Question

Diagnostic feature of insects is
A. Segmented body
B. Chitin in body wall
C. Three pair of legs
D. One pair compound eyes

Answer 1

Hint: The members belonging to the class, Insects possess two pairs of wings, tri-segmented bodies, three pairs of jointed legs, head, thorax, and abdomen, hard exoskeletons, a pair of compound eyes, two antennae and bilateral symmetry.

Complete step by step answer: Insecta is a group that possesses all the organisms that are commonly called insects. The main characteristic of the group Insecta is that they have six legs or simply three pairs of legs. These legs possess joint segments.
-Their body is covered with the exoskeleton. The distinguishing feature of insects is three pairs of legs, because the other features, which are mentioned above can be seen in other organisms. But, insects only have 3 pairs of legs.
-Insects or Insecta are invertebrates that belong to the largest group present within the phylum arthropod. The insects usually comprise a class that is present within the phylum Arthropoda. Insects are found in almost all environments, but only a few species live in the ocean. These insects are dominated by another arthropod group known as crustaceans.
-All known insects hatch from eggs. Insect growth is limited by their inelastic exoskeleton and its development involves a series of molts. The immature stages of the insects usually differ from the adults in structure, habit, and habitat, and contain a passive pupal stage in those groups of insects that go through four-stage metamorphosis.
Hence, the correct option is C.

Note: Insects possess a segmented body that is supported by an exoskeleton, the outer covering is made mostly of chitin which is hard. The segments of the body are differentiated into three units or also called tagmata: a head, a thorax, and an abdomen.