False-colour scanning electron micrograph of Mycoplasma sp, member of a large group of microorganisms with an unclear relationship to bacteria. Mycoplasmas are the smallest cellular organisms known (diameter 0.3-0.9 microns). Unlike bacteria they lack a true cell wall & hence display a wide variety of forms including spherical, pear-shaped, branched or unbranched filaments. The mode of reproduction is thought to be binary fission. Many species are parasites, living on the moist mucosal membranes of humans. Others are pathogens, such as this species, which is associated with vaginal & pulmonary infections. Mag: X6,750 (at 35mm size)