TNPSC Free Notes Biology -Classification of Living Organisms – 1

இந்தக் கட்டுரையில், TNPSC குரூப் 1, குரூப் 2, குரூப் 2A, குரூப் 4 மாநிலப் போட்டித் தேர்வுகளான TNUSRB, TRB, TET, TNEB போன்றவற்றுக்கான  முறைகள் இலவசக் குறிப்புகளைப் பெறுவீர்கள்.தேர்வுக்கு தயாராவோர் இங்குள்ள பாடக்குறிப்புகளை படித்து பயன்பெற வாழ்த்துகிறோம்.

Classification of Living Organisms – 1

Introduction:
Taxonomy:
 Taxonomy is the branch of biology that deals with the study of
identification, classification, description and nomenclature of living
organisms.
 The word taxonomy is derived from two Greek words (Taxis: arrangement
and Nomos: laws.)
 The word ‘Taxonomy’ was first coined by Augustin-Pyramus de
Candole.
Classification:
Plants arranged into different groups and categories on the basis of
similarities and differences are called classification.
Types of classification:
 Artificial system of classification
 Natural system of classification
 Phylogenetic system of classification
 Modern system of classification
The most famous artificial system of classification is Linnaeus classification
which was proposed by Carolus Linnaeus in Species plantarum.
Taxonomic Hierarchy:
 Species
 Genus
 Family
 Order
 Class
 Division
 Kingdom
Binomial:

Binomial nomenclature was first introduced by Gaspard Bauhin and it
was implemented by Carolus Linnaeus. Scientific name of a species
consists of two words and according to binomial nomenclature, the first
one is called genus name and second one is specific epithet. Example:
Mangifera indica.
Two Kingdom: Carl Linnaeus (1735)
1. Plantae
2. Animalia
Three Kingdom: Ernst Haeckel (1866)
1. Protista
2. Plantae
3. Animalia

Four Kingdom: Copeland (1956)
1. Monera
2. Protista
3. Plantae
4. Animalia
Five Kingdom: R.H. Whittaker (1969)
1. Monera
2. Protista
3. Fungi
4. Plantae
5. Animalia

Six Kingdom: Thomas cavalier smith (1998)
1. Eubacteria
2. Archaebacteria
3. Protista
4. Fungi

5. Plantae
6. Animalia
Seven kingdom: Ruggiero (2015)
1. Eubacteria
2. Archaebacteria
3. Protozoa
4. Chromista
5. Fungi
6. Plantae
7. Animalia
Five Kingdom Classifications:
 R.H.Whittaker, an American taxonomist proposed five kingdom
classification in the year 1969.
 The Kingdoms include
1. Monera,
2. Protista,
3. Fungi,
4. Plantae and
5. Animalia.
 The criteria adopted for the classification include cell structure, thallus
organization, and mode of nutrition, reproduction and phylogenetic
relationship.
Merits:
 The classification is based on the complexity of cell structure and
organization of thallus.
 It is based on the mode of nutrition
 Separation of fungi from plants
 It shows the phylogeny of the organisms
Demerits:
 The kingdom Monera and Protista accommodate both autotrophic and
heterotrophic organisms, cell wall lacking and cell wall bearing organisms

thus making these two groups more heterogeneous Viruses were not
included in the system.

Kingdom
Monera Protista
Cell type: Prokaryotic Cell type : Eukaryotic
Level of Organisms : Unicellular Level of organisms : Unicellular
Cell Wall: Present Cell Wall: Present in some, absent in other
Nutrition: Autotrophic Nutrition: Autotrophic
Motility: Motile or non-motile Motility: Motile or non-motile
Organisms: Archaebacteria
Eubacteria
Cyanobacteria

Organism: Chrysophytes
Dinoflagelates
Euglenoids

Fungi Plantae
Cell Type:Eukaryotic Cell Type: Eukaryotic
Level of Organism: Multicellular& Unicellular Level of Organism: Tissue/Organ
Cell Wall: Present Cell Wall:Present
Nutrition: Heterotrophic Nutrition: Autotrophic
Motility: Non-motile Motility: Mostly-non-motile
Organism: Yeast, Mushrooms & Molds Organism: Algae,Bryophytes, Pteridophytes.

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