Nature is made up of a great diversity of living beings, among which we humans are. Within it, we can differentiate up to 5 kingdoms of nature : the animal, vegetable, fungi, protista and monera or procariota.

Each kingdom shares a number of common characteristics. In this article we’ll see which are the parameters that allow this classification, and which are the defining characteristics of each group. In addition, we mention examples of each kingdom.

The 5 kingdoms of nature

In the world of nature, there are five distinct kingdoms. The criterion that classified these kingdoms of nature was proposed, in 1977, by the microbiologist Carl Woese. Currently, this classification is the most agreed upon among many scientists who are experts in the taxonomy of living beings , and is based on other criteria.

The kingdoms of nature are:

  • The animal kingdom
  • The plant kingdom (plantae)
  • The Fungi Kingdom
  • The Protist Kingdom
  • The Monera Kingdom

Shared characteristics

The above-mentioned kingdoms of nature share a number of characteristics (which differ in each of the kingdoms), and these are as follows.

1. Cellular organization

This can be of two types: unicellular (a single cell) or pluricellular (millions of cells ). Examples of unicellular organisms are bacteria, some algae and fungi, protozoa… And, examples of pluricellular organisms are: humans, mammals…

2. Cell type

The cell of the organism can be, as in the previous case, of two types: eukaryotic or prokaryotic. Eukaryotic cells (typical of humans, for example) are those that have their hereditary material (DNA) enclosed within a double membrane.

Eukaryotic cells are much more complex than prokaryotic cells , which, in this case and unlike the previous ones, do not have a nucleus, and their DNA is located in the cytoplasm.

3. Type of reproduction

Reproduction can be of three types: sexual, asexual or spore reproduction.

4. Nutrition

Nutrition can also be of two types: heterotrophic or autotrophic . The first implies that organic matter is transformed into nutrients and energy, and that the animal obtains it from there. The second implies that the organism generates its own food, such as plants and some bacteria).

5. Locomotion

Living beings can move autonomously (autonomous locomotion) or not at all (immobile locomotion).

6. Type of breathing

Another characteristic shared by the kingdoms of nature is their type of breathing, which can be aerobic or anaerobic .

7. Other characteristics

Finally, each of the five kingdoms has its own (unique) and differentiated characteristics.

What are the organisms of each kingdom like?

Let’s get to know the characteristics (and examples) of each of the kingdoms of nature.

1. Animal kingdom

What forms the animal kingdom? Living organisms that have the following characteristics: they are pluricellular, heterotrophic, aerobically breathing, eukaryotic celled, sexually reproducing (in most cases) and autonomously moving organisms.

In turn, this kingdom is divided into two groups: the vertebrate organisms (with spine or backbone) and the invertebrate organisms (without spine or internal articulated skeleton). The former are subdivided into: fish, reptiles, mammals, birds and amphibians; the latter include: insects, worms and molluscs.

Some examples from the animal kingdom are: cows, tigers, lions, humans, bees, elephants, crocodiles, ostriches, penguins… In addition, some animals are microscopic, such as the tardive.

2. Plant kingdom

The second of the kingdoms of nature, the plant kingdom (also called the plantae kingdom), is made up of organisms that have the following characteristics: multicellular, autotrophic, eukaryotic, immobile, anaerobic and that can reproduce in two ways; sexually or asexually .

The fact that they are autotrophic means that the plants generate their own food, thanks to the process of photosynthesis. In fact, they are the only ones to do so, along with certain unicellular algae, belonging to the protista kingdom.

Examples from the plant kingdom are all types of plants (with or without flowers): magnolia, tulip, snow watermelon, banana plant, seed pine, royal fern…

3. Fungi Kingdom

The fungi kingdom is the kingdom of the mushrooms. In this case, it is made up of organisms with the following characteristics multicellular, aerobic, immobile, heterotrophic, with eukaryotic cell and that reproduce in three ways: by spores, sexually or asexually .

Interestingly, this kingdom was included as one of the five kingdoms of nature in 1969, thanks to the classification of the American ecologist Robert H. Whittaker (1920-1980). Specifically, Whittaker established the classification criteria according to cell type (prokaryotic or eukaryotic) and the level of cell organization (unicellular or pluricellular). This was achieved through the electric microscope.

But Whittaker went further and suggested including other classification criteria, already mentioned throughout the article: the type of nutrition (autotrophic or heterotrophic) and the type of reproduction (sexual or asexual).
Some examples from the fungi kingdom are: the star mushroom, the fly swatter, the devil’s cigar, the brewer’s yeast, the lacaria amethyst…

4. Protist Kingdom

The protista kingdom is characterized by the grouping of organisms that, due to their characteristics, cannot be included in any other kingdom . Thus, in a certain way it is a “tailor’s box”, because it includes both unicellular and multicellular, autotrophic and heterotrophic organisms, with sexual and asexual reproduction, etc.

Within the prokaryotic kingdom we find the protozoa (or protozoa) and the algae . Historically, this constitutes the kingdom of “the first eukaryotic forms of life”, and it is considered as such since 1866, when the German naturalist Erndt Haeckel (1834-1919) included it in the classification of the five kingdoms of nature. However, in his initial proposal, Haeckel included in the protista kingdom all unicellular organisms.

Examples from the protist kingdom (and which you have probably heard little about) are: amoeba, gregarine, paramecium, volvox, coanozoos, stentor, cercomonas…

5. Monera Kingdom

Finally, the last of the kingdoms of nature is the brown kingdom, also called the prokaryote kingdom. Within this kingdom we find all unicellular and prokaryotic organisms ; thus, they are microscopic beings. They are the only organisms with cells without a defined nucleus. Their genetic material is the simplest of all kingdoms.

These organisms were first defined by Ernst Haeckel in 1866. Later, the biologist Herbert Copeland (1902-1968) included bacteria in this group as well.
Some examples from the monera kingdom are: Chlamydia bacteria, Escherichia coli bacteria, Lactobacillus casei, Clostridium botulinum, Sorangium cellulosum, Bifidobacteria, Serpulina…

Bibliographic references:

  • Campbell N. and Reece J. (2007). Biology. Editorial Panamericana.
  • Raven P.H.; Evert R.F. & S.E.Eichhorn. (1991). Plant Biology, 2 vols. Reverté, S.A.