Mycoplasma refers to a genus of bacteria that belong to the class Mollicutes. Unlike most bacteria, mycoplasmas lack a cell wall, which makes them unique among prokaryotes. This characteristic contributes to their pleomorphic shape, where they can appear as spherical, filamentous, or irregular forms.
Mycoplasmas are among the smallest known free-living organisms, typically ranging from 0.2 to 0.3 micrometers in diameter. Despite their small size and lack of a cell wall, they possess a plasma membrane and contain genetic material in the form of DNA.