An organism who cells lack organelles and whose DNA is not arranged in chromosomes, but forms a coiled structure called a nucleoid. Prokaryotic organisms are bacteria and blue-green algae. The traditional distinction between prokaryotes and eukaryotes has had to be revised with the discovery of tublin-like, actin-like and histone-like molecules in arch aeons (found, for example, in deep-sea hydrothermal vents) as these proteins were previously considered only to exist in eukaryotes. Tublin refers to a small hollow, cylindrical structure. However, it is believed that eukaryotes evolved from symbiotic associations between prokaryotes.
See Actin, Cell, Cell locomotion, Cytoplasm, DNA, Eukaryote cell (or organism), Flagella, Genome, Histone, Jacob-Monod operon model, Nucleoid, Organelles, Protoplasm, Phototaxis