Microorganisms/Microbes The word“ microbe” comes from the greek words mi秋kros, meaning small, and bios, meaning life. So microorganisms/microbes are small living things that are too small to be seen with the unaided eye Microorganisms were probably the first organisms to appear on the earth. However, these organisms were not seen until about 3 centuries ago when lenses powerful enough to make them visible were made Viruses, bacteria, fungi, protozoa and some algae are all in this category.•The word “microbe” comes from the Greek words mikros, meaning small, and bios, meaning life. So microorganisms/microbes are small living things that are too small to be seen with the unaided eye. •Microorganisms were probably the first organisms to appear on the earth. •However, these organisms were not seen until about 3 centuries ago when lenses powerful enough to make them visible were made. •Viruses, bacteria, fungi, protozoa and some algae are all in this category. Microorganisms/Microbes