One of the points of the well-known theory of cellular structure is the statement about the appearance of new cells from the original, that is, maternal. But this can happen in two ways. One of them is mitosis. It is essential for the process of reproduction of their own kind. What cells are formed as a result of mitosis, what is their number and features of the process - all this will be discussed in detail in our article.
Cell cycle
A cell of any organism is able to exist in the interval between its two divisions or from the beginning of this process until the moment of death. This stage of time is the cell cycle. It includes the stages of the division process itself and a certain period of time between them, which is called interphase. During this period, cell growth and the formation of nutrients.
But one of the mostimportant points is the process of duplication of DNA macromolecules. All the genetic information about the cell is encrypted there.
How does cell division happen
Meiosis reproduces sperm and eggs. The essence of this process is the formation of four haploid gametes from the mother cell with a double set of chromosomes. For this reason, it is also called reduction division. This is very important, because during fertilization, a new organism arises from germ cells, containing half of the hereditary information from the mother and father. And this becomes possible only if the gametes are haploid.
What cells are formed as a result of mitosis? The answer is simple: diploid, that is, with a double chromosome set. This process is also important. The thing is that as a result of mitosis, cells are formed that are an exact copy of the mother ones. They are all somatic.
Mitosis phases
The process of formation of new somatic cells includes several phases. Their total duration, depending on the type of organism, ranges from a couple of minutes to several hours.
The initial stage is called prophase. At this time, the chromatin threads are compacted, the nucleoli are reduced, and the fission spindle is formed. The shell of the nucleus disintegrates, as a result of which the chromosomes enter the cytoplasm.
The second stage is called metaphase. Its essence lies in the construction of chromosomes in one planeand attaching spindle threads to them. This is followed by anaphase, which is the shortest stage. As a result of mitosis, fully formed daughter cells are formed. This process ends at the telophase stage. In this case, the chromosomes are despiralized. They are almost invisible under a light microscope. Further, the shell of the nucleus begins to form near the chromatids, and the division spindle gradually disappears.
How many cells are formed as a result of mitosis
Mitosis as a way of dividing eukaryotic cells is the most common in nature. The restoration of lost or damaged parts of the body occurs precisely through this process. As a result of mitosis, two daughter cells are formed from one parent cell. At the same time, due to the doubling of the DNA molecule in the interphase of the cell cycle, the diploid chromosome set is preserved.
Mitosis is the basis of all types of asexual reproduction: vegetative - in plants, cell division in two - in protozoa, multiple cleavage - in malarial plasmodium, sporulation - in fungi and ferns, budding - in coelenterates.
Biological significance of mitosis
As a result of mitosis, cells with the same chromosome set as the mother cells are formed. As a result, the process of transferring genetic information is ensured, no matter how many permanent divisions are carried out. During this process, both the number of chromosomes and the very sequence of nucleotides in DNA molecules remain constant.
SoThus, as a result of mitosis, two daughter cells are formed from one cell, which completely copy the original ones. This ensures the stability of karyotypes and is a prerequisite for the existence of all living organisms throughout the entire period of their individual and historical development.
