The presence of a nucleus gives eukaryotes their name, which comes from the Greek ευ (eu, well) and κάρυον (karyon, nut or kernel). Eukaryotic cells also contain other membrane-bound organelles such as mitochondria and the Golgi apparatus. In addition, plants and algae contain chloroplasts.Eukaryotic organisms may be unicellular, or multicellular. Only eukaryotes have many kinds of tissue made up of different cell types. eukaryote (/juːˈkaeri.juːˈkæri/ oʊt /or/ juːˈkaeriət-JUːˈKæRIəT-yoo-karr ee oht-OR-yoo-karr) ee ət is any organism whose cells contain a nucleus and other organelles enclosed. Within membranes eukaryotes belong to The taxon Eukarya. or eukaryota