AIPMT-NEET Biology Aspirants, read out the next AIPMT-NEET Biology Study material/ Notes on Classification. In this we will learn about Classification, taxonomic categories/rank  important for AIPMT-NEET Biology. Free online notes for AIPMT-NEET.

In biology, Classification is the process of grouping living organisms into convenient categories based on some easily observable characters.

• Basic unit of classification is species.
• It involves recognition of species and the placing of species in a system of higher categories (taxa).
• Classification is not a single step process, but involves hierarchy of steps in which each step represents a rank or category. These categories are called as Taxonomic categories and overall arrangement of all categories together constitutes the taxonomic hierarchy.
• Scientific term for category is Taxon (plural: taxa) or we can say taxon is a taxonomic group of any rank.
• Study of all living organisms have led to the development of seven essential taxonomic categories, namely- Kingdom, Phylum or Division (for plants), Class, Order, Family, Genus, Species.
• Species is the lowest category. Group of individual organisms with fundamental similarities are considered as species.
• Genus is a group of closely related species or a group of species that have descended from a common ancestor. It has more common characters comparison to species of other genera.
• Family is a group of related genera with less number of similarities as compared to genus and species.
• Order is a group of related families. Order and other higher taxonomic categories are identified based on the aggregates of characters.
• Class is a group of related orders.
• Classes with few similar characters are placed into a higher category called Phylum. Or phylum is a group of related classes.
• Highest category is Kingdom. Kingdom includes organisms of different phyla. Or related phyla are grouped as a kingdom. Like Kingdom Animalia has animals of different phyla.
  

  Taxonomic ranks hierarchy in ascending order

• As we go higher from species to kingdom, number of common characteristics goes on decreasing.
• Lower the taxa, more are the characteristics that the members within the taxon share.
• Higher the category, greater is the difficulty of determining the relationship to other taxa at the same level.
• Classification of Human: Binomical nomenclature is Homo sapiens.

Kingdom — Animalia

Phylum — Chordata

Class — Mammalia

Order — Primata

Family — Hominidae

Genus —Homo

species — Homo sapiens

• These seven categories are considered essential to define the relationship of a given organism.
• Name of a family is formed by adding -idae to the stem of the name of one of the genera in the group.
• NOTE: Kingdom>Phylum>COF>Genus>Species