Whittaker’s systems of classification, prokaryotes are placed in the kingdom Monera. Kingdom Monera includes all prokaryotes. They are basically unicellular but can be mycelial, colonial and filamentous. A prokaryote is a single-celled organism that lacks a membrane-bound nucleus (karyon), mitochondria, or any other membrane-bound organelle. Monera is a kingdom that contains unicellular organisms with a prokaryotic cell organization, such as bacteria. The taxon Monera was first proposed as a phylum by Ernst Haeckel in 1866.