Question

Pentose and hexose are the most common
(a) Oligosaccharide
(b) Disaccharide
(c) Monosaccharide
(d) Polysaccharide

Answer 1

Hint: The molecular formula of pentose and hexose are $C_5{H}_{10}{O}_5$ and $C_6{H}_{12}{O}_6$ respectively. They are similar to the basic formula of monosaccharide.

Complete step by step answer:
Pentose and hexose are common types of monosaccharides. Pentose is a five-carbon monosaccharide, whereas hexose contains six carbon atoms. The chemical formula of both pentose and hexose is similar to the basic formula of monosaccharide, i.e. $C_n{H}_{2n}{O}_n$.
So, the correct answer is, ‘(c) Monosaccharide’.

Additional Information: Pentose is a five-carbon molecule with molecular formula $C_5{H}_{10}{O}_5$. Whereas, a hexose is a six-carbon compound whose molecular formula is $C_6{H}_{12}{O}_6$. Both pentose and hexose are monosaccharides. Monosaccharides are the simplest form of sugar with the basic formula as $C_n{H}_{2n}{O}_n$. Glucose is a common example of hexose and the most common pentose are ribose, fructose, etc. The structures of pentose and hexose are given below,

Now, let us know more about the other three sugars in the question.
Oligosaccharide: These are the chains of small monosaccharides (usually 2-9).
Disaccharide: Disaccharides are formed by a combination of two monosaccharides. Some examples of disaccharides are- sucrose, maltose, etc.
Polysaccharide: These are complex carbohydrates. These consist of a polymer of large numbers of monomers. Glycogen, starch, cellulose, etc. are examples of polysaccharides.

Note: The molecular formula and structures of pentose and hexose are similar to monosaccharides. They don’t show any noticeable similarity with oligosaccharide, disaccharide, or polysaccharide.