There are five major groups of microorganisms which are:
→ Bacteria - They are single celled disease-causing micro-organisms. They can be spiral or rod- shaped.eg: Blue-green bacteria.
→ 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.eg:HIV
→ Algae - They include multicellular, photosynthetic organisms such as Spirogyra, Chlamydomonas, etc.