Macromolecule chitin is
A. Nitrogen-containing polysaccharide.
B. Phosphorus-containing polysaccharide.
C. Sulfur-containing polysaccharide.
D. Simple polysaccharide.

Hint: The chitin makes the major components of the cell walls of the fungus. Also, the exoskeletons of Arthropods consist of Chitin. It is a fibrous substance consisting of polymers of N-glucosamine.

Complete step by step answer: Chitin is a long-chain polymer that constitutes many biological components including exoskeletons of Arthropods like crustaceans and insects, cell walls of fungi, beaks, and shells of cephalopods, etc. it is comparable to protein keratin. Chitin is also used in several medicines and biotechnological purposes. The structure of chitin is composed of monomers of nitrogen and glucose. Thus, it is a nitrogen-containing polysaccharide and derivative of modified glucose molecules. Chitin is the second abundant polysaccharide to cellulose. Moreover, chitin is a biodegradable molecule that can be degraded and dissolved over time. This makes it usable in various industrial applications like in the making of surgical thread.
Therefore, the right answer is option A. Macromolecule chitin is a nitrogen-containing polysaccharide.
Additional information:
Chitin is related to cellulose but it is different from it by a substitution that occurs on glucose molecules. In chitin, instead of a hydroxyl group, there is an amyl group that consists of carbon and nitrogen attached to glucose molecules. The chitin is when combined in matrix forms with various other compounds or other chitin molecules, it makes a very hard substance. This is because of all the weak interactions between nearby molecules.

Note: Chitin is a very important polysaccharide that provides shape to the fungi cells and protects them by making a hard covering around them. Also, the chitin in cephalopods is used to form a beak that is used to bite through the hard shells of their prey.