Microorganisms are microscopic, which includes bacteria, fungi, archaea or protists. Microorganisms differ from each other in size and structure, habitat, metabolism, and many other characteristics. Most bacteria are harmless or helpful, but some are pathogens, causing disease in humans and other animals.
|Bacteria||They are single-celled disease-causing micro-organisms. They can be spiral or rod-shaped.|
|Fungi||They are mostly multicellular disease-causing microbes. Bread moulds are common examples of fungi.|
|Protozoa||They mainly include organisms such as Amoeba, Plasmodium, etc. They can be unicellular or multicellular.|
|Virus||Viruses are disease-causing microbes that reproduce only inside the host organism.|
|Algae||They include multicellular, photosynthetic organisms such as Spirogyra, Chlamydomonas, etc.|