Micro organisms include
• all viruses } no cell structure
• all bacteria and blue green algae } procaryotic cell structure
• all protists, and } eucaryotic cell
• certain fungi and algae } structure.
Although most micro organisms are unicellular, some fungi and algae in this group are multicellular. The simplest and smallest micro organisms are the viruses which do not have a cell structure. Bacteria and blue green algae are larger micro organisms with a very simple CE structure where the nucleus is not enclosed within a membrane. The protists, fungi and algae are larger than bacteria and have a complex cell structure with a nucleus that is confined within a membrane. Most micro organisms survive unfavourable conditions by forming spores.
