| | + | A [[cell]] that lacks a defined nucleus and [[organelle]]s. Bacteria and blue-green algea are composed of prokaryotic cells and are called [[prokaryotes]].<ref>http://biotech.icmb.utexas.edu/search/dict-search.html</ref> Prokaryotes are single-cell organisms, although some can form colonies.<ref>http://www.iscid.org/encyclopedia/Prokaryotic_Organisms</ref> The prokaryote DNA is structurally simple and frequently is composed of only one circular chromosome.<ref>Brown, T.A. "Genomes" Garland Science ; c2002.</ref> |