page_title: Bacterial cellular morphologies
hierarchical_section_title: Bacterial cellular morphologies
context_page_description: Bacteria and Archaea are classified by direct examination with the light microscope according to their morphology and arrangement.
  The basic morphologies are spheres and round-ended cylinders. But there may be others such as helically twisted cylinders, cylinders curved in one plane and unusual morphologies. Arrangements include pairs, tetrads, clusters, chains and palisades.
context_section_description: Bacteria and Archaea are classified by direct examination with the light microscope according to their morphology and arrangement.
  The basic morphologies are spheres (coccus) and round-ended cylinders (bacillus). But there may be others such as helically twisted cylinders (spirochetes), cylinders curved in one plane (selenomonads) and unusual morphologies (such as the square, flat box-shaped cells of the archaean genus Haloquadratum). Arrangements include pairs, tetrads, clusters, chains and palisades.
caption: Bacteria display a large diversity of cell morphologies and arrangements