DEFINITION
Advantages of classification
Classification makes the study of such a large number of living organism easy.
It presents before us the vast variety of life at a glance.
It helps us in understanding the relationships among the organisms.
It helps to give us an idea of evolution.
It serves as a basis for several allied branches of biology.
DEFINITION
Introduction to systematics
The kind of cells that living organisms are made up of is a more basic characteristics for classifying organisms, than on the basis of their habitat.
DEFINITION
Systematics
Systematics is the branch of biology that deals with the diversity of organisms and their comparative and evolutionary relationships based on comparative anatomy, comparative biochemistry, comparative physiology and comparative ecology.
DEFINITION
Nomenclature of organisms
The scientific naming of an organism is called nomenclature.
The organisms are given scientific name by the International Code of Botanical Nomenclature (ICBN) and the International Code of Zoological Nomenclature (ICZN).
DEFINITION
Binomial nomenclature
Introduced by Carolus Linnaeus is the method of naming an organism with the genus name first and species name later.
For example, the scientific name of a ladybug found in the United States is Harmonia axyridis. The first part of a scientific name, like Harmonia, is called the genus. The second part of a scientific name, axyridis in this example, is the species.
DEFINITION
Taxonomic Categories
Carolus von Linnaeus created a hierarchical classification system using seven taxonomic categories.
Kingdom - Topmost taxonomic category.
Phylum - Term used for animals while its synonym division is used for plants.
Class - One or more than one order makes a class.
Order - One or more than one similar families constitute order.
Family - Collection of similar genera.
Genus - Group of similar species.
Species - Group of population which is similar in form, shape and reproductive features so that fertile sibling can be produced.
DEFINITION
Taxonomic category- Species
A group of individuals in which the individuals can interbreed among themselves is called as species. Members of a species have a large number of similar characters.
For example, all the tigers are called as Panthera tigris.
DEFINITION
Taxonomic category- Genus
A group of closely related species is called as genus.
For example, lion (Panthera leo), leopard (Panthera pardus) and tiger (Panthera tigris) are members of the genus Panthera.
DEFINITION
Taxonomic category- Family
A group of closely related genera is known as family.
For example, potato and chili belong the family Solanaceae.
DEFINITION
Taxonomic category- Order
A group of closely related families is known as order.
For example, Convolvulaceae and Solanaceae are plant families which belong to the order Polymoniales.
DEFINITION
Taxonomic category- Class
The group of closely related orders is called as class.
For example, orders Primata and Carnivora belong to the class Mammalia.
DEFINITION
Taxonomic category- Phylum
A group of closely related classes is called Phylum.
For example, pisces, amphibia, reptilia, aves and mammalia belong to the Phylum Chordata.
DEFINITION
Taxonomic category- Kingdom
The group of all the related phyla is called the Kingdom.
For example, all autotrophic organisms which are eukaryotic and contain chloroplast are kept under the plant kingdom.
Similarly, all heterotrophic organisms which are eukaryotic and lack a cell wall are kept under animal kingdom.
DEFINITION
Differnce between taxon and category
Taxon
Category
Taxon is the representation of any level of the taxonomic category. It is constructed by individual biological objects.
Species includes all the organisms that are similar to breed and produce fertile offspring. Species is one taxonomic category and is an abstract term.
Taxon can be of monophyletic or polyphyletic generation.
Species is always monophyletic.
DEFINITION
Taxonomic aids
Taxonomical aids are the collections of samples or preserved organisms which help in extensive research for the identification of various taxonomical hierarchy.
DEFINITION
Herbarium
A herbarium is a reference collection consisting of carefully selected and dried plants attached to paper sheets of a standard size and field in a systematic way so that they may be easily retrieved for examination.
DEFINITION
Zoological park
Zoological park is a place where various living animals are kept within enclosures, displayed to public and may be used for study.
For example, Alipore zoological gardens, Kolkata.
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