Question

What is the criteria of classification for organisms belonging to Kingdom Monera and Protista?

Answer 1

Criteria for organisms belonging to Kingdom Monera and Protista is the presence and absence of nucleus and cell bound organelles. Monerans and protists both are single celled organisms but they differ being prokaryotes and eukaryotes.

Complete answer:
Linnaeus gave two kingdom classification systems after R.H. Whittaker in 1959 proposed a five kingdom classification based on Linnaeus' two kingdom classification. The main criteria for classification of Kingdom Monera and Protista is the presence or absence of well-defined nucleus and cell-bound organelles.

Organisms belonging to the Kingdom Monera and Protista both are single-cell life forms but they are distinct from each other. In the five kingdom classification system organisms are grouped into five kingdoms, that is Monera Protista fungi, plant and animal based on cell structure, mode and source of nutrition and body organisation. All the unicellular prokaryotic organisms are added into the Kingdom Monera and all Eukaryotic unicellular organisms are added to the Kingdom Protista.
These kingdoms are broadly divided on the basis of cell wall presence or absence of membrane bound organelles and unicellular or multicellular organisms.

Monerans are the unicellular prokaryotic single celled organisms and protists are unicellular Eukaryotic cells organisms.

Note:
Five kingdom classification of these living organisms are based on diversity and evolutionary history ,the criteria based on cell structure of the cell, mode of nutrition, unicellularity or multicellularity. So in Monera these cells are simpler and lack Complex organelles that is they are prokaryotic organisms or cells while in Protista Eukaryotic unicellular organisms or cells are added.