Question

Diagnostic feature of insects is
A) Segmented Body
B) Chitin body wall
C) Three pairs of legs
D) One pair compound eyes

Answer 1

Insects has a tracheal respiratory system in which the exchange of gases takes place at the tracheoles by the diffusion process. In this structure, the tracheal conveys oxygen openly to the body cells and does not require blood to carry it.

Complete answer:
Let’s first need to know about these features.
A. Insecta is the group which includes all the organisms commonly called as insects. The features of Insecta are that they have six forelegs or three pairs of legs.
B. Algae are eukaryotic organisms ranging from unicellular microalgae to multicellular organisms such as giant kelp. In wide-ranging, algae are plant-like bacteria that are divided into two parts photosynthetic and aquatic.
C. Associates of the family of Insecta have two pairs of arms, three pairs of jointed legs, tri-segmented bodies, head, thorax, and stomach, hard exoskeletons, a couple of complex senses, a pair of antennae and bilateral symmetry. But the analytic character of pests is three pairs of legs, because the other structures, which are revealed on top, also can be seen in other animals. But, only insects have 3 pairs of legs.
D. Penicillin is the antibiotic that was discovered from the fungus molds. These are used to treat bacteria and it was the first antibiotics that were used by the doctor.

So, the right answer is option (C) Three pairs of legs.

Note:
Insects are very useful to pollination and in forensic science it is useful to determine the time of the death of the person and its study in forensic science is also known as Entomology.