Lack membrane-bounded organelles including a nucleus. Peptidoglycan is found in procaryotic cell walls but not in eucaryotic cell walls.
Bacteria are unicellular and most multiply by binary fission.
Species are differentiated by morphology, chemical composition, nutritional requirements, biochemical activities, and source of energy. Most bacteria are from 0.20 to 2.0 m m in diameter and from 2-8 m m in length. B. Shape 1. Single - Most b. Long filamentous appendages that propel bacteria.