Test: Taxonomic Categories (NCERT) - NEET MCQ

• Classification is the arrangement of organisms into convenient categories or groups on the basis of their similarities and differences in certain easily observable but fundamental characters.
• A hierarchy of categories is raised keeping in mind the affinities or relationships of various groups. The various taxonomic categories represent distinct biological entities and not merely morphological aggregates.
• The various categories are kingdom, phylum (or division in plants), class, order, family, genus and species.

• Hierarchy of categories is the classification of organisms in a definite sequence of categories (taxonomic categories) in a descending order starting from kingdom and reaching upto species or an ascending order from species to kingdom.
• The number of similar characters of categories decreases from lowest rank (species) to highest rank (kingdom).
• The taxonomic hierarchy includes seven obligate categories kingdom, division or phylum, class, order, family, genus and species.

Fig: Taxonomical hierarchy showing arrangement in ascending order

From the given representation of taxonomical hierarchy, it is clear that family is interpolated between order and genus. Some subcategories like tribe, subfamily, subspecies are also used whenever required.

The correct hierarchy of classification of various taxons in descending order is given by :
Kingdom → Phylum → Class → Order → Family → Genus → Species
The kingdom is the highest level of classification while species being the most specific.
Since Class occupies the highest level amount all options, it has most generalized characters and organisms share least similar characters at this level.
So, the correct option is 'Class'.

Study of different kinds of organisms, their diversity and the evolutionary relationships among them is called systematics. Approximately 8.7 million species of different living organisms have been identified since the application of this system and even today about 50 new organisms are being discovered on a daily basis.

Species occupies a key position in classification and it represents the lowest taxonomic category. A species is the basic unit of the biological classification of the organisms. According to the definition of the biological species, it is a group of organisms living in a particular area at a particular time and are capable of interbreeding.

As per the definition given by Ernst Mayr in 1964:
"A species is a group of actually or potentially inbreeding populations that are reproductively isolated from other such groups.''
A species may have subgroups, called subspecies or varieties, showing certain distinct features of their own.

• Family is a taxonomic category which contains one or more related genera. All the genera of a family have some common features and they are separable from genera of a related family by important characteristic differences.
• The family Solanaceae includes a number of genera like Solanum, Petunia, Atropa, etc. due to certain similarities.
• They are distinct from the genera of the related family Convolvulaceae such as Convolvulus, Ipomoea.
• In the same way, the family Felidae which includes the genus Panthera of lion, tiger, leopard and genus Felis of cats is distinctly separated from the family Canidae which includes dogs and foxes.

• Unlike asexual reproduction, sexual reproduction involves two parent species.
• Sexual reproduction takes place only when both the parent organisms belong to the same species.

Birds or Aves is the taxonomic class all flying chordates with four-chambered heart and feathers on their body are placed in.

Taxon is a unit of classification which may represent any level of grouping of organisms based on certain easily observable common characteristics.

May (1964) has defined taxon to be a taxonomic group of any rank that is sufficiently distinct to be worthy of being assigned to a definite category.

• Panthera refers to the genus to which lion, tiger and leopard belong to.
• Canidae refers to the family to which wolves, dog, jackals and foxes etc. belong to.
• Felidae is the family to which lion, tiger, leopard and cats etc. belong to.
• Mammalia is a class of animals which includes all the milk-feeding animals like dogs, cats, humans, bats etc.

• The name of a plant order ends with -ales.

  Here's a brief explanation of each suffix:

• -ae: Typically used in the names of families or subfamilies in zoological nomenclature (e.g., "Felidae" for the cat family).
• -ales: Used for the names of plant orders (e.g., "Rosales").
• -idae: Commonly used for the names of animal families in zoology (e.g., "Canidae" for the dog family).
• -aceae: Used for the names of plant families (e.g., "Rosaceae" for the rose family).

• Animal kingdom is divided into Vertebrata and Non-vertebrata based on the presence or absence of vertebral column.
• Plants are divided into Cryptogams and Spermatophytes.

• Humans, ape and monkey belong to the order Primata whereas cats, lion, dogs, tigers belong to the order called Carnivora.
• But all of the above animals belong to the class of Mammalia.

• Bats belong to the order of Chiroptera, class of Mammalia, clade of Scrotifera and phylum of Chordate.
• Human beings also belong to the class of mammalian.

Answer: C. Species
Solution: The species is the smallest and most basic unit of classification in the taxonomic hierarchy. It comprises a group of individuals that are similar in essential morphological characteristics and can interbreed to produce fertile offspring.