FIVE KINGDOM SYSTEM OF CLASSIFICATION
To represent the living organisms according to
evolutionary relationship, the five kingdom system of classification has been
proposed. An American taxonomist "R. H. Whittaker" divided the
living world into five kingdoms such as Monera, Protista, Fungi, Plantae and
Animalia.
CRITERIA OF FIVE KINGDOM CLASSIFICATION
The different characters
considered for differentiating the living organisms into the five kingdom are
as follows
v Cell organization
v Body organization
v Mode of nutrition
v Mode of reproduction
v Life style
CHARACTERISTICS OF KINGDOMS
KINGDOM MONERA
ü Kingdom of
prokaryotes
ü Unicellular, prokaryotic organisms
ü Primitive nucleus
ü Cell wall is rigid
ü Sexual reproduction is absent
ü Asexual reproduction by Budding & Fission
ü Nutrition by autotrophic, heterotrophic &
parasitic
Example:-Archaebacteria, cyanobacteria(BGA)
KINGDOM PROTISTA
ü Kingdom of unicellular eukaryotes
ü Well defined nucleus
ü Both asexual & sexual mode of reproduction are
present
ü Nutrition by photosynthesis, absorption, indigesion or
combination of these
ü Organisms may be motile or non-motile
§ Example:-amoeba,
diatom, euglena, paramecium, some, algae etc.
KINGDOM FUNGI
ü Kingdom of multicellular decomposers
ü Heterotrophic organisms
ü Cell wall composed of chitin
ü Mode of nutrition is saprophytic & parasitic
ü Reserve food material is glycogen
ü Vegetative reproduction by fragmentation, fission
& budding
§ Example:-Mushroom, yeast .etc
KINGDOM PLANTAE
ü Kingdom of multicellular producers
ü Eukaryotes & chlorophyll containing organisms
ü Principle nutritive mode is photosynthesis or
assimilation
ü Cell wall composed of cellulose
ü Reproduction primarily sexual
§ Example:- Multicellular algae (Green, brown & red algae),
mosses, ferns, flowering plants, trees, etc
KINGDOM ANIMALIA
ü Kingdom of multicellular consumers
ü Members are eukaryotic, multicellular heterotrophic
organisms
ü Sensory and nervous system are present
ü Reproduction predominantly sexual
ü Primarily mortile
§ Example:- Sponge, jellyfish, insect, fish,
frog, bird, man etc.
MERITS OF FIVE KINGDOM SYSTEM OF CLASSIFICATION
1) Better placement of some controversial groups like
cyanobacteria, fungi & euglena.
2) System maintains better coherence among the kingdom.
3) This system maintains better relationship among the
kingdom with regards to level of organization and mode of nutrition.
4) It provides a better phylogenetic relationship in the
living world
5) Fungi are separated from algae. Example:-euglena placed in kingdom protista
DEMERITS OF FIVE KINGDOM SYSTEM OF CLASSIFICATION
1) Viruses do not find place or not been included in this
system of classification.
2) Slime mould don’t fit in kingdom protista.
3) Dinoflagellates included in protista are mesokaryotic
not eukaryotic.
4) Slim mould differs from other protists.
CONCLUSION
Before going to study about any living organisms a
detailed knowledge about its systematic classification is essential.
Despite
of more demerits the "Whittaker’s" five kingdom classification is much accepted today
with some modification.