One of the points of the well-known theory of cell 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 critical to the process of reproducing oneself. 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 fragmentations or from the beginning of this process until 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 most important points is the process of doubling the DNA macromolecules. All genetic information about the cell is encrypted there.
How cell division occurs
With the help of meiosis, sperm and eggs multiply. 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 from germ cells, a new organism appears, containing half the hereditary information from the mother and father. And this becomes possible only if the gametes are haploid.
What cells form 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. All of them are 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 filaments become denser, the nucleoli decrease, and the fission spindle forms. The shell of the nucleus breaks up, due to the chromosomes fall into the cytoplasm.
The second stage is called metaphase. Its essence lies in the construction of chromosomes in one plane and the attachment to them of the threads of the fission spindle. What follows is 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 despiralize. They are almost invisible under a light microscope. Further, near the chromatids, the core shell begins to form, and the fission spindle gradually disappears.
How many cells are formed as a result of mitosis
Mitosis as a method of dividing eukaryotic cells is the most common in nature. The restoration of lost or damaged parts of the body occurs precisely thanks to this process. As a result of mitosis, two daughter cells from the same mother are formed. Moreover, 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 crushing - in malarial plasmodium, spore formation - in fungi and fern-like, budding - in intestinal.
The biological significance of mitosis
As a result of mitosis, cells with the same chromosome set as maternal cells are formed. As a result, the process of transmitting genetic information is ensured, no matter how many constant divisions are carried out. During this process, both the number of chromosomes and the sequence of nucleotides in DNA molecules remain constant.
Thus, 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.