Definition and important characters of arthopods

DEFINITION:- Entomology is the branch of science which deals with the study of insects.

INSECTS:- Insects are the tracheated arthropods. Thus insects can be defined as the thacheated arthropods whose body is divided in head, thorax, and abdomen .The head consist of sensory organ( that are pair of antennae) the thorax consist of organs of locomotion( three pair of legs and usually 1-2 pairs of wings) and the abdomen consist of reproductive organs.

IMPORTANT CHARACTERS OF PHYLUM ARTHOPODA:-

This is the largest phylum in animal kingdom which constitute about 80% of all species in animal kingdom. The main character are as following:-

a.     Body is divided into segments the segments usually grouped into 2-3 distinct region.

b.    Bi-laterally symmetrical animal.

c.     Paired segmented appendages.

d.    The circulatory system is open type in which blood flows freely within body cavity.

e.     Excretion by mean of malpighian tubules.

f.       Respiration by mean of trachea or spiracles.

g.     Metamorphosis take place in their life cycle.