prokaryote

In biology, an organism whose cells lack organelles (specialized segregated structures such as nuclei, mitochondria, and chloroplasts). Prokaryote DNA is not arranged in chromosomes but forms a coiled structure called a nucleoid. The prokaryotes comprise the bacteria (including the cyanobacteria), formerly known as blue-green algae and the archaea; in contrast, organisms with a nucleus are known as eukaryotes.