 |
| Taxonomic Hierarchy |
Taxonomy is a process of classification by which all living organisms can be classified into different taxa. So in Taxonomy, there are so many taxon (pl.: taxa) are existed which are represents by ‘category‘. Each ‘category’ referred to as a unit of classification.
Taxonomic Categories
Taxonomic Categories are distinct biological entities. Each category represents a rank, commonly termed as taxon. Each taxon represents a unit of classification. In taxonomic studies, all known organisms have led to common categories such as Kingdom, Phylum or Division, Class, Order, Family, Genus & Species.
 |
| Taxonomic Categories |
Taxonomic Hierarchy
As Category further denotes rank for a perticuler taxon, categories are systematically arranged at each level of taxon in a hierarchical order for all known organisms and constitute Taxonomic Hierarchy.
In taxonomic hierarchy, the hierarchial arrangement of taxonomic categories are ascending in order, i.e, from Species to Kingdom.
Species
In taxonomic studies, a group of organisms with fundamental similarities termed as Species. Two closely related species can be distinguished by distinct morphological differences. In Biological Nomenclature, the second word indicate ‘Species’ of a indivisual organism. For example, Scientific name of mango is Mangifera indica. Here ‘indica‘ is the species of mango.
Species is genetically closed fundamental smallest unit of Classification.
Genus
Aggregation of closely related species constitute a comparatively higher taxonomical category called Genus. Each genus may have one or more than one specific epithets representing different organisms. In plant, ‘Solanum‘ is a genus which include both the species ‘tuberosum‘ (Potato) and ‘lycopersicum’ (Tomato). In animal ‘Panthera‘ is common genus of the species ‘leo‘ (Lion), ‘pardus’ (Lepord) and ‘tigris’ (Tiger).
Genus has more characters in common in comparison to species of other genera.
 |
| Common character comparison |
Family
A group of related genera with less number of similarities as compared to genus and species is represent a category, Family. ‘Solanaceae’ is a plant family which include many genus like ‘Solanum‘, ‘Petunia’, ‘Datura’ etc.
For plant species, Families are characterised on the basis of vegetative as well as reproductive features.
Order
Order is the assemblage of families exhibiting a few similar characters which are less in number as compared to different genera included in a family. On the basis of floral characters, Convolvulaceae and Solanaceae are included in the order Polymoniales.
Class
Class, a higher category, includes related orders. Primata is an order including Monkey, Gorilla & Gibbon. Carnivora is an another order comprising Tiger, Cat & Dog. These two order, Primata & Carnivora belong to same class Mammalia. So monkey, gorilla, gibbon, tiger, cat & dog all are Mammals.
Phylum
Phylum, the higher category of class based on common features. For example, Phylum Chordata is based on presence of notochord.
In case of plants, ‘Division’ term is used instead of phylum. ‘Arthopoda’ is a phylum as it represent an animal category while ‘Angiosperm’ is a division of plant kingdom.
Kingdom
 |
| basis of various taxa |
- In Taxonomic hierarchy, Kingdom is the highest category while Species is the lowest category.
- Kingdom, Phylum or Division, Class, Order, Family, Genus & Species — these seven categories are broad category. However, there are so many sub-categories are developed by taxonomists to be placed more scientifically of various taxa.
- If we go higher from species to kingdom in the taxonomic hierarchy, number of common characteristics goes to decreasing.
Thanks for reading…….