Nomenclature : Naming & Hierarchy

Nomenclature is the determination of the scientific name or correct name to all organisms so that they are easily distinguished.

Nomenclature

Nomenclature is the determination of the scientific name or correct name to all organisms so that they are easily distinguished. Mainly there are two types of nomenclature. They are as follow;

• Common naming system
• Scientific naming system( Binomial nomenclature)

Common naming system:

Common names are not based upon the characteristics and classification. They do not give information about the relationship between genus and family.The common names create three main defects.

• They may be quite indefinite.
• They are restricted to the people of one language or even one part of the country.
• They are not regulated by any constituted authority.

Binomial nomenclature:

Binomial nomenclature is a system of naming organisms in two words which is also called scientific naming. This system was first time used by scientist CarolusLinneanus in 1753. There areInternational Code of Botanical Nomenclature (ICBN), International Code of Zoological Nomenclature (ICZN) and bacteriological nomenclature to regulate this binomial system of nomenclature.

Rules of Binomial Nomenclature:

• For every organism, there are two words given in which the first word is the generic name and the second word is the specific name or specific epithet.
• The scientific name is always followed by a generic name.
• The initial letter of a generic name is capital and the initial letter of a specific name is small.
• The scientific name, if it is in the handwritten form then we should underline it and if it is in printed form it should be in italics.
• Name of the scientist who has derived the name can be abbreviated at the end.
• Scientific name should be in the latin language.
• If two scientist is working and giving the scientific name for the same organism, the valid scientific name must be given for that of an earlier publisher.
• The specimen on the basis of which scientific name was given must be preserved as a type specimen.
• If some species has varieties then three words are given in which last word is variety name.Eg: Brassica aleraceae capitata

Advantages of binomial nomenclature:

• The scientific name of an organism is universal and it is recognized throughout the world.
• The nomenclature shows the evolutionary relationships among various species under the same genus.
• The scientific names make the communication easier in the different part of the world.
• It helps in recognition or identification of a newly discovered organism.
• It indicates a relationship between the different varieties of species.

Taxonomy Hierarchy

Kingdom: Animalia

Phylum: Chordata

Class: Mammalia

Order: Primates

Family: Hominidae

Genus: Homo

Species: Sapiens

Various categories used in classification are arranged in a ranking system one above another which is called taxonomy hierarchy. Taxonomy was first time used by scientist Carolus Linneanus. There are seven categories used in classification namely kingdom, phylum, division, class, order, family, genus and species. We can add super and sub-categories above and below each category.

Categories of Classification:

There are seven main categories used in classification:

Kingdom:

Kingdom is the highest taxonomic category in which all the organisms are included in the five-kingdom i.e. monera, protista, fungi, plantae and animalia.

Phylum:

The phylum includes the classes of different organisms that have some characteristics in common.

Class:

It is a group of similar order.

Order:

Order is a group of similar family.

Family:

Family is defined as a group of similar genera which show similar character in their floral parts.

Genus:

Genus is a group of similar species which show similar characters in their morphology.

Species:

Species is a group of individuals or population which resemble one another in their essential morphological and physiological characters and they can freely interbreed to produce their own kind.

A taxon is a group of organisms having a certain distinct character from those of other groups.

Categories are the various grouping levels used in classification.