t]
| any organism having as its fundamental structural unit a cell type that contains specialized organelles in the cytoplasm, a membrane-bound nucleus enclosing genetic material organized into chromosomes, and an elaborate system of division by mitosis or meiosis, characteristic of all life forms except bacteria, blue-green algae, and other primitive microorganisms. |

An organism whose cells contain a nucleus. All multicelled organisms are eukaryotes, as is one superkingdom of single-celled organisms. Eukaryotes also have organelles enclosed by membranes. (Compare prokaryote.)
Note: Eukaryotes evolved in a process in which one early prokaryote consumed another, forming a more complex structure.
Note: The word eukaryote comes from the Greek for “true nucleus.”
eukaryote eu·kar·y·ote or eu·car·y·ote (y&oomacr;-kār'ē-ōt, -ē-ət)
n.
A single-celled or multicellular organism whose cells contain a distinct membrane-bound nucleus.