Taxonomic Hierarchy In Biological Classification MCQ - Practice Questions with Answers

• A taxon is defined as a unit in classification or taxonomic group of any rank. For example, conifers is a taxon and order is a taxonomic category for it. 
• Dicotyledonae is a taxon and class is its taxonomic category. 

Taxonomic Hierarchy (Taxonomic categories)

• It refers to the classification of organisms in a hierarchical manner in the definite sequence of categories starting from the kingdom and going to species. 
• These specific categories are called taxonomic categories. This hierarchy is also called Linnaeus hierarchy.
• The number of similar characters increases when we go from kingdom to species. 
• There are a total of seven taxonomic categories.

Kingdom- It is the highest taxonomic category. All the plants are included in the kingdom Plantae. The members included in one kingdom share fundamental characters. 

Phylum or Division- It is the category lower than the kingdom. The phylum is for animals while division is for plants. A phylum will have different classes. Phylum Chordata includes a variety of organisms classified into classes Mammalia, Aves, Reptilia etc.

Class- It is the category lower to phylum. It consists of related orders. Class Dicotyledonae consists of orders like Rosales, Passifloraceae, Polemoniales, Sapindales etc. 

Order- This category includes related families. Solanaceae, Convolvulaceae, Boraginaceae, Hydrophyllaceae and Polemoniaceae are included in order Polemoniales. 

Family- This taxonomic category contains related genera. Family Solanaceae contains genera like Solanum, Petunia, Nicotiana etc.  

Genus- A genus is an aggregate of related species that are similar to each other in many correlated characters. Genus can be monotypic i.e. having one species or polytypic i.e. having many species. Genus Solanum possesses species like Solanum nigrum, Solanum tuberosum (potato), Solanum melongena (brinjal) etc. 

Species- This the smallest unit of classification. It includes organisms that are similar in most of their characteristics and that can interbreed among themselves. The second name in a scientific name is species name. E.g. indica in Mangifera indica, sapiens in Homo sapiens represent species. The term species was coined by John Ray. 

Tip -Tautonyms 
The scientific names in which the generic name and specific names are the same. E.g. Malus malus, Bison bison etc.

Tip- Homonyms
When the same name is used for two different species, they are termed homonyms. The one published earlier is validated.