The 8 main characteristics of the Kingdom Monera

A review of the characteristics of the Kingdom Monera, a category used to classify microorganisms.

There are many living beings that populate the Earth. The different types of animals and plants are probably the first that come to mind when we think of living beings, but they are not the only ones: there are other creatures such as fungi or algae, and even many that are invisible to the naked eye, such as bacteria.

Bacteria are often a source of fear for the population, as they are associated with dangerous diseases, but the truth is that some of them are also part of our bodies and help us to carry out processes such as digestion.

When we talk about bacteria, we are talking about one of the main representatives of the kingdom of moneras, according to the division of the different living beings into kingdoms. This kingdom, the oldest of all and the first to emerge as well as the most abundant, possesses a large number of unique properties that distinguish them from the rest of the kingdoms. That is why throughout this article we are going to talk about the main we are going to talk about the main characteristics of the monera kingdomThe main characteristics of the monera kingdom, to understand how are the forms of life that are usually included in this concept.

What is the Kingdom Monera? A brief description

We denominate kingdom monera to a group of living beings classified in the same category due to the existing similarities between all its members and the differences for the rest of the and the differences with the rest of the group of living beings, following the classification into kingdoms proposed by Ernst Haeckel and later expanded by several authors.

The kingdom monera groups a wide group of unicellular beings without a cellular nucleus.bacteria, whose DNA is scattered in the cytoplasm and characterized by a great simplicity in their configuration (in fact monera comes from the Greek "moneres", simple). This kingdom is traditionally known as the kingdom of bacteria, which can be classified by their shape into cocci if they resemble spheres, bacilli if they are rod-shaped, spirilla if they resemble a corkscrew or a spring, and vibrios if they are comma-shaped.

However, it also includes the group of cyanobacteria, which differ from bacteria in that they are unicellular algae capable of photosynthesis, and archaeobacteria (which have an internal functioning more similar to the other kingdoms than to bacteria and are capable of surviving in the most extreme conditions).

Curiously, despite being probably the most phylogenetically the most primitive group phylogenetically speaking (they were the first inhabitants of the planet) and the one that has the largest presence in the world, was the last to be discovered (although not incorporated into the classification of kingdoms, this honor corresponding to the fungi kingdom). It was incorporated as its own kingdom by Alexander Barkley in 1939 (although divided and later by Herbert Copeland as we know it today.

However, today the concept of the kingdom monera, and even the kingdom as a classificatory system, is increasingly out of use.. Furthermore, it has been observed that the representatives of the kingdom monera should be separated into two: archaea (including archaeobacteria) and bacteria (including both bacteria and cyanobacteria), due to the great differences between these groups.

Main characteristics of the Kingdom Monera

As previously mentioned, the monkey kingdom presents a series of characteristics and particularities that have led to its classification as one of the main types of living beings. In this sense, we can highlight the following characteristics as the most relevant.

1. They are prokaryotic organisms

One of the distinctive characteristics of the monera kingdom is that all of its representatives are prokaryotic, that is, they are living beings that do not have a cell nucleus. Thus, the DNA is not condensed and protected by a structure, but is spread throughout the cell nucleus.The DNA is not condensed and protected by a structure, but is distributed throughout the cytoplasm of the cell. It is the only one of the kingdoms that presents this characteristic, being the most primitive group of living beings.

2. Circular DNA

Linked in part to the previous point. If we think of DNA, the image of a double helix probably comes to mind, just as it occurs in human DNA strands. In the monkey kingdom, however, this type of distribution does not occur, but rather a closed, circular double-stranded structure. instead, the structure is in the form of a closed, circular, double-stranded structure.. Curiously, this structure is also found in the mitochondria of animals.

3. They are unicellular

While animals and plants are composed of millions of cells, moneras are much simpler organisms that are composed of millions of cells. are much simpler organisms that are composed of a single cell.. They do not form tissues or organs, nor do they need them to survive. Despite this, some specimens are grouped in large assemblies (although they are still living beings at the individual level).

4. Asexual reproduction

Another characteristic of this kingdom is that all its components present mostly asexual reproduction and based on mitosis.Bacteria reproduce through binary fission or bipartition, in which the same individual generates copies of its DNA and divides into identical and independent individuals, or twinning, in which a miniature version of itself is generated on the body and grows until it detaches.

However, in some cases there is a genetic exchange with other bacteria, through contact or through the transformation of DNA within the being itself.

5. Methods of displacement

Another aspect to take into account is that although some are immotile, in many cases moneras can also move. This is because they may have flagella and cilia with which they can move in a helical or forward by means of helical movement or from front to back and vice versa.

6. Size

The components of the monera kingdom are the smallest creatures in existence. (with the possible exception of viruses, if we consider them living beings), often no more than a few micrometers.

7. Feeding methods

Moneras can have different feeding systems. As a rule they are heterotrophic, i.e. they feed on external elements or on other creatures.. In this sense they can be parasitic, symbiotic or saprophytic (they feed on the waste of other creatures).

However, many bacteria and all cyanobacteria are autotrophic, generating the nutrients necessary for life from inorganic matter, for example through photosynthesis.

8. Respiration

Most living things are obligate aerobes, i.e. they need oxygen to survive. However, in the monkey kingdom there are specimens that can survive without oxygen (facultative anaerobes) or even for which oxygen is lethal (in fact, one of the first mass extinctions occurred among obligate anaerobic organisms when this element began to prevail in our atmosphere).

Bibliographical references:

• Campbell, N. (2003). Biology: Concepts & Connections. San Francisco: Pearson Education.
• Margulis, L. and Schwartz, K. V. (1982). Five Kingdoms. An Illustrated Guide to the Phyla of Life on Earth. W.H. Freeman, San Francisco.
• Murat, D.; Byrne, M.; Komeili, A. (2010). Cell Biology of Prokaryotic Organelles. Cold Spring Harbor Perspectives in Biology 2(10). doi:10.1101/cshperspect.a000422.