Diversity in Living Organism

Hello students before we proceed to our next topic Diversity in living organism, you need to understand certain terms related to that.Here they are:
                                                                   

1.  Classification is the systematical arrangement of different species of living organism according to  similarities and dissimilarities between them.
2. Biodiversity is the variety of life forms that are found in a particular region .
3. Scientific Name ( or Binomial nomenclature) is a unique name given to a species to identify it uniquely and understood worldwide.They are guided by a set of rules by International Code of Biological Nomenclature.Every organism is given two proper name.First is the name of the genus to which the organism belong and second is the Species to which it belong.e.g Homo sapiens
4. Taxonomy can be defined as science of classification.
5. Linnaeus  has been considered as the " Father of Taxonomy".
6. Evolution   was first described by  Charles Darwin  in his book" The Origin of Species" published in 1839.

        

1) Two Kingdom  system of classification:

This system of classification was first proposed by Carolus Linnaeus in 1758.   He classified living organisms   into two group Plant kingdoms and Animal Kingdoms. The difference between    plant and animal is very clear.

                               Later it was observed that some organisms did not fit into these two group.A German Zoologist E.H Haeckel raised a third kingdom called Protista for unicellular organisms. 

                    An American ecologist Robert  H. Whittaker(1959) proposed a fourth kingdom Monera for Bacteria which are prokaryotes and fifth Kingdom  called Fungi  as fungi  lack chlorophyll,  obtain their food by absorption and are eukaryotes,      

2) Five Kingdom System Of Classification :

Whittaker(1959)   has classified  the living organism into five kingdoms.

• Kingdom Monera
• Kingdom Protista
• Kingdom  Fungi
• Kingdom  Plantae
• Kingdom  Animalia

One group of organisms that does not fit neatly into any classification scheme is the Viruses.They are very small particles  containing RNA or DNA covered in protective protein coat.They are like simple chemical when outside living organisms but once they are inside a living organisms they  have control over the mechanism of the cell and start reproducing.They are always harmful.

Taxonomic Hiearchy:

Domain(Archae,Bacteria,Eukarya)
    Kingdom(Plant and Animal)
       Phylum/Division
           Class
                Order
                   Family
                       Genus
                          Species

Species : They are individuals with similar morphological  characteristics.They are able to breed among themselves and produce fertile offspring of their own kind.

Genus: It is a group of species which are related but have less common characters in common.

Family: It is group of related genera which are more similar to each other than genera of  other family.

Order: It is group of similar family.

Class: It is group of similar order.

Phylum: It is group of similar classes.

Kingdom: It  includes a group of organisms that have distinguishing similar characteristics.
                eg. Plant Kingdom and Animal Kingdom.

Domain:  The most general category in taxonomic classification is domain, which is the point of origin for all species .All species belong to one of these domains
                 Bacteria, Archaea, and Eukarya.