The word taxonomy means an arrangement. It is the science for arranging living organisms according to the characteristics they share. The word hierarchy means an arrangement of list of things in an above, below or same level. Taxonomical hierarchy is the part of biological science in which plants, animals, micro organisms etc. are sequentially arranged in descending order during the classification of organism. A Swedish scientist Carolues Linnaeus is called the father of taxonomy because he was the first to observe and categorize the living organism into different category and applied binomial nomenclature for them. He used only five categories first-class, order, genus, species and variety. Then the last one was discarded and three were added- kingdom, division, and phylum.
Taxonomical hierarchy is consist of eight major taxonomic ranks-domain, kingdom, phylum, class, order, family, genus, species. Each rank is consist of subgroups and super groups according to the requirements of taxonomical hierarchy.
Taxon: It is any level of grouping of organisms. e. g. Mammals, roses, reptiles etc.
Species: It is a natural population or group of natural populations of individuals that are genetically distinct and reproductively isolated with similar essential morphological traits. It is also genetically closed system because member do not interbreed with members of other species. It is the basic of taxonomic hierarchy. At times, hybridization occurs between two different species. Interbreeding cannot be applied for delimitation of species in case of prokaryotes’ and some species which lack sexual reproduction. In this case morphological characteristics are used.
Genus: It is an assembly of related species which evolved from some n ancestors, having common characters called correlated characters. Genus are either monotype or polytope.
Family: A group of related genera with certain similar characters.
Order: A group of related families with some common features.
Class: Organisms made of one or more related order. It ends with suffix -phyceae, opsida, ae but in case of animals it differs.
Phylum: All organisms belonging to various classes having a few common characters. In this division the given suffix -phyceae and the subdivision -phytina.
Kingdom: All organisms that shares some common characters. It is the highest rank of taxonomic hierarchy. E.g. kingdom -Animalia, kingdom planta.
Species and genus form together binomial nomenclature. Suppose binomial nomenclature of man is Homo sapiens. Here Homo is genus and sapiens is species. It is written in italics and when hand written it is underlined.
Importance of taxonomical hierarchy are:
1. Categorize living organism easily.
2. Study the development, genetics, cytology, physiology, pathology and evolution of all living organism.
3. Study the characteristics, habits, affinities habitats of different organisms can be done by taxonomic hierarchy.
4. Easy to study the living organism of same species and their connections.
5. Food chains, food webs and biological control cannot be known without taxonomy.
6. All breeding programmes require the knowledge of different traits present in various varieties, subspecies and related species.
1. Who is the father of taxonomic hierarchy?
Answers: Linnaeus is called the father of taxonomic hierarchy.
2. Define classification.
Answers: It is the method of grouping animals according to their similarities and differences.
3. why are scientific name preferred over common names?
Answers: It is used to avoid confusion of names as it occurs in case of common names used for a particular organism in a particular language.