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 acti
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.