Question

chitin is a polysaccharide found in the exoskeleton of insects. the diagram below shows a chitin monomer. to which major category of biological molecules does chitin belong? proteins, because chitin forms the flexible joints of an insects shell nucleic acids, because chitin provides the blueprint for insect body plans lipids, because chitin serves as an insects insulation from their environment carbohydrates, because chitin is used for structural support in the insects external skeleton

Explanation:

Chitin is a polysaccharide. Polysaccharides are a type of carbohydrate. Proteins are made of amino - acids, nucleic acids carry genetic information, and lipids are for energy storage and insulation. Chitin provides structural support in the insect's exoskeleton which is a characteristic of carbohydrates.

Answer:

carbohydrates, because chitin is used for structural support in the insect's external skeleton