eukaryote

In biology, one of the three major groupings (domains) into which all life on Earth is divided. Eukaryotes are distinct from the other domains, the archaea and the bacteria (which in the obsolete systematics were combined under the name of prokaryotes) to a comparable extent and are believed to have evolved from ancestors that included genetic traits of both. Eukaryotes are the only one of the three domains that evolved multicellular organisms, but there are single-cell eukaryotes (such as yeast) as well.

The cells of eukaryotes possess a clearly defined nucleus, bounded by a membrane, within which DNA is formed into distinct chromosomes. Eukaryotic cells also contain mitochondria, chloroplasts, and other structures (organelles) that, together with a defined nucleus, are lacking in the cells of prokaryotes. Typically, eukaryotic cells are ten times larger in each dimension than bacteria and archaea.