Biology Classification and nomenclature

Topics covered

`star` Identification
`star` Nomenclature
● Binomial Nomenclature
● Rules of Nomenclature
`star` Classification and Taxonomy
`star` Systematics


`color{blue} ul(mathtt ("Identification"))` : The process of recogizing an organism from others and assigning a pre-existing taxonomic group to an individual organism.

`color{green} ✍️ color{green} mathbf("KEY CONCEPT")`

● This step is `color{violet}"prerequisite"` to the process of classification and nomenclature.

● Taxonomic Identification is the process of recogizing an organism from others and assigning a pre-existing taxonomic group to an individual organism. It helps to `color{violet}"determine the proper place"` of an organism in the previously established plan of classification.

● Taxonomists often present `color{violet}"organized written descriptions of the characteristics"` of similar species so that other biologists can identify unknown organisms. Then detailed comparison is carried out between the characteristic features of various parts of the organism with the already known species, in order to determine their similarities and differences and assign them to a particular group or taxon.


`color{blue} ul(mathtt ("NOMENCLATURE"))` : It is the process of standardising the naming of living organisms according to international scientific rules, such that a particular organism is known by the same name all over the world.

`\color{green} ✍️ \color{green} \mathbf(KEY \ CONCEPT)`

● There are millions of plants and animals in the world and they vary in their vernacular names from place to place, even within the same country. This creates a lot of confusion to identify such organisms based on their local names.

● Thus to ensure that a particular organism is known by same name all over the world, the names of living organisms are `color{violet}"standardised"` by biologists by the process called nomenclature. For this purpose, scientific names are assigned to them..

● These scientific names are assigned by properly established procedures and scientific rules and accepted by biologists all over the world.

● For plants, scientific names are based on agreed principles and criteria, which are provided in `color{violet}"International
Code for Botanical Nomenclature (ICBN)"`. For animals, taxonomists have evolved `color{violet}"International Code of Zoological
Nomenclature (ICZN)"`

●The scientific names ensure that each organism has `color{violet}"only one name"`. They also ensure that such a name has not been used for any other known organism.

`color{purple}♣ color{green} "Just for Curiousity"`

Binomial nomenclature

`color{blue} ul(mathtt ("BINOMIAL NOMENCLATURE"))` : The system of providing a name with two components is called Binomial nomenclature

● This method was used for the first time on a large scale and thus established by `color{violet}"Carolus Linnaeus"`.

●This naming system uses a two word format. In this method, the scientific name for each organism has two components: the first is the name of the `color{violet}"genus (Generic name)"` and the second is the name of the `color{violet}"species (Specific name)"`.

● E.g., 𝘔𝘢𝘯𝘨𝘪𝘧𝘦𝘳𝘢 𝘪𝘯𝘥𝘪𝘤𝘢 for Mango. 𝘏𝘰𝘮𝘰 𝘚𝘢𝘱𝘪𝘦𝘯𝘴 for Humans. In this name 𝘔𝘢𝘯𝘨𝘪𝘧𝘦𝘳𝘢 represents the genus while 𝘪𝘯𝘥𝘪𝘤𝘢, is a particular species, or a specific epithet.

`color{purple}♣ color{green} "Just for Curious"`

●Binomial s'ystem was first proposed by `color{violet}"Gaspard Bauhin"` in his book - `color{violet}"Pinax Theatre Botanica"`

Other rules of Binomial Nomenclature

● Scientific names are generally derived from `color{violet}"latin"` (usually) or Greek, because they are dead languages

● The first word in a biological name represents the genus while the second component denotes the specific epithet.

● Both the words in a biological name, when handwritten or typed, are `color{violet}"separately underlined"`, or printed in `color{violet}"italics"` to indicate their Latinorigin.

● The first word denoting the genus starts with a `color{violet}"capital letter"` while the specific epithet starts with a `color{violet}"small letter"`.

● Name of the author appears `color{violet}"after"` the specific epithet, i.e., at the end of the biological name and is written in an abbreviated form, e.g., 𝘔𝘢𝘯𝘨𝘪𝘧𝘦𝘳𝘢 𝘪𝘯𝘥𝘪𝘤𝘢 Linn. It indicates that this species was first described by Linnaeus.

●Name of the author should be neither underlined nor in italics but written in Roman letters (simple alphabets).

`color{purple}♣ color{green} "Just for Curiousity"`

There are additional rules in assigning biological names which are different for ICBN and ICZN.

●In plant nomenclature (ICBN) `color{violet}"tautonyms are not valid"` i.e. :Generic name and specific epithet should not be same in plants.
eg. Mangifera mangifera

●But `color{violet}"tautonyms are valid"` in animal nomenclature (ICZN)
eg. 𝘕𝘢𝘫𝘢 𝘯𝘢𝘫𝘢 (Indian cobra). 𝘙𝘢𝘵𝘵𝘶𝘴 𝘳𝘢𝘵𝘵𝘶𝘴 (Rat)

Classification and Taxonomy

`color{blue} ul(mathtt ("TAXONOMY"))` : (Taxis : Arrangement, Nomos: Law). Taxonomy is the study of principles and processes of classification of organism into specific taxonomic groups.

`color{blue} ul(mathtt ("CLASSSIFICATION"))` : The process by which organisms are grouped into convenient categories based on some easily observable characters.

`color{green} ✍️ color{green} mathbf("KEY CONCEPT")`

● The scientific study of all the living organisms present on earth is nearly impossible. To make it `color{violet}"possible and convenient"`, the process of classification is carried out.

● Classification is the process by which organisms are grouped into `color{violet}"convenient categories"` based on some easily observable characters.

● The scientific term for these categories is `color{violet}"taxa"`.

● E.g., ‘Animals’, ‘Mammals’, ‘Dogs’ are all taxa – but we know that a dog is a mammal and mammals are animals. Therefore, ‘animals’, ‘mammals’ and ‘dogs’ represent taxa at different levels

● Hence, based on their distinctive characteristics, all living organisms can be `color{violet}"classified into different taxa"`. This process of classification is taxonomy.

●This word 'Taxonomy' was proposed by `color{violet}"A.P. de. Candolle"` in his book `color{violet}"Theories elementaire de Ia botanique"` (Theory of elementary' botany)

● The following characteristics are essential and form the basis of modern taxonomic studies.

`star` External structure and form – `color{violet}"Morphology"`
`star` Internal structure- `color{violet}"Anatomy"`
`star` Structure of cell – `color{violet}"Cytology/ Cell Biology"`
`star` Development process – `color{violet}"Developmental Biology / Embryology"`
`star` Ecological Information of organisms - `color{violet}"Ecology"`

● Hence, `color{Brown}"characterisation, identification, classification and nomenclature"` are the processes that are basic to taxonomy.