Eukaryotes are the most progressively organized organisms. In our article, we will consider which of the representatives of wildlife belongs to this group and what features of the organization allowed them to occupy a dominant position in the organic world.
Who are eukaryotes?
According to the definition, eukaryotes are organisms whose cells contain a shaped nucleus. These include the following kingdoms: Plants, Animals, Mushrooms. Moreover, it does not matter how complex their body is. Microscopic amoeba, volvox colonies, giant sequoia - they are all eukaryotes.
Although the cells of these tissues can sometimes be deprived of the nucleus. For example, it is not in red blood cells. Instead, this blood cell contains hemoglobin, which carries oxygen and carbon dioxide. Such cells contain a nucleus only at the first stages of their development. Then this organelle is destroyed, and with it the ability of the whole structure to divide is lost. Therefore, having fulfilled their functions, such cells die.
The structure of eukaryotes
The cells of all eukaryotes have a nucleus. And sometimes not even one. This two-membered organelle contains in its matrix genetic information encoded in the form of DNA molecules. The core consists of a surface apparatus, which provides the transport of substances, and the matrix - its internal environment. The main function of this structure is the storage of hereditary information and its transfer to daughter cells formed as a result of division.
The internal environment of the core is represented by several components. First of all, it is karyoplasm. It contains nucleoli and chromatin strands. The latter are composed of proteins and nucleic acids. It is during their spiralization that chromosomes are formed. They are directly carriers of genetic information. Eukaryotes are organisms in which in some cases two types of nuclei can form: vegetative and generative. A vivid example of this is ciliates. Its generative nuclei preserve and transmit the genotype, and vegetative ones regulate protein biosynthesis.
The main differences between pro and eukaryotes
Prokaryotes do not have a designed core. This group of organisms includes the only kingdom of wildlife - Bacteria. But such a structural feature does not mean at all that there is no carrier of genetic information in the cells of these organisms. Bacteria contain ring DNA molecules - plasmids. However, they are located in the form of clusters in a certain place of the cytoplasm and do not have a common shell. Such a structure is called a nucleoid. There is one more difference. DNA in prokaryotic cells is not bound to core proteins. Scientists have established the existence of plasmids in eukaryotic cells. They are found in some semi-autonomous organelles, for example, in plastids and mitochondria.
Progressive structural features
Organisms that differ in more complex structural features at all levels of the organization belong to eukaryotes. First of all, this relates to the method of reproduction. The bacterial nucleoid provides the simplest of them - cell division in two. Eukaryotes are organisms that are capable of all kinds of reproduction of their own kind: sexual and asexual, parthenogenesis, conjugation. This ensures the exchange of genetic information, the appearance and consolidation of a number of useful traits in the genotype, and, therefore, the best adaptation of organisms to constantly changing environmental conditions. This feature allowed eukaryotes to take a dominant position in the system of the organic world.
So, eukaryotes are organisms in the cells of which there is a formed nucleus. These include plants, animals and mushrooms. The presence of a core is a progressive feature of the structure, providing a high level of development and adaptation.