Kingdoms of nature

What are the kingdoms of nature?

The kingdoms of nature are the way living things are classified according to their characteristics.

Current science defines seven kingdoms of living things:

  • Kingdom Animalia (animals)
  • Kingdom Plantae (floors)
  • Kingdom Fungi (mushrooms)
  • Kingdom Protozoa (protozoa)
  • Kingdom Chromista (chromists)
  • Kingdom Archaea (arches)
  • Kingdom Bacterium (bacteria)

This classification was proposed in 2015 by researcher Michael Ruggiero. Before, the classification created by the American ecologist and botanist Robert Whittaker was used, in which five kingdoms of nature were classified, including the Monera kingdom. But this classification is no longer used.

It is currently known that the organisms that were part of the Monera kingdom actually have different characteristics from each other and regrouped in the kingdoms Archaea Y Bacterium.

Characteristics of the kingdoms of nature

The criteria for deciding the way in which living beings are grouped in each kingdom respond to certain common characteristics between species, such as:

  • Cell organization: unicellular or multicellular.
  • Cell type: eukaryotic (with a defined nucleus) or prokaryotic (without a defined nucleus).
  • Reproduction: sexual or asexual
  • Nutrition: heterotrophic (compounds generated by other organisms) or autotrophic (compounds generated by the body itself).
  • Locomotion: autonomous or immobile.
  • Respiration: aerobic (in the presence of oxygen) or anaerobic (in the absence of oxygen).
  • Other unique characteristics of each kingdom.

Classification of the kingdoms of nature

Currently, the existence of seven kingdoms is considered:

1. Kingdom Animalia (animals)

The turtle belongs to the animal kingdom.

The kingdom Animalia or animal is composed of organisms with a defined cell nucleus, heterotrophs, that breathe oxygen, reproduce sexually and move autonomously.

They are complex living beings, with specialized tissues and organs that are classified into two large groups:

Vertebrates: they are the organisms with vertebral column and skull. They are subdivided into fish, amphibians, reptiles, birds, and mammals.

Invertebrates: they lack backbones and include insects, mollusks, and worms.

These are some examples of organisms from the animal kingdom:

  • Southern Right Whale (Eubalaena australis).
  • Sea turtle (Chelonioidea).
  • Guacamaya flag (Ara macao).
  • Lion (Panthera leo).
  • Human being (Homo sapiens)

2. Kingdom Plantae (floors)

A specimen of the cherry tree (Prunus). All plants belong to the kingdom Plantae.

The kingdom Plantae It is composed of multicellular organisms with defined nuclei (eukaryotes), immobile and aerobic respiration, which reproduce sexually or asexually. These are basically all plant species, with or without flowers.

Plants are the only living beings that are autotrophs, thanks to the generation of their own food through photosynthesis, with the exception of some unicellular algae of the kingdom Chromista.

These are some examples of kingdom organisms Plantae:

  • Moon orchid (Phalaenopsis amabilis)
  • Sequoia (Sequoia sempervirens)
  • Pine tree (Pinus)
  • Lemon Tree (Citrus x limon)
  • Tea (Camellia sinensis)

3. Kingdom Fungi (mushrooms)

Mushrooms belong to the kingdom fungi.

They belong to the kingdom Fungi, or kingdom of fungi, organisms with defined nuclei, immobile and aerobic respiration that reproduce through spores sexually or asexually. For a long time they were considered part of the kingdom Plantae, but today they are considered an independent kingdom.

The fungi feed on organic materials discarded by other species. They do this by symbiosis with plants with which they exchange food, or by parasitic relationship with other organisms, such as the fungus Trichophyton rubrum, which causes a skin disease commonly called "athlete's foot."

These are other examples of the kingdom Fungi:

  • Mushroom (Agaricus bisporus).
  • Mold.
  • Painted apron or false apricot (Amanita muscaria).
  • The fungus that is used in the production of penicillin (Penicillium chrysogenum)
  • Scarlet copic (Sarcoscypha coccinea).

4. Kingdom Protozoa (protozoa)

An amoeba, an organism of the kingdom Protozoa

The kingdom Protozoa It is made up of all unicellular organisms that are not classified in any of the other identified kingdoms. They can be both aerobic or anaerobic, autotrophic or heterotrophic, of sexual or asexual reproduction. Hence, it is difficult to establish common characteristics in this kingdom.

They are defined as the kingdom of the first eukaryotic forms of life and the protozoa and amoebas belong to it. Some examples are:

  • The giardia (Giardia intestinalis), an intestinal parasite.
  • Paramecia (Paramecium), microorganisms abundant in stagnant fresh water.

5. Kingdom Chromista (chromists)

It groups together all organisms with a defined cell nucleus, with photosynthetic metabolism and a rigid cell covering that protects them from the outside. They also have cilia, elongated cellular structures that allow them to feed and move.

Although this kingdom has existed since 1981, it was not until 2015 that it was included as part of the general classification of living beings proposed by Michael Ruggiero and his collaborators. For this reason, it is not usually found in traditional classification systems that have not been updated.

These are some examples from the Chromist realm:

  • Diatoms, the most common type of phytoplankton.
  • Brown algae, mostly present in the ocean.
  • Golden algae (Chrysophyta), common algae in fresh water.
  • Foraminifera are microorganisms that develop an exoskeleton or shell and are mainly found in salty waters.

6. Kingdom Archaea (arches)

Different types of archaea seen under the microscope.

This kingdom is made up of prokaryotic organisms, that is, without a defined cell nucleus. Their diet can be autotrophic or heterotrophic, and they can feed on a large number of compounds ranging from sugars to ammonia and hydrogen. In addition, they reproduce by binary fission, dividing their cytoplasm to generate two new cells.

For a long time, the archaea were part of the kingdom Monera. However, this realm is no longer used in current classifications; and as the archaea have their own characteristics, they were renamed.

Some examples of microorganisms that belong to the kingdom of archaea are:

  • Haloquadratum walsbyi (arches with a square aspect).
  • Halobacterium (archaea that live in environments with high concentrations of salt).
  • ARMAN (Archaeal Richmond Mine Acidophilic Nanoorganisms) are archaea that live in acidic environments.

7. Kingdom Bacterium (bacteria)

Bacterium Escherichia Coli, causing intestinal infections in humans.

To this kingdom belong prokaryotic microorganisms and with a cell wall of peptidoglycan or murein, a compound that helps bacteria to be more resistant to external agents.

The presence of murein helps classify bacteria into two types:

Gram-negative: they have a layer of up to 10% murein between the outer and inner cell membranes.

Gram-positive: they only have a murein layer on the outer membrane, but it can be as high as 90%.

Bacteria are the most abundant organisms on the planet. Although they are usually associated with diseases, they also have a fundamental role in the balance of ecosystems, since many species are responsible for degrading the organic compounds present in soils.

Here are some examples of bacteria:

  • Sorangium cellulosum, a bacteria found in soils.
  • Lactobacillus acidophilus (Lactobacillus acidophilus), is a bacterium found in the digestive tract of animals and humans, as well as in foods of dairy origin, such as yogurt.
  • Clostridium botulinum, a bacterium that generates the toxin that causes botulism, a type of poisoning that can be fatal.
  • Chloroflexus aurantiacus, can survive temperatures above 45 degrees and is usually found in hot springs.
  • Escherichia coli, is a bacterium that can cause infections in the intestinal tract of animals and humans.

You may also be interested in reading about:

  • Characteristics of living beings
  • Kingdom Animalia
  • Kingdom Plantae
  • Kingdom Fungi
  • Monera Kingdom
  • Cell prokaryotic
  • Cell eukaryote

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