Q.Illustrate the taxonomical hierarchy with suitable examples of a plant and an animal.

The taxonomical hierarchy places every organism in a definite series of categories, from species at the bottom up to kingdom at the top, with shared characters decreasing as we go higher. This is best shown by tracing one plant and one animal through the ranks.

• Animal — Man (Homo sapiens): Genus Homo → Family Hominidae → Order Primata → Class Mammalia → Phylum Chordata. Here the largest category shown is a phylum, because animals use 'phylum'.
• Plant — Mango (Mangifera indica): Genus Mangifera → Family Anacardiaceae → Order Sapindales → Class Dicotyledonae → Division Angiospermae. Here the largest category is a division, because plants use 'division' in place of phylum. …

Every organism occupies a definite position in the system of classification. Classification is a hierarchy of steps, each step a rank or taxonomic category, and when the categories are arranged from species up to kingdom they form an ascending order. The guiding principle is the number of shared characters: the lower the taxon, the more its members have in common; as we climb, the shared characters decrease. The best way to see this is to follow a real plant and a real animal up the ladder.

An animal — Man, Homo sapiens:

• Genus — Homo
• Family — Hominidae
• Order — Primata
• Class — Mammalia
• Phylum — Chordata

Man belongs to the species sapiens in the genus Homo. Moving up, Homo falls in the family Hominidae, then the order Primata (which also contains monkeys, gorillas and gibbons), then the class Mammalia (which unites Primata with orders such as Carnivora because they share the mammalian characters), and finally the phylum Chordata (which gathers the classes of fishes, amphibians, reptiles, birds and mammals, united by features such as a notochord and a dorsal hollow neural system).

A plant — Mango, Mangifera indica:

• Genus — Mangifera
• Family — Anacardiaceae
• Order — Sapindales
• Class — Dicotyledonae
• Division — Angiospermae

The mango species indica sits in the genus Mangifera, which belongs to the family Anacardiaceae, the order Sapindales, the class Dicotyledonae and, at the top of what is shown, the division Angiospermae. …