Taxonomy hierarchy And Systematics Class 11 Notes Biology Chapter 1

In the section you will get Class 11 Notes Biology Chapter 2 of Taxonomy Hierarchy And Systematics.


Plants and animals are known by different names in different languages ​​in different parts of the world. Such names are native languages. This causes communication problems in different parts of the world.

For the scientific study of organisms, a specific name is given to a specific organism that is universally recognized. This process of naming organisms is called nomenclature or biological nomenclature.

Prior to naming an organism it was properly researched and assigned to a group. This process is called identification.

For the purpose of nomenclature, biologists have developed guidelines that can be followed by people around the world.

  • The International Code of Botanical Nomenclature (ICBN) sets out the principles for giving botanical names to plants.
  • Similarly, recommendations made by the “International Code of Zoological Nomenclature”  (ICZN) are used to name animals.

Scientists confirm that the name given to an organism has not previously been used for any other organism.

Taxonomy Hierarchy And Systematics Class 11 Notes Biology Chapter 1 image


As a structured rule, the scientific name given to an organism has two distinct parts-

The first part is the genus (generic name) the second part is the species  (specific name).

This method of naming two fields is called binomial nomenclature and was proposed by the Swedish naturalist Carolus Linnaeus (1707–1778).

For his contribution in the field of nomenclature and taxonomy, Linnaeus was referred to as the father of classification.

Below are some important rules of binomial nomenclature-

1. Each biological name has two parts: the first part is the genus or generic name and the second is the species or specific name.

For example, the zoological name of the tiger is Panthera tigris and the botanical name of the tree is Ficus bengalensis.

2. The first letters of the race are in the block capital, while the species is smaller and the same name is written in italic.

3. There is a space between common and specific names.

4. When handwritten, the two names are underlined separately, but in printed material, the words are written in italics.

5. Scientific names are derived from Latin or Latin, even if they originate from other languages.

6. The name of the author who first describes the species is mentioned after the year of its description, followed by the particular name. The author’s name may be abbreviated, e.g. Linnaeus as Lin… Thus the scientific name of the man is Homo sapiens Linn., 1758.


Taxonomic Definition:

Taxonomy is the branch of biology that deals with the collection, identification, classification, labeling, and conservation of organisms. It is a detailed scientific study of the external and internal personnel of an organism that finds similarities and differences with others, which is important for its classification.

Systematics Definition:

On the other hand, systematics is related to the evolutionary relationships that exist between different groups of organisms. It seeks to identify organisms and/or groups of organisms with similar ancestral origins. It is about the number of evolutionary changes that have taken place in various ancestors. The word systematics means the proper arrangement of organisms and is comes from the Latin word “systema”.


Classification is not a step-by-step process, but each step involves an order of steps that represents a ranking or type. Because type is part of general classification autonomy, it is called classification autonomy, and all types together constitute classification autonomy.

Each type is defined as a classification unit which, in reality, refers to a standard and is usually referred to as a cart (pl: taxi).

Classification and hierarchical types can be illustrated with an example. Insects represent a group of organisms that share common features, such as three pairs of organs. This means that insects will identify the sortable concrete material so that a grade or type can be given.

Taxonomic studies of all known organisms have led to the development of common species such as state, filem or division (for plants), class, structure, family, genus, and species. All species, including plant and animal states, are among the lowest.

The question you can ask now is how to put an organism into different categories? The basic requirement is knowledge of the characters of a person or group of organisms. This helps identify similarities and differences between individuals of the same species and other species.

Scheme of Classification :

1. Species

species is defined as a group of individuals, capable of interacting to produce fertile.

It is the basic unit of taxonomy and helps us understand taxonomy and development. In general, the species is the lowest and indivisible taxonomic species, but in some cases, the species is divided into subspecies, which are considered the lowest unit.

Panthera leo (lion), Panthera tigris (tiger), Panthera Pardus (leopard) are the only species of Panthera. In the Asian throat scientifically named Panthera leo persica, Persica is a subspecies.

2. Genus (plural; genera)

Two or more species with common ancestry and similar characteristics are classified into one species are termed as Genus. Otherwise, a genus is a group of organisms associated with a common ancestor.

This category holds important classification status. In a bilateral appointment, a race cannot be named unless it is assigned to a race.

This type can be homogeneous or polynomial.

In monotypic, it has only one species [e.g. Homo sapiens (male)].

In contrast, polytheism includes many species for example Panthera leo (lion), Panthera tigris (tiger),

Panthera pardus (leopard), and Panthera onca (jaguar)].

3. Family

The next category has fewer related similarities than family, genus, and species. Families are classified based on the reproduction and reproductive facilities of the plant species.

In plants, for example, Solanum, Petunia, and Tadura are three different species in the Solanmia family.

In animals, for example, the panther, which includes lions, tigers, and leopards, belongs to the genus Felis (cat).

Likewise, if you follow the features of cats and dogs, you will find some similarities and some differences. They are divided into two distinct families, Felidae and Concida respectively.

4. Order

it includes related families.

Felidae -(cat), 

Viverridae -(civet), 

Hyaenidae -(hyena), 

Canidae -(dog),

Ursidae -(bear) 

 all these are included in the same order of Carnivora.

5. Class

This category of class includes two or more related orders like- 

Insectivora(hedgehog, mole), 

Chiroptera (bat), 

Primates (monkey and man), 

Rodentia (hareand squirrel),

 Edentata (ant eater), 

Carnivora (cat and dog), 

Cetacea (whale and dolphin) and 

Proboscidea (elephant)

These all are included in the class of Mammalia.

6. Phylum or Division (Plural; phyla)

some common features are included under a phylum or division Classes of different organisms. 

The phylum Chordata includes a number of classes like Aves, Cyclostomata, Chondrichthyes, Osteichthyes,  Amphibia, Reptilia, and Mammalia.

7. Kingdom

This is the highest taxonomic category. 

 one kingdom consists of Two or more related phyla. According to the classification of the Linnaean system, all plants come under the Kingdom, Plantae, while in under the kingdom, Animalia all animals come.

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