SIze comparison of microorganisms Meters Visibility scale Relative size of microbes 10 _1, um or 1 mm Naked ey Prokaryotes um 10w Bacillus megaterium 1,000 nm or 1 um Eukaryotes cherichia coli 100nm Light microscope Mycoplasma 10 10 nm Virus Vil Iruses 10-9 1 nm Electron microscopesize comparison of microorganisms Meters Visibility scale Relative size of Microbes Prokaryotes Eukaryotes Viruses Naked eye Light microscope Electron microscope