category includes related orders. For example, order Primata comprising monkey, gorilla and gibbon is placed in class Mammalia along with order Carnivora that includes animals like tiger, cat and dog. Class Mammalia has other orders also. .
. Classes comprising animals like fishes, amphibians, reptiles, birds along with mammals constitute the next higher category called Phylum. All these, based on the common features like presence of notochord and dorsal hollow neural system, are included in phylum Chordata. In case of plants, classes with a few similar characters are assigned to a higher category called Division.
. . Kingdom All animals belonging to various phyla are assigned to the highest category called Kingdom Animalia in the classification system of animals. The Kingdom Plantae, on the other hand, is distinct, and comprises all plants from various divisions.
Henceforth, we will refer to these two groups as animal and plant kingdoms. The taxonomic categories from species to kingdom have been shown in ascending order starting with species in Figure . . These are broad categories.
However, taxonomists have also developed sub-categories in this hierarchy to facilitate more sound and scientific placement of various taxa. Look at the hierarchy in Figure . . Can you recall the basis of arrangement?
Say, for example, as we go higher from species to kingdom, the number of common characteristics goes on decreasing. Lower the taxa, more are the characteristics that the members within the taxon share. Higher the category, greater is the difficulty of determining the relationship to other taxa at the same level. Hence, the problem of classification becomes more complex.
Table . indicates the taxonomic categories to which some common organisms like housefly, man, mango and wheat belong. Figure . Taxonomic c a t e g o r i e s s h o w i n g hierarchial arrangement in ascending order Common Biological Family Class Phylum/ Name Name Division Man Homo sapiens Homo Hominidae Primata Mammalia Chordata Housefly Musca Musca Muscidae Diptera Insecta Arthropoda domestica Mango Mangifera Mangifera Anacardiaceae Sapindales Dicotyledonae Angiospermae indica Wheat Triticum Triticum Poaceae Poales Monocotyledonae Angiospermae aestivum T ABLE .
Organisms with