Theory:

The living organisms should be classified into smaller groups as they are large in number. Hence all living organisms are classified based on their differences, characteristics and similarities.
What is classification?
  
The method of arranging the organisms into groups based on their characteristics in known as classification
Why is classification mandatory?
  • Classification of things makes it easy for us to know and understand the similarities and differences.
  • The things that have similar characters are generally classified into the same group, and these things will have at least one similar characteristic.
  • The things that have different characteristics are classified into different groups and have at least one different characteristic.
  • With the help of classification, we can understand in a better way about living and non-living things. For example, if a newly discovered organism is classified, we can clearly understand how it relates to the other.
What is the need for classification?
  • Classification helps in identifying an organism correctly.
  • It helps to know the origin and evolution of an organism.
  • Through classification can establish the relationship between different organisms.
  • The information can be established about the living organisms in the different geographical regions.
  • It provides information about living things in different geographical regions.
  • Classification helps in understanding the evolution of complex organisms from simpler ones.
The scientists have discovered and classified more than 2 million organisms on earth ranging from tiny bacteria to the largest blue whales. Based on its evolutionary relationship with the other group of organisms each and every organism have been classified.
The hierarchy of organisms can be classified as follows:
The system of arranging the taxonomic categories in a descending order based on their relationships with other group of organism is called hierarchy of categories.
The hierarchy of categories is a system that was introduced by Linnaeus and is called Linnaean
hierarchy. There are seven main categories of hierarchies namely, Kingdom, Phylum, Class, Order, Family, Genus and Species.
 
Screenshot_11.jpg
Hierarchy of classification
Important!
Species is the basic unit of classification.
Reference:
https://commons.wikimedia.org/wiki/File:Biological_classification_L_Pengo_vflip.sr.jpg#/media/File:Biological_classification_L_Pengo_vflip.svg