Biology Instinct Essay, Research Paper

Insects are neumerout

invertebrate animals that belong in the Phylum

Arthropoda and Class Insecta.

The class Insecta is divided into 2 subclasses:

Apterygota, or wingless

insects, and Pterygota, or winged insects. Subclass

Pterygota is futher divided

on basis of metamorphosis. Insects that have

undergone incomplete metamorphosis

are the Exopterygota. Insects that undergo

complete metamorphosis are the

Endopterygota.

Insects have an outer bilateral exoskeleton to which the

muscles are attached

to and provides protection for internal organs. The

body is divided into 3

main parts which are the head, which include mouthparts,

eyes, and antennae;

thorax, which operate the jointed legs and /or wings;

and abdomen, which has

organs for digested food, reproducing, and getting

rid of waste products.

The major systems in insects are the circulatory,

respiratory, nervous,

muscular, digestive, and reproductive systems. In the

circulatory system,

blood is pumped by the heart in a tube to the aorta,

the head, and to other

organs then enters the ostia openings along the sides

of the tube back to the

heart. The respiratory systems carries O2 to cells

and takes away CO2 from

cells through branching out to call cells of body.

The nervous system consists

of a brain receiving information from eyes, antennae,

and controls the whole

body and 2 nerve cords containing ganglia fused together

to control activities

of the segment without the help of the brain. insect

muscular system is made

up of a

few thousand samll but string muscles allowing

the insect to carry objects

heavier than it. The digestive system is basically

a long tube where food

enters the mouth to the crop where it is stored, gizzard

where it is grinded,

stomach where it is digested, then the undigested parts

and wastes are moved

to the intestine, colon then released at the anus. And

in the reproductive

system, a new individual is produced sexually when the

female eggs produced in

the ovaries united with male sperm produced in the

testes.

Both man and insect live almost everywhere, eat all kinds of food,

and use

all kinds of materials to build homes so they constantly live in

conflict.

Some insects seriously affect man’s health and are parasitic on

man and other

animals. insects that feed on human or animal blood can carry

disease in their

salivary juices and spread the disease to other animals.

Many insects irritate

us without disturbing our health. Some bite and sting,

and some people are

allergic to them and some insects are injurious to our

agricultural crops,

food products, clothing, and wooden buildings. So far

man has only partial

success in defending against insects. But some insects

species are beneficial

to man. The honey bee, for example, supplies us with

honey and the silkworm

supplies us with silk. So bugs really aren’t that

bad.