Taxonomy: Meaning of Taxonomy, Nomenclature, Binomial Nomenclature, Ranks Used for Classifying an Organism (For CBSE, ICSE, IAS, NET, NRA 2022)

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Meaning of Taxonomy

  • The science of naming, describing, and classifying organisms.
  • This also includes plants, animals, and microorganisms of the world.
  • It identifies and enumerates the components of biological diversity.
  • In other words, we can say that it is a branch of science dealing with the nomenclature, identification and classification of living organisms including the extinct ones.

Other Taxonomies

  • ACM Computing Classification System
    • For computing devised by the Association for Computing Machinery.
  • Military taxonomy
    • A set of terms for describing various types of military operations and equipment.
  • Legal Taxonomy
    • A subject classification for law devised by Elizabeth Moys.


  • To know the nomenclature of an organism it is important to know all the specifications of the organism.
  • In other words, a nomenclature can be defined as that system which is used to give distinct name to organisms, including plants, animals, microorganisms, and other living things.
  • There are two parts in the name of an organism:
    • Generic name
    • Specific epithet
  • It is the process of describing an organism.

Nomenclature Codes or Codes of Nomenclature

  • The various rulebooks that govern biological taxonomic nomenclature.
  • At present the nomenclature codes govern the naming of:
Nomenclature Codes or Codes of Nomenclature

Binomial Nomenclature

  • Carl Linnaeus (A Swedish botanist, zoologist, and physician) gave this system of nomenclature.
  • For e. g. , the scientific name of an apple is Pyrus malus. Pyrus indicates the β€˜genus’ while malus represents a particular specie.

Rules for the Binomial Taxonomy Nomenclature

  • Biological names are written in Italics with the first word denoting the genus and the second word denoting specific epithet.
  • Genus should start with a capital letter.
  • The specific epithet starts with a small letter.
  • In the abbreviated form, the name of the author is written after the specific epithet.
  • The genus name and species name n to be underlined.
  • Some of the examples are:
    • Homo sapiens (Human Beings)
    • Panthera tigris (Tiger)
    • Mangifera indica (Mango Plant)
    • Canis lupus familiaris (Dog)

Ranks Used for Classifying an Organism

Ranks Used for Classifying an Organism


Modern Humans

Classification of Modern Humans
SpeciesHomo sapiens

Botanical Nomenclature

  • It is the formal, scientific naming of plants.
  • It is distinct from taxonomy.
  • It is governed by the International Code of Nomenclature for algae, fungi, and plants (ICN) . This replaces the International Code of Botanical Nomenclature (ICBN) .

Gene Nomenclature

  • It is the scientific naming of genes, the units of heredity in living organisms.
  • In the 1960՚s, the need to develop formal guidelines for human gene names and symbols was recognized.
  • Gene nomenclature and protein nomenclature are the aspects of the same whole.

International Code of Zoological Nomenclature

  • It is a widely accepted convention in zoology that rules the formal scientific naming of organisms.
  • Informally it is known as the ICZN Code (the International Commission on Zoological Nomenclature) .
  • This system of nomenclature is independent of other systems of nomenclature, for example botanical nomenclature.

Chemical Nomenclature

  • It is a set of rules to generate systematic names for chemical compounds.
  • To ensure that a spoken or written chemical name leaves no ambiguity is the primary function of chemical nomenclature.


  • Principle of binominal nomenclature
  • Principle of priority
  • Principle of coordination
  • Principle of the first reviser
  • Principle of homonymy

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