Introduction about Microorganisms.
We see a  lot of organisms around us.

Some organisms are bigger enough to see with naked eyes like an elephant, a cow, a banyan tree, or a  rose plant.

But there are some other organisms which are not visible with naked eyes. We can see these organisms with the help of microscope.
These tiny organisms are called microorganisms.  These are also called microbes.
 Microbes were first observed by A. V. Leeuwenhoek under a microscope. Microorganisms can survive in all types of habitats or we can say they are present everywhere They are present in air, water, soil, hot water streams, glaciers, Volcanoes and inside the bodies of plants and animals. They are also present in various parts of human body. They are also present in dead and decaying materials. Most of the microbes are harmless. Some microbes are useful to us. While some microbes are harmful to us because they cause diseases.
Micro organisms are of five types:


Algae
Fungi
Protozoa
Bacteria
Virus