Read the passage carefully and answer the questions.

Carbohydrates such as cane sugar, glucose, starch etc. belong to a class of naturally occurring organic compounds. Structurally these are polyhydroxy aldehydes or ketones or the compounds which produce such units on hydrolysis. Carbohydrates which are sweet in taste are called sugars. Theses sugars can be reducing or non-reducing. Monosaccharides cannot be hydrolyzed to simpler units whereas Oligosaccharides yield two to ten monosaccharide units on hydrolysis. Polysaccharides yield large number of monosaccharide units on hydrolysis. This class of biomolecules is essential for living systems as they serve as storage molecules in plants and animals. In addition, they provide raw materials for important industries like furniture, textiles, paper, lacquers and breweries. Two aldopentose form important constituents of nucleic acids. Carbohydrates are also called saccharides (Greek: sakcharon which means sugar). Sugar which is used in household and in milk also comes under this class of biomolecules.

Among below given carbohydrates, which one is not a polysaccharides?

Ribose

The correct answer is Option (4) → Ribose

The complete statement is Ribose is not a polysaccharide.

Starch – Starch is a polysaccharide because it is made up of many glucose units joined together. It serves as a storage carbohydrate in plants.

Cellulose – Cellulose is also a polysaccharide. It consists of long chains of glucose and forms the structural component of plant cell walls.

Glycogen – Glycogen is a polysaccharide made of numerous glucose units and acts as the storage carbohydrate in animals.

Ribose – Ribose is not a polysaccharide. It is a monosaccharide (a single sugar unit), specifically an aldopentose, and is an important component of nucleic acids like RNA.