[yoo-kar-ee-oht, -ee-uh 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.
Origin of eukaryote
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018
- any member of the Eukarya, a domain of organisms having cells each with a distinct nucleus within which the genetic material is contained. Eukaryotes include protoctists, fungi, plants, and animalsCompare prokaryote
from eu- + karyo- + -ote as in zygote
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012
Word Origin and History for eukaryotic
Online Etymology Dictionary, © 2010 Douglas Harper
- A single-celled or multicellular organism whose cells contain a distinct membrane-bound nucleus.
The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.
- An organism whose cells contain a nucleus surrounded by a membrane and whose DNA is bound together by proteins (histones) into chromosomes. The cells of eukaryotes also contain an endoplasmic reticulum and numerous specialized organelles not present in prokaryotes, especially mitochondria, Golgi bodies, and lysosomes. The organelles are enclosed in a three-part membrane (called a unit membrane) consisting of a lipid layer sandwiched between two protein layers. All organisms except for bacteria and archaea are eukaryotes. Compare prokaryote.
The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
Eukaryotes evolved in a process in which one early prokaryote consumed another, forming a more complex structure.
The word eukaryote comes from the Greek for “true nucleus.”
The New Dictionary of Cultural Literacy, Third Edition Copyright © 2005 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.