statement. In both, one unit keeps a free hemiacetal group at C1, which can open to an aldehyde and reduce Fehling’s solution and Tollens’ reagent.

NCERT (2026-27 edition):
Classification of Carbohydrates – “… (iii) Polysaccharides: Carbohydrates which yield a large number of monosaccharide units on hydrolysis are called polysaccharides. Some common examples are starch, cellulose, glycogen, gums, etc.”

Glycogen