discuss different systems of classification briefly.

Explanation

Different systems of classification proposed from time to timej have been divided into three basic categories viz., artifical system, natural system and phylogenetic systems.
(1) Artifical system of classification. Artificial system of classification is based on one or a few superficial resemblences. For example, animals are classified as aquatic (water-dwellers), terrestrial (land-dwellers) and aerial (air-dwellers) according to habitat , as carnivores (flesh-eaters) and herbivores (plant eater) according to the mode of feeding , as oviparous (egg-layers) and viviparous (young-producers) according to the mode of breeding, etc. Similarly, plants are classifed as herbs, shrubs and trees on the basis of their habit.
(2) Natural system of classification. Natural system of classification is based on a number of structural and morphological taxonomic charcters. The advocates of natural system of classification are-Michel Adanson, A.L. de Jussieu, A.P. de Candolle, Bentham and Hooker, etc.
(3) phylogenetic system of classification. The classification of organism based on their evolutionary interrelationships is called phylogenetic classification.
Sir Julian juxely (1940) introduced the term new systematics which includes the modern systems of classification based on specified characters. New systematics includes : Morphotaxonomy (based on structural features), cytotaxonomy (based on cytological studies), chemotaxonomy (based on chemical analysis). Numerical taxonomy (involving quantitative assessment of similarities and dfferences), etc.