Eubacteria and archaebacteria have several key biological differences, primarily in the membrane and wall structure of their cells. Eubacteria and archaebacteria have similar general cell structures, but the composition and layout of those cellular components is remarkably different. Archae, like eubacteria, lack interior membranes and use flagella to maneuver but have cell walls comprised of peptidoglycan.
In addition to differing in their cell structures, eubacteria and archaea have different flagella. The flagella found in archaeabacteria derives from the bacterial type IV pili variety, while the flagella of eubacteria comes from the type III secretion system. Eubacteria flagellum is thin and stalk-like in appearance, with a hollow center and comprised of tiny subunits. Those found in archaea, by contrast, are shorter, broader and attached directly to the base. Both organisms reproduce asexually through the process of binary fission, followed by budding and fragmentation. Eubacteria, however, go on to form spores that can remain dormant for several years; this trait is not expressed by archaea. Eubacteria and archaeabacteria share several overlapping habitats, such as hot springs, within the crust of the earth’s surface, and in the bodies of plants, animals and humans. Both are adapted to life in harsh conditions, but eubacteria prefer moist climates, while archaeabacteria enjoy hot and dry locations.