Solution: There are five major groups of micro-organisms:
(i). Bacteria - They are single celled disease-causing micro-organisms. They can be spiral or rodshaped.
(ii). Fungi - They are mostly multicellular disease-causing microbes. Bread moulds are common examples of fungi.
(iii). Protozoa - They mainly include organisms such as Amoeba, Plasmodium, etc. They can be unicellular or multicellular.
(iv). Virus -Viruses are disease-causing microbes that reproduce only inside the host organism.
(v). Algae - They include multicellular, photosynthetic organisms such as Spirogyra, , etc
