Taxonomic Categories
Taxon is a taxonomic group of any rank that is distinct. Taxon is the unit of classification.
Taxonomic Hierarchy: Taxonomic hierarchy is the framework in which the taxonomic groups called taxa, are arranged in a definite order from higher to lower categories. It is also called as Linnaean hierarchy as it was first proposed by Carolus Linnaeus.
The hierarchy of categories consist of sequence of seven categories, which are arranged in descending order.
Kingdom is the highest category of classification and Species is the lowest category of classification.
The hierarchy indicates the various levels of relationship. Higher the category lesser will be the number of similar characteristics of organisms.
Out of all the various categories only the species have a real existence in nature. Other categories were made for the convenience to study.
Species
A species is the basic unit of classification.
The term species was coined by the scientist John Ray.
Species is a group of closely related organisms which are morphologically similar and can interbreed each other and produce fertile off-springs.
Ex: Mangifera indica (Mango), Panthera leo (Lion).
In these examples indica and leo represents species.
Genus
Group of closely related species which have more similar characters.
Ex: Panthera leo (Lion) and Panthera tigris (Tiger) are two different species, belonging to same genus Panthera.
Family
Family is a group of related genera. The related genera have less similarities as compared to genus and species.
Ex: Genera Panthera (tiger, lion) and Genera Felis(cats) have many similar qualities and are placed in the family Felidae.
Genera Solanum and Lycopercicum have many common qualities and placed in family Solanaceae.
Order
The related families are grouped together in a category called order.
Ex: Order Cornivora includes, Family Felidae(Cats) and family Canidae(dogs).
In Plants, Order Polymoniales includes, Family Solanaceae and Convolvulaceae.
Class
A class consists of organisms of related orders.
Ex: Carnivora and Primata are included in class Mammals.
Phylum
The related classes are placed under same phylum.
Ex: Phylum Chordata includes Pisces, Amphibia, Reptilia, Aves and Mammalia.
In Plants, the related classes are grouped together in a higher category called Division.
Kingdom
Kingdom is the highest taxonomic category. A kingdom includes all the organisms that have some distinct characters.
Ex: All animals are placed in Kingdom Animalia.
Similarly, all plants are placed in Kingdom Plantae.
Organisms with their Taxonomic Categories
Taxonomical aids
Taxonomic studies of various species of plants, animals and other organisms are useful in agriculture, public health and environmental biology.
These studies require correct classification and identification of organisms.
Identification of the organisms requires intensive laboratory and field studies and collection.
Collection of specimens is the prime source of taxonomic studies.
All those collections of actual live specimens, which help in the identification are called taxonomical aids.
Taxonomic aids include,
(i) Herbarium
(ii) Botanical Gardens
(iii) Zoological Parks
(iv) Museums
(v) Keys
Herbarium
A herbarium is a storehouse of collected plant specimens, that are dried, pressed and preserved on sheets.
The sheets are organised and arranged according to a universally accepted system of classification.
Steps involved in the preparation of Herbarium
a) Collection of the specimens.
b) The collected specimens are pressed and dried to remove the moisture content.
c) Pasting of the dried specimens on the herbarium sheets of standard size i.e. 23*41cm.
d) The pasted specimens are sprayed with fungicides to avoid fungal growth.
e) A label is pasted on each herbarium sheet that contain information like, Locality of collection, Name of the collector, Date and time of collection, Common name, Scientific Name, Family name and few key points about the specimen.
Some important herbaria of the world
First Herbarium was founded in the University of Padua, Italy.
Herbarium of Royal Botanical Gardens, Kew. Great Britain.
Herbarium of Indian Botanical Gardens, Kolkata.
Herbarium of Botanical Survey of India, Pune.
Botanical Gardens
Botanical gardens are large sized area that have collections of living plants, maintained for identification and classification.
Botanical garden is an educational institute that is systematically organized and beautiful landscape, with the collection of varieties of trees, ornamental plants, and medicinal plants.
A botanical garden generally has a herbarium, library, art and photographic study center, lecture hall and nurseries.
The famous botanical gardens
Royal Botanical garden Kew.
Indian Botanical Garden Kolkata.
National Botanical Garden Lucknow.
Zoological Parks
Zoological Parks are the places where, wild animals are protected under conditions similar to natural habitat under human care.
The parks are the site to, breed animals under captivity to avoid extinction.
Zoological parks are the recreational centers and also help us to know about wild animals, their food habit, behavior etc.
Some famous zoological parks
Gir national Park, Gujarat.
Bannerughatta National Park Bangalore.
Corbett National Park Uttarakhand.
Museum
A museum has collections of preserved plant and animal specimens, for the study and reference.
Biological museums are usually set up in the schools and colleges and other biological institutions.
The specimens have been correctly identified, labelled, stored and exhibited to public.
The plant and animal specimens are preserved in chemical solutions or as dry specimens.
Larger animals are usually preserved as stuffed specimens.
Keys
Key is a tool by which plants and animals can be identified, based on similarities and differences.
The keys are based on contrasting characters called couplet.
Each couplet actually represents, a choice made between two contrasting characters, leading to selection of one.
Each statement in key is called lead.
Keys are of two types
(i) Indented keys: which provides a sequence of choices between two or more statements of characters of species
(ii) Bracketed keys: where pairs of contrasting characters are used for identification.
Other taxonomical aids for recording descriptions
Flora: Flora contains the actual information about habitat and distribution of plants. It provides index to the plant species found in a particular area.
Manuals: These provide information for identification of species found in an area.
Monographs: Monographs are the books that contain information on any one taxon.
Taxon is a taxonomic group of any rank that is distinct. Taxon is the unit of classification.
Taxonomic Hierarchy: Taxonomic hierarchy is the framework in which the taxonomic groups called taxa, are arranged in a definite order from higher to lower categories. It is also called as Linnaean hierarchy as it was first proposed by Carolus Linnaeus.
The hierarchy of categories consist of sequence of seven categories, which are arranged in descending order.
Kingdom is the highest category of classification and Species is the lowest category of classification.
The hierarchy indicates the various levels of relationship. Higher the category lesser will be the number of similar characteristics of organisms.
Out of all the various categories only the species have a real existence in nature. Other categories were made for the convenience to study.
Species
A species is the basic unit of classification.
The term species was coined by the scientist John Ray.
Species is a group of closely related organisms which are morphologically similar and can interbreed each other and produce fertile off-springs.
Ex: Mangifera indica (Mango), Panthera leo (Lion).
In these examples indica and leo represents species.
Genus
Group of closely related species which have more similar characters.
Ex: Panthera leo (Lion) and Panthera tigris (Tiger) are two different species, belonging to same genus Panthera.
Family
Family is a group of related genera. The related genera have less similarities as compared to genus and species.
Ex: Genera Panthera (tiger, lion) and Genera Felis(cats) have many similar qualities and are placed in the family Felidae.
Genera Solanum and Lycopercicum have many common qualities and placed in family Solanaceae.
Order
The related families are grouped together in a category called order.
Ex: Order Cornivora includes, Family Felidae(Cats) and family Canidae(dogs).
In Plants, Order Polymoniales includes, Family Solanaceae and Convolvulaceae.
Class
A class consists of organisms of related orders.
Ex: Carnivora and Primata are included in class Mammals.
Phylum
The related classes are placed under same phylum.
Ex: Phylum Chordata includes Pisces, Amphibia, Reptilia, Aves and Mammalia.
In Plants, the related classes are grouped together in a higher category called Division.
Kingdom
Kingdom is the highest taxonomic category. A kingdom includes all the organisms that have some distinct characters.
Ex: All animals are placed in Kingdom Animalia.
Similarly, all plants are placed in Kingdom Plantae.
Organisms with their Taxonomic Categories
Taxonomic studies of various species of plants, animals and other organisms are useful in agriculture, public health and environmental biology.
These studies require correct classification and identification of organisms.
Identification of the organisms requires intensive laboratory and field studies and collection.
Collection of specimens is the prime source of taxonomic studies.
All those collections of actual live specimens, which help in the identification are called taxonomical aids.
Taxonomic aids include,
(i) Herbarium
(ii) Botanical Gardens
(iii) Zoological Parks
(iv) Museums
(v) Keys
Herbarium
A herbarium is a storehouse of collected plant specimens, that are dried, pressed and preserved on sheets.
The sheets are organised and arranged according to a universally accepted system of classification.
Steps involved in the preparation of Herbarium
a) Collection of the specimens.
b) The collected specimens are pressed and dried to remove the moisture content.
c) Pasting of the dried specimens on the herbarium sheets of standard size i.e. 23*41cm.
d) The pasted specimens are sprayed with fungicides to avoid fungal growth.
e) A label is pasted on each herbarium sheet that contain information like, Locality of collection, Name of the collector, Date and time of collection, Common name, Scientific Name, Family name and few key points about the specimen.
Some important herbaria of the world
First Herbarium was founded in the University of Padua, Italy.
Herbarium of Royal Botanical Gardens, Kew. Great Britain.
Herbarium of Indian Botanical Gardens, Kolkata.
Herbarium of Botanical Survey of India, Pune.
Botanical Gardens
Botanical gardens are large sized area that have collections of living plants, maintained for identification and classification.
Botanical garden is an educational institute that is systematically organized and beautiful landscape, with the collection of varieties of trees, ornamental plants, and medicinal plants.
A botanical garden generally has a herbarium, library, art and photographic study center, lecture hall and nurseries.
The famous botanical gardens
Royal Botanical garden Kew.
Indian Botanical Garden Kolkata.
National Botanical Garden Lucknow.
Zoological Parks
Zoological Parks are the places where, wild animals are protected under conditions similar to natural habitat under human care.
The parks are the site to, breed animals under captivity to avoid extinction.
Zoological parks are the recreational centers and also help us to know about wild animals, their food habit, behavior etc.
Some famous zoological parks
Gir national Park, Gujarat.
Bannerughatta National Park Bangalore.
Corbett National Park Uttarakhand.
Museum
A museum has collections of preserved plant and animal specimens, for the study and reference.
Biological museums are usually set up in the schools and colleges and other biological institutions.
The specimens have been correctly identified, labelled, stored and exhibited to public.
The plant and animal specimens are preserved in chemical solutions or as dry specimens.
Larger animals are usually preserved as stuffed specimens.
Keys
Key is a tool by which plants and animals can be identified, based on similarities and differences.
The keys are based on contrasting characters called couplet.
Each couplet actually represents, a choice made between two contrasting characters, leading to selection of one.
Each statement in key is called lead.
Keys are of two types
(i) Indented keys: which provides a sequence of choices between two or more statements of characters of species
(ii) Bracketed keys: where pairs of contrasting characters are used for identification.
Other taxonomical aids for recording descriptions
Flora: Flora contains the actual information about habitat and distribution of plants. It provides index to the plant species found in a particular area.
Manuals: These provide information for identification of species found in an area.
Monographs: Monographs are the books that contain information on any one taxon.
1 Comments
Well done sir. It is really helpful to students and lecturers.
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