moneran, any of the prokaryotes constituting the two domains Bacteria and Archaea.
The monerans are distinct from eukaryotic organisms because of the structure and chemistry of their cells. As prokaryotes, they lack the definite nucleus and membrane-bound organelles (specialized cellular parts) of eukaryotic cells. They reproduce principally by transverse binary fission, although transfer of DNA between bacteria is widespread and forms the basis of recombinant DNA technology.