It is customary to subdivide all living organisms on our planet by official science into several large groups, including a great many species and subspecies. Why are bacteria secreted into a special kingdom? There are special reasons for this, allowing scientists to apply a similar classification. Let us deal with you in this matter.
Two groups
Why are bacteria secreted into a special kingdom? The answer is quite simple: all living creatures on our planet can be divided into 2 huge groups: prokaryotes and eukaryotes. The second includes fungi with plants and animals - multicellular organisms.
The first is widely represented by bacteria (also cyanogen algae with microscopic fungi). Representatives of the first group have fundamental differences that make it possible to isolate bacteria as special living creatures, separating them from all others. Why are bacteria secreted into a special kingdom? What is the difference, how did evolution distinguish them from others?
The main difference, or Why are bacteria secreted into a special kingdom?
The main difference that allows for such a classification: a prokaryote does not have a nucleus, ring DNA exists directly in the cytoplasm (this segment is called a nucleoid). In eukaryotes, on the contrary, the nuclei are clearly arranged, and the hereditary data are separated from the cytoplasm by their shells. Thus, we see that bacteria are quite different from other living creatures that live on Earth in their internal structure.
In addition, the vast majority of representatives of the other three kingdoms - animals with plants and mushrooms - are multicellular creatures. And almost all bacteria are unicellular.
Additional Features
There are additional reasons to understand why bacteria are secreted into a special kingdom.
- Since prokaryotes lack nuclei, there is no such thing as mitosis. They multiply by simply dividing the cells in half.
- Eukaryotes have large ribosomes, there are organoids: mitochondria and cell centers and the endoplasmic reticulum. And in bacteria, the role of membrane organoids is carried out by mesosomes - outgrowths on the plasma membrane, and ribosomes - small non-membrane organoids.
- A prokaryotic cell is much smaller than that of eukaryotes (about 10 times in diameter and about a thousand in volume).
Similarities of both groups
However, representatives of all groups have similarities in their structure. The cells of any living organism contain: firstly, a plasma membrane, secondly, the cytoplasm, and thirdly, ribosomes. This rule applies to all representatives of kingdoms in nature.
Manifold
Thus, we have established why bacteria secrete a special kingdom of living organisms. And this kingdom is truly huge and includes a wide species diversity, combining archaebacteria and eubacteria, microscopic fungi and blue-green algae. Under the bacteria, today's science refers to the smallest prokaryotic organisms, which are characterized by a cellular structure (dimensions - 0.1-30 microns).
It is physically impossible to see these creatures visually, without the help of special optical devices. It is no coincidence that before the invention of the microscope device, and even some time after, some luminaries of science (for example, the famous Karl Linnaeus belonged to them) denied the presence of these very important organisms in nature, attributing them to the game of imagination. To date, scientists have studied only about two and a half thousand varieties of this kingdom. But much remains to be discovered - after all, not all species are known. And a special branch of science, microbiology, is engaged in the study of various bacteria. She explores the most numerous inhabitants of our planet, which are invisible to the naked eye.