Biologists follow universally accepted principles to provide scientific names to known organisms. Each name has two components – the Generic name (genus) and the specific epithet (species name). Hence the system is called binomial nomenclature.

We can compare the generic (genus) name with our surname. We share our surname with other members of the family. similarly, a species can share a generic name with other members of the genus. The species name is like our name. It is possessed by only one kind of organism. It does not share it with any other member of the genus. This system of providing a name with two components is called Binomial nomenclature. This naming system given by Carolus Linnaeus is being practiced by biologists all over the world.

Rules of Nomenclature:

These rules are given by the International Code of Biological Nomenclature.

• Biological names are generally in Latin and written in italics.
• They are Latinized or derived from Latin irrespective of their origin.
• The first word in a biological name represents the genus which is a simple noun while the second component is a descriptive adjective which denotes the specific epithet (character).
• Both the words in a biological name, when handwritten, are separately underlined or printed in italics to indicate their Latin origin.
• The first word denoting the genus starts with a capital letter while the specific epithet starts with a small letter.
• The generic, as well as a specific name, do not generally have less than three letters and more than thirteen letters. It can be illustrated with the example of Mangifera indica (mango).
• Usually, the name of the author appears after the specific epithet, i.e., at the end of the biological name and is written in an abbreviated form or in full. e.g. Mangifera indica L. It indicates that this species was first described by Linnaeus.  This method of mentioning the author’s name is called a citation.
• To avoid confusion, no two generic names in any kingdom can be the same. However, species name can be repeated when genera are different. E.g. Mangifera indica (mango) and Azadirachta indica (neem)

Advantages of Binomial Nomenclature:

• These names are simple and meaningful, precise and standard as they are accepted universally.
• Using this system confusion created by vernacular or local language can be avoided. For e.g. Ipomoea batatas is called sweet potato (English), Shakarkand  (Hindi), Ratalu (Marathi), Meetha alu (Bengali), Kandmul (Telugu) and Janasu (Kannada)3. It is easy to understand and remember.
• It indicates a phylogenic (evolutionary) history of that species.
• It helps to understand the relationship between organisms and groups of organisms.

Names of Some Plants Using Binomial Nomenclature:

Names of Some Animals Using Binomial Nomenclature:

Science > Biology > General Biology > Diversity of Living Organisms > Binomial Nomenclature

The post Binomial Nomenclature appeared first on The Fact Factor.

In this article, we shall study the taxonomic hierarchy and the concept of species.

The Concept of Species:

A group of living organisms consisting of similar individuals capable of exchanging genes or interbreeding is called species. They are usually described in terms of their characteristics so that organisms which have a lot of similarities are grouped as the same species.

Characteristics of Species:

• Members of species resemble one another more than with individuals of any other species.
• Their morphological characters are similar.
• They interbreed with other individuals within the same group to produce fertile offsprings
• under natural conditions.
• They share a common gene pool. Have similar karyotype and genetic material. They have descended from a common ancestor.
• They are anatomically similar.
• Their biochemistry is similar.

Taxonomic Hierarchy:

• Taxon (Pl – taxa): Taxon is a group of living organisms which is used to represent a concrete unit of classification. It may be large or small. In a taxonomic hierarchy, there are a minimum of seven categories (taxa). Various taxonomic categories are species, genus, family, order, class, phylum, kingdom, and domain.
• Category: A category is a rank or level in the hierarchical classification of organisms. In the hierarchy of categories, the kingdom is the highest and species is the lowest category.

Units of Classification:

Acronym: King Philip’s’s Classmates Sing a Song Of Family Genius Specially

Species:

It is the smallest and basic unit of classification. Taxonomic studies consider a group of individual organisms with fundamental similarities as a species. Thus all the individual members belonging to particular species show all similar characters and can breed among themselves to produce a similar type of organism. We should be able to distinguish one species from the other closely related species based on the distinct morphological differences. All the china rose (Hibiscus) plants are grouped under a species rosa Sinensis. All the potato plants are grouped under species tuberosum.

• House crow commonly called the Indian crow (Corvus splendens) and forest crow commonly called jungle crow or raven (Corvus macrorhynchos) have the same genus but they can not breed among themselves. Hence these are two different species.

• Horse (Equus cabalus) and ass (Equus asinus) are of the same genera but are two different species because they do not breed among themselves. The mule is an artificial hybrid of horse and ass is sterile i.e. it cannot reproduce. Hence the mule is not a species.

• Lion (Panthera leo), Leopard (Panthera pardas) and Tiger (Panthera tigris) belong to the same genus Panthera but their species are leo, pardas and tigris respectively.
• The plants Tomato (Solanum lycopersicum), Potato (Solanum tuberosum) and Brinjal (Solanum melongena) belong to the same genus Solanum but their species are lycopersicum, tuberosum, and melongena respectively.

Genus (Pl – genera):

It is a group of organisms of closely related species, which resemble one another in certain characters. The genus may or may not have more than one species. Genera with only one species are called monotypic while those with more than two are called polytypic.

• Banyan tree (Ficus benghalensis) and fig tree (Ficus carica) differ in shape, size, leaves but have a similar reproductive organ like inflorescence. Hence they are of the same genera.
• Lion (Panthera leo), Leopard (Panthera pardas) and Tiger (Panthera tigris) belong to the same genus Panthera. Genus Panthera is different from other genera of cats. Domestic cat and tiger belong to the same family but their genera are different.

• The plants Tomato (Solanum lycopersicum), Potato (Solanum tuberosum) and Brinjal (Solanum melongena) belong to the same genus Solanum.

Family:

It is the next category higher to the genus. It is a group of organisms of closely related genera, which resemble one another in certain characters.

• Domestic cat (Felis domestica) and Lio (Panthera leo) belong to cat family Felidae because both of them possess a similar structure and has retractive claws.
• The family of Dogs and Foxes is Canidae.
• Family Gramineae: Wheat, Rice, and maize.
• Family Leguminosae: Gram, Pea, Soyabean
• Family Solanaceae: Genera Solanum, Petunia, Datura

Order:

It is next category higher to the family. It is a group of organisms of closely related families, which resemble one another in major characters. It should be noted that the order is higher taxonomic categories. Hence very few similar characters are shown by members.

• Both the tiger (Panthera tigris) and the wolf (Cannis lupus) possess jaws with powerful incisors and large sharp canines. This adaptation is for flesh-eating. Hence tiger and wolf have the same order Carnivora. Thus Order Carnivora includes families Felidae and Canidae.
• In plant, order, Rosales includes families Leguminosae and Rosaceae.

Class:

It is the next category higher to the order. It is a group of organisms of closely related sub-classes or order, which resemble one another in certain characters. The similarities in the orders of a class are still less than in the families of an order.

• Chordates such as rats, dogs, bats, monkeys, camel are characterized by a hairy exoskeleton, milk glands (mammari glands)and external ears, belong to the same class Mammalia. Class Mammalia includes order Carnivora (has carnivorous animals like lion, tiger, leopards, etc.) and order Primata (includes man, monkey, Chimpanzee, Gorilla, Gibbons, etc)
• All vascular plants are categorized under class Tracheophyta.

Phylum (for animals) and Division (for plants):

It is the next category higher to the class. It is a group of organisms of closely related class, which resemble one another in certain characters. In the case of plants, the term Division is used for the phylum

• all animals which have a notochord present in embryo belong to the phylum Chordata. Classes like Pisces (fishes), Amphibia (frogs and toads), Reptilia (snakes and lizards), Aves (birds) and Mammalia (mammals) are all grouped into a single phylum Chordata.
• All flowering plants are grouped into a single division Angiosperms.

Kingdom:

It is the next category higher to the phylum/division. It is a group of organisms of closely related phyla, which resemble one another in major characters. All animals are grouped into Kingdom Animalia and all plants are grouped into Kingdom Plantae.

Science > Biology > General Biology > Diversity of Living Organisms > Taxonomic Hierarchy

The post Taxonomic Hierarchy appeared first on The Fact Factor.