What is the criterion for the classification of organisms as belonging to Kingdom Monera or Protista?
Cell structure is the criteria used for classification of organisms as belonging to Kingdom Monera or Protista. The organisms belonging to both Monera or protista are single celled or unicellular organisms. But in Monera, a well defined nucleus is not present i.e. the cell is prokaryotic and on the other hand in the protista nucleus is well defined i.e. the cell is eukaryotic.
