Organisms whose cells do not have a nucleus in which DNA is housed and which lack many of the organelles found in more advanced cells. The kingdom of Monera or Prokaryotae is composed of single-celled prokaryotes. (Compare eukaryotes.)

The New Dictionary of Cultural Literacy, Third Edition Edited by E.D. Hirsch, Jr., Joseph F. Kett, and James Trefil. Copyright © 2002 by Houghton Mifflin Company. Published by Houghton Mifflin. All rights reserved.