Monera (Greek - μονήÏης (monḗrÄ“s), "single", "solitary") (/məˈnɪərÉ™/ mÉ™-NEER-É™) was a kingdom that contained unicellular organisms with a prokaryotic cell organization (having no nuclear membrane), such as bacteria. They are single-celled organisms with no true nuclear membrane (prokaryotic organisms).