Question: Define and understand the following terms:
- Phylum: – In biological classification, a phylum is a classification level or taxonomic rank above class and below kingdom. The term phylum is used for animals. A phylum is formed of one or more related classes of animals. For example, the Phylum Chordata of animals contains not only the class Mammalia but also Aves (birds), Reptilia (reptiles), Amphibia (amphibians), etc. In the plant kingdom, the term Division is used in place of Phylum.
- Class: – In biological classification, class is a taxonomic group or taxonomic rank below Phylum and above order, consisting of one or more related orders. For example, the Class Dicotyledoneae of flowering plants contains all dicots (having two cotyledons), which are grouped into several orders (Example: Rosales, Sapindales, Ranales, etc.). Similarly, the class, Mammalia, includes many orders (Example: Rodentia, Chiroptera, Primates, Carnivora, etc.).
- Family: – In biological classification, a family is a taxonomic group containing one or more related genera, especially sharing a common attribute. They can be distinguished from genera of a related family by significant and distinctive differences in both vegetative and reproductive features. For example, the family Felidae includes several genera like Felis (Cats) and Panthera (Leopard). The members of the family Felidae are quite distinct from members of the family Canidae (dogs, foxes, wolves). Similarly, Solanaceae includes several genera like Datura, Solanum, Petunia, and Nicotiana. They can be distinguished from the genera of the related family Convolvulaceae (Convolvulus, Ipomoea).
- Order: – In biological classification, the order is a taxonomic group containing one or more related families. For example, the plant Family Solanaceae is placed in the Order Polemoniales along with four other related families, i.e., Convolvulaceae, Boraginaceae, Hydrophyllaceae, and Polemoniaceae. Similarly, the animal families Felidae, Canidae, Hyaenidae (hyaenas), and Ursidae (bears) are all included under the Order Carnivora.
- Genus: – In biological classification, a genus is a taxonomic group including closely related species which resemble one another in certain correlated characteristics. All species of the genus are thought to have originated from a common ancestor. A genus may have a single living species, for example, genus Homo and its species is Homo sapiens-the modern man. The genus Felis has many species, for example, Felis Domestica (common cat), Felis chaus (jungle cat), etc.
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