WHAT ARE TAXONOMIC LEVELS? (WITH EXAMPLES) - BIOLOGY - 2024

The taxonomic levels or taxa are a way of classifying species. In taxonomy, there are eight levels: domain, kingdom, phylum, class, order, family, genus, and species. Taxonomic levels are organized from general to specific, with “domain” being the most general category and “species” the most specific category.

On the other hand, each taxonomic level is made up of a group of individuals from the immediate lower level. For example, the domain is a set of kingdoms, a kingdom is a set of divisions, a division is a set of classes, and so on until reaching the species, which are the basic unit of taxonomy.

Example of the taxonomic classification of the red fox (Vulpes vulpes). Domain (eukaryote), Kingdom (animalia), Phylum (chordates), Class (mammals), Order (carnivores), Family (canids), Genus (Vulpes), Species (Vulpes vulpes). Wikpedia.org

Taxonomic levels not only allow species to be classified, but also give each of these a unique name. In fact, the name of a species is composed of two Latin words: the first corresponds to the taxonomic level of the genus, while the second is the specific characteristic of the species.

All this contributes to linguistic normalization in the area of ​​natural sciences.

The 8 taxonomic levels

There are eight taxonomic levels, organized from the most inclusive to the most exclusive. These levels are: domain, kingdom, phylum, class, order, family, genus, and species.

- Domain

Domain is the most inclusive category of all. This level takes cells to establish the difference between individuals. This means that to determine which domain a species belongs to, it must be determined whether it has eukaryotic or prokaryotic cells.

In the case of prokaryotic cells, other elements are taken into account, such as the location of the cell and the material from which the cell wall is made.

In the current taxonomy, three domains are recognized: Bacteria, Archaea, and Eukarya.

- Kingdom

The domains are divided into kingdoms. Currently there are six kingdoms: Archaebacteria, Eubacteria, Protista, Fungi, Plantae and Animalia.

Archaebacteria and eubacteria

These two kingdoms bring together individuals with prokaryotic cells, in which the genetic material is dispersed in the cytoplasm of the cell and not contained in the nucleus. Previously, these two kingdoms made up one: the Monera kingdom.

Protista

The Protista kingdom is made up of individuals with eukaryotic cells (those that have the genetic information contained in the nucleus of the cell).

The Protista kingdom is made up of single-celled organisms, which can resemble both animals (such as protozoa) and plants (such as single-celled algae).

Fungi

The Fungi kingdom is made up of eukaryotic organisms, better known as fungi.

Plantae

The kingdom Plantae, also called the plant kingdom, is made up of autotrophic eukaryotic organisms.

The latter means that these individuals are capable of producing their own food, which they do through photosynthesis.

Animalia

The Animalia kingdom (animal kingdom) is made up of heterotrophic eukaryotic organisms (which do not make their own food).

- Phylum

The phylum, also called phylum, division or type, includes a series of organisms whose basic organization is similar.

For example, the phylum Cordata (or chordates) is composed of organisms with a notochord (a structure that runs through the spine of some vertebrate animals).

- class

A class comprises several orders of organisms.

- Order

Composed of families that share the most fundamental characteristics. For example, the order Carnivora is made up of carnivorous animals.

- Family

The family is made up of a set of genders that resemble each other. For example, in the Canidae family (the Canidae family) there are several similar genera, such as: Canis, Vulpes, Cerdocyon, among others.

- Gender

The genus constitutes a set of species that are related to each other. For example, the genus Canis brings together a series of individuals that have more or less similar characteristics, such as dogs, wolves and coyotes.

The genus constitutes the first part of the scientific name of a species.

- Species

Also called biological species, it is a category that brings together individuals that are capable of effectively reproducing among themselves, generating fertile offspring that can guarantee the continuity of the species.

Examples of classification at taxonomic levels

Example n ° 1: The common dog

Domain: Eukarya

Animalia Kingdom

Phylum: Cordata

Class: Eutheria

Order: Carnivora

Family: Canidae

Genus: Canis

Species: Canis familiaris

Example n ° 2: Common beans or beans

Domain: Eukaryota.

Kingdom: Plantae

Phylum: Trecheophyta

Class: Angiospermae

Order: Leguminoseae

Family: Papilioneaceae

Genus: Phaseolus

Species: Phaseolus vulgaris

Example # 3: Penicillin

Domain: Eukarya

Fungi kingdom

Phylum: Ascomycota

Class: Eurotiomycetes

Order: Eurotiales

Family: Trichocomaceae

Genus: Penicillium

Species: Penicillium notatum

Example n ° 4: Trypanosoma cruzi, cause of Chagas disease

Domain: Eukarya

Protist kingdom

Phylum: Euglenozoa

Class: Zoomastigophorea

Order: Trypanosomatida

Family: Trypanosomatidae

Genus: Trypanosoma

Species: Trypanosoma cruzi

Example n ° 5: Caldisphaera draconis

Domain: Archaea

Kingdom: Archaebacteria

Phylum: Crenarchaeota

Class: Thermoprotei

Order: Acidilobales

Family: Caldisphaeraceae

Genus: Caldisphaera

Species: Caldisphaera draconis

Taxonomic levels and the linguistic normalization of species

A single species can have more than one common name in each country, society or culture. However, thanks to the taxonomic classification, the species have only one scientific name. This is called linguistic normalization.

This normalization is based on the binominal nomenclature of the taxonomy, which means that the name of the species consists of two names.

Of these, the first name is that of the genus (seventh taxonomic level in descending order) while the second is an epithet (particular characteristic of the species).

For example:

Canis familiaris (common dog)

Canis lupus (wolf)

Canis latrans (coyote)

The three species mentioned above belong to the genus Canis, as its scientific name indicates. We know that these are diverse species because each one has a different epithet.

Artificial classification

All taxonomic levels (except species) constitute artificial classifications, since they do not really exist in nature.

The levels from domain to genus have been created by humans, based on the observable characteristics of the species.

For its part, the concept of species is the only one that really exists in nature, since it is delimited by the reproductive nature of individuals.

References

1. Taxonomic Rank. Retrieved on July 23, 2017, from en.wiipedia.org
2. Levels of Taxonomy. Retrieved on July 23, 2017, from thoughtco.com
3. Taxonomic classification. Retrieved on July 23, 2017, from learner.org
4. The levels of classification. Retrieved on July 23, 2017, from boundless.com
5. Taxonomy. Retrieved on July 23, 2017, from britannica.com
6. Taxonomic Rank. Retrieved on July 23, 2017, from carm.org
7. Linnean Taxonomy. Retrieved on July 23, 2017, from eebweb.arizona.edu.