Question

Match the following.

List I	List II (Monomer)
Sucrose	${\rm{\beta }}$-D-Galactose and ${\rm{\beta }}$-D-Glucose
Cellulose	${\rm{\alpha }}$-D-Glucose and ${\rm{\beta }}$-D-Fructose
Starch	${\rm{\beta }}$-D-Glucose
Lactose	${\rm{\alpha }}$-D-Glucose

A. A-i, B-ii, C-iii, D-iv
B. A-ii, B-i, C-iii, D-iv
C. A-ii, B-iii, C-iv, D-i
D. A-iv, B-iii, C-i, D-ii

Answer 1

To solve this we must know that the complex carbohydrates given in list-I are made up of which monomers. A small molecule that reacts with the similar molecule to form a larger molecule is known as a monomer.

Complete answer:
We know that a small molecule that reacts with a similar molecule to form a larger molecule is known as a monomer.
We are given four complex carbohydrates sucrose, cellulose, starch and lactose.
Sucrose is a disaccharide. Sucrose is naturally occurring sugar. It is obtained from plants. Disaccharide means it is made up of two monosaccharides. The monosaccharides that make up the sucrose are ${\rm{\alpha }}$-D-Glucose and ${\rm{\beta }}$-D-Fructose.
Thus, the monomer of sucrose is ${\rm{\alpha }}$-D-Glucose and ${\rm{\beta }}$-D-Fructose. Thus, A-ii.
Cellulose is an organic compound. Cellulose is the main constituent of the cell wall of green plants. It is a polysaccharide that consists of ${\rm{\beta }}$-D-Glucose units.
Thus, the monomer of cellulose is ${\rm{\beta }}$-D-Glucose. Thus, B-iii.
Starch is a polymeric carbohydrate. Starch is produced by green plants as an energy storage. It consists of the number of ${\rm{\alpha }}$-D-Glucose units that are linked by glycosidic bonds.
Thus, the monomer of starch is ${\rm{\alpha }}$-D-Glucose. Thus, C-iv.
Lactose is a disaccharide. Lactose makes up around $2 - 8\%$ of milk. It is made up of two monosaccharides ${\rm{\beta }}$-D-Galactose and ${\rm{\beta }}$-D-Glucose.
Thus, the monomers of lactose are ${\rm{\beta }}$-D-Galactose and ${\rm{\beta }}$-D-Glucose. Thus, D-i.

**Thus, the correct option is (C) A-ii, B-iii, C-iv, D-i.

Note:**
Sucrose and lactose are disaccharides. Disaccharides are formed when two monosaccharides are joined by glycosidic bonds. Cellulose and starch are polysaccharides. Polysaccharides are long chains of monosaccharides. The monosaccharides are linked by glycosidic bonds.