Eukaryotic cells may be either unicellular or multicellular. For a cell to be identified as eukaryotic, it must contain a membrane-bound nucleus where the genetic information is stored. Any cell that meets this criteria is eukaryotic, regardless of whether it is unicellular or multicellular. Yeast and amoebas are the most common examples of unicellular eukaryotes. All animals and plants are multicellular eukaryotes.