Classification of Living Things: Linnaean Classification of Kingdoms

KINGDOM	STRUCTURAL ORGANIZATION	METHOD OF NUTRITION	TYPES OF ORGANISMS	NAMED SPECIES	TOTAL SPECIES (estimate)

Monera	*small, simple single prokaryotic* cell (nucleus is not enclosed by a membrane); some form chains or mats**	absorb food	bacteria, blue-green algae, and spirochetes	4,000	1,000,000

Protista	*large, single eukaryotic* cell (nucleus is enclosed by a membrane); some form chains or colonies**	absorb, ingest, and/or photosynthesize food	protozoans and algae of various types	80,000	600,000

Fungi	*multicellular filamentous form with specialized eukaryotic* cells**	absorb food	funguses, molds, mushrooms, yeasts, mildews, and smuts	72,000	1,500,000

Plantae	*multicellular form with specialized eukaryotic* cells; do not have their own means of locomotion**	photosynthesize food	mosses, ferns, woody and non-woody flowering plants	270,000	320,000

Animalia	*multicellular form with specialized eukaryotic* cells; have their own means of locomotion**	ingest food	sponges, worms, insects, fish, amphibians, reptiles, birds, and mammals	1,326,239	9,812,298

NOTE: A growing number of researchers now divide the Monera into two distinct kingdoms: Eubacteria (the true bacteria) and Archaebacteria (bacteria-like organisms that live in extremely harsh anaerobic environments such as hot springs, deep ocean volcanic vents, sewage treatment plants, and swamp sediments). Viruses, prions, and other non-cellular entities are not included in the five kingdoms.
The numbers of named and estimated total species were derived from Gibbs, W. Wayt (2001) "On the Termination of Species", Scientific American Vol. 285, No. 5.