Definition and Classification

Microorganisms, or microbes, are tiny organisms that cannot be seen with the naked eye. Some, like the fungus on bread, can be observed with a magnifying glass, while others require a microscope for viewing. Microorganisms are classified into four main groups: bacteria, fungi, protozoa, and some algae. Viruses, though microscopic, are distinct from other microorganisms as they can only reproduce inside the cells of a host organism (bacteria, plant, or animal).

Types of Microorganisms

1.Bacteria: Single-celled organisms that can be found in various environments. They play crucial roles in processes like nitrogen fixation, decomposition, and fermentation.

2.Fungi: Includes yeasts, moulds, and mushrooms. They can be single-celled or multicellular and are important decomposers in ecosystems.

3.Protozoa: Single-celled organisms that can cause diseases like dysentery and malaria.

4.Algae: Can be single-celled or multicellular and are often found in aquatic environments.