Content
- Whittaker's 5 Realms of Living Beings
- 1. Monera Kingdom
- 2. Protist Kingdom
- 3. Kingdom Fungi
- 4. Plant Kingdom
- 5. Kingdom Animalia
- Do you want to know more about Earth's living beings?
All living organisms are classified into five kingdoms, from small bacteria to humans. This classification has fundamental bases that were established by the scientist Robert Whittaker, which contributed enormously to the study of beings that live on Earth.
Do you want to know more about the 5 realms of living beings? In this article by PeritoAnimal, we will talk about the classification of living beings into five kingdoms and their main characteristics.
Whittaker's 5 Realms of Living Beings
Robert Whittaker was a leading plant ecologist in the United States who focused on the area of plant community analysis. He was the first person to propose that all living things be classified into five realms. Whittaker was based on two fundamental characteristics for his classification:
- Classification of living beings according to their diet: depending on whether the organism feeds through photosynthesis, absorption or ingestion. Photosynthesis is the mechanism that plants have to take carbon from the air and produce energy. Absorption is the method of feeding, for example, bacteria. Ingestion is the action of taking nutrients by mouth. Learn more about the classification of animals in terms of food in this article.
- Classification of living beings according to their level of cellular organization: we find prokaryote organisms, unicellular eukaryotes and multicellular eukaryotes. Prokaryotes are unicellular organisms, that is, formed by a single cell, and are characterized by not having a nucleus inside them, their genetic material is found dispersed within the cell. Eukaryotic organisms can be unicellular or multicellular (made up of two or more cells), and their main characteristic is that their genetic material is found inside a structure called a nucleus, inside the cell or cells.
Joining the characteristics that make up the two previous classifications, Whittaker classified all living beings in five kingdoms: Monera, Protista, Fungi, Plantae and Animalia.
1. Monera Kingdom
The kingdom monera includes unicellular prokaryotic organisms. Most of them feed through absorption, but some are able to carry out photosynthesis, as is the case with cyanobacteria.
inside the kingdom monera we found two subrealms, the of archaebacteria, which are microorganisms that live in extreme environments, for example, places with very high temperatures, such as thermal cesspools on the ocean floor. And also the subkingdom of the eubacteria. Eubacteria can be found in almost every environment on the planet, they play important roles in Earth's life and some cause disease.
2. Protist Kingdom
This realm includes the organisms single-celled eukaryotes and some multicellular organisms simple. There are three main subrealms of the Protist realm:
- Algae: unicellular or multicellular aquatic organisms that carry out photosynthesis. They vary in size, from microscopic species, such as micromonas, to giant organisms that reach 60 meters in length.
- Protozoa: mainly unicellular, mobile, and absorption-feeding organisms (such as amoebas). They are present in almost all habitats and include some pathogenic parasites of humans and domestic animals.
- protist fungi: protists who absorb their food from dead organic matter. They are classified into 2 groups, slime molds and water molds. Most fungal-like protists use pseudopods ("false feet") to move.
3. Kingdom Fungi
The kingdom fungi it's composed by multicellular eukaryotic organisms that feed through absorption. They are mostly decomposing organisms, which secrete digestive enzymes and absorb small organic molecules released by the activity of these enzymes. In this kingdom are found all kinds of fungi and mushrooms.
4. Plant Kingdom
This realm comprises the multicellular eukaryotic organisms that do photosynthesis. Through this process, plants produce their own food from the carbon dioxide and water they capture.Plants don't have a solid skeleton, so all their cells have a wall that keeps them steady.
They also have sex organs that are multicellular and form embryos during their life cycles. The organisms we can find in this realm are, for example, mosses, ferns and flowering plants.
5. Kingdom Animalia
This realm is composed of multicellular eukaryotic organisms. They feed by ingestion, eating food and digesting it in specialized cavities within their body, such as the digestive system in vertebrates. None of the organisms in this kingdom have a cell wall, which occurs in plants.
The main characteristic of animals is that they have the ability to move from one place to another, more or less voluntarily. All animals on the planet belong to this group, from marine sponges to dogs and humans.
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