The Jay's Biology

TANONOMIC CATEGORIES Taxonomic Category is a unit of grouping of any level used in taxonomy or classification of organisms. Usually there are seven obligate and few intermediate categories used in taxonomy. Hierarchy of categories It is a system in which members of a type are organized in rank on above the other. Hierarchy of categories or taxonomic hierarchy is the system of arrangement of taxonomic categories in a descending order depending upon their relative dimensions. It was introduced by Linnaeus and is therefore also called Linnaean hierarchy or taxonomic hierarchy . Linnaeus proposed five categories- class, order, genus, species, and variety. The latter worker deleted the category of variety and added the categories of kingdom, phylum/division, and family   The taxonomic categories which are always used in hierarchical classification of organisms are called obligate categories . They are seven in number . Obligate categories in descending order are

IDENTIFICATION It is the process of finding the correct place in a system of classification and finding out the correct name of the organism. It is just like locating a title in the library on the basis of knowledge of its subject title and name of the author. Identification is carried out with the help of keys. CLASSIFICATION Biological classification is the scientific arrangement in a hierarchical series of groups and sub groups on the basis of similarities and dissimilarities in their characters so as to bring out their relationship. It is just like arranging the books in a library subject wise, title wise and author wise in a proper sequence. Need of classification 1.       It is not possible to identify an organism without any system of classification. 2.       New organisms are discovered every year therefore it is required to have system of classification to find out correct resemblance. 3.       Study of fossils requires a proper system of c

TAXONOMY It is the study of rules, principle and practice of classification, identification and nomenclature of an organism. The term was coined by de candolle . Carolus Linnaeus   is known as the Father of taxonomy . Taxonomic studies are based on the comparative study of morphology, cytology, embryology, molecular biology, etc. This gives the information about the similarities, dissimilarities and evolutionary relationship. PHYLOGENY It is the evolutionary history or lineage of one or more groups of organisms. It is based on the study of fossils, comparative anatomy and other fields of study. SYSTEMATIC The science which deals with identification, description, classification and nomenclature based on unique properties of every species and group of species at every level of classification. The term was coined by C.Linnaeus. It is often interchangeable with taxonomy . PROCESSES BASIC TO TAXANOMY There are four basic processes of taxonomy- char