Question

How many obligate categories constitute hierarchy of categories?

Answer 1

Hint: By Linnaeus, they are often referred to as the hierarchy of Linnaea. It is characterized from kingdom to species and vice versa as a sequence of categories in a decreasing or increasing order. Taxonomic hierarchy in increasing or decreasing order refers to the sequence of categories.

Complete answer:
There are 7 obligate categories included in hierarchical classification The highest rank is the kingdom, followed by division, class, order, family, genus and species. The lower rank in the hierarchy is the species. The hierarchy has two compulsory and intermediate classifications. Obligatory means they are strictly followed and, as said above, vary from kingdom to species. Intermediate is not strictly followed and is included in the mandatory list, such as sub-division, super-family, super-class, sub-order, subspecies, etc.
Species: A species group that is identical in form, shape and reproductive characteristics in order to produce a fertile relative. When a hybrid is made, some siblings may be sterile.
Genus: It is defined as a group of species of similar origin. But having several organisms is not mandatory. There is only one species classified as mono typical in certain genera. It is referred to as polytypic if there is more than one species.
Family: described as a group of similar genera. It can be distinguished by reproductive and vegetative features from genera.
Order: Order constitutes one or more related families. The Felidae family is part of the Carnivora order.
Class: A class is rendered by one or more of an order. All mammals, bats, rats, kangaroos, whales, great apes and man, are included in the class mammalia.
Phylum: It is a term used for species, while for plants the classification of synonyms is used. It is a set of classes which are identical. Phylum chordata of mammals, along with birds, reptiles and amphibians, have class mammalia.
Kingdom: The highest group with the most taxonomy. All species are classified in the kingdom of Animalia, for example. The classification unit that denotes the grouping of species based on measurable characteristics is known as a taxon.

Note:
Taxonomic aids apply to the various approaches used to recognize and classify species. Organism detection is a repetitive process. Keys are used for taxonomic key recognition. Kingdom is the highest rank and species is the lowest rank in the hierarchy.