Importance of Mitosis

Serena Cuoghi
Title of Professor of Biology

The importance of mitosis lies in its cellular reproduction condition par excellence, characteristic of the vast majority of life forms that currently populate the Earth. At this point, it is essential to remember that the genetic material of cells can be organized in two different ways. On one hand, the prokaryotic organisms They are characterized by a single chromosome that is not enveloped in a nucleus. These cells (bacteria, some primitive algae) divide by simple fission. Instead, eukaryotic organisms (vegetables, including the others algae, fungus, protists, animals) store the genetic material of their cells in a subcellular structure called the nucleus. Within the nuclear interior, DNA (deoxyribonucleic acid) is arranged and "packaged" into an even number of chromosomes.

The course of evolutionary events required, at a certain moment in its origins, the implementation of an efficient mechanism that would allow first cells acquire the complex biological quality of reproducing, beyond the basic processes that prokaryotes had –and still have– to it. As the genetic material assumed a greater degree of complexity, its necessary replication also advanced towards a more assertive and efficient methodology, for means of which not only guarantee a faster mechanism for its coding, but also the incorporation of the possibility of generating "translation errors" during the process, a phenomenon that prompted the creation of genetic variability enjoyed by the thousands of different species that were able to evolve as consequence.

Process

During mitosis, the genetic material contained in the nucleus is arranged in such a way that each of the chromosomes is copied by specific enzymes to be distributed equally in each of the two daughter cells that will arise from this process. Therefore, mitosis It consists of a reproductive mechanism during which the entire DNA of a eukaryotic cell is copied to itself to give rise to new cellular elements.

The tissues with the highest proportion of mitosis are those that are characterized by rapid cell renewal or sustained and continuous growth. The embryonic tissues, all the epithelia (skin and mucosa of different organs) and most of the reproductive cells stand out in this regard. On the contrary, the most stable tissues are characterized by the absence of cell division and, therefore, mitosis. In this context, muscle cells and neurons of higher mammals, such as man, no longer perform mitosis.

It is worth distinguishing mitosis of the meiosis, which is another process of cellular division in which daughter cells are formed without prior duplication of chromosome material. Therefore, the new cells have half the chromosomes; This mechanism is what gives rise to eggs and sperm, that is, the reproductive cells. The fusion of these elements gives rise to a new organism that, from its first cell, is characterized by a complete, completely new and individual genetic material. Also, it is noted that mitosis It is a highly controlled and adjusted phenomenon to avoid alterations during cell reproduction. In neoplastic tissues, the process of mitosis loses this biological control and the cells reproduce in a accelerated and unregulated mode, which explains much of the behavior of cancer and other diseases associates.

divide to grow

The process of dividing the genetic material of the cells through mitosis also brought as a consequence the cellular capacity to form tissues, through the interconnection of contiguous cells, identical and specialized in some type of particular function, making the leap towards the constitution of complex organs, which in turn assumed different roles, but with a systemic correlation that allowed progress towards species more and more complex.

All this internal development of organisms has been used evolutionarily to give way to increasingly larger and more complex species, among which the variability Genetics reveals the importance that the environment has on the opportunities that determine the destiny of the survival of the species, as well as their coexistence between Yeah.

Evolution and variation

During the process of chromosome division managed by mitosis, there are many external factors that can influence it. From chemical substances with mutagenic potential unrelated to the process, such as organochlorine compounds, organophosphorus compounds or even heavy metals, to factors physical and energetic such as radiation or electromagnetic fields, going mainly through the stimuli that the environment imprints on each of the species as the main engine of evolutionary changes, in the face of a more than necessary adaptation, which has allowed the appearance of molecular modifications in the genetic code of ways both independent for each species, and those that are correlated between two or more species, thus establishing a coevolutionary character between the species. species.

A common example of this phenomenon is easily observable among some species, always belonging to the same niche and linked through their roles within the trophic chain, evidencing the existing game between prey and predators, with a wide range of adaptive deception possibilities, where the former have had the stimulus to transform their own genetics towards the development of both visual and chemical appearances, similar to those of their predators in order to keep as many members of their family safe as possible species, while the latter have been forced towards the evolution of their physical capacities to sharpen their senses and motor skills, so as not to starve for being left pass for fools

Mutagenic phenomena

Given the existence, then, of so many influential external elements on the results of the division mitotic, may well lead to justifiably questioning the efficiency of this reproduction mechanism cell phone. However, the ability to generate two identical daughter cells from one mother cell is not as fragile and vulnerable as it might seem.

The combination between the molecular change of the DNA structure and the viability of its success for the survival of the resulting cells after mitosis is another story. much more complex, because not every type of mutation can allow the normal performance of the modified cells, a fact that is actually much more frequent than it is could even be imagined or even traced, with silent systemic elimination of non-viable mutant cells usually occurring, while mutant cells can be demonstrate only through time, the results of those fortuitously successful feats of cells that managed to face a change and survive with their consequent contribution transmitted to the following generations of the same species, thanks to the divisions by mitosis that will continue to replicate the mutation as the new normal configuration in the generated cells.

References

Alberts, B., Bray, D., & Hopkin, K. (2006). Introduction to cell biology. Pan American Medical Ed.

Cardenas, O. (2013). Cellular and human biology. Ecoe Editions.

Lodish, H. (2005). Cellular and molecular biology. Pan American Medical Ed.

Mazia, d. (1961). Mitosis and the physiology of cell division. In the cell (pp. 77-412). Academic Press.

McIntosh, J. R., Molodtsov, M. I., & Ataullakhanov, F. YO. (2012). Biophysics of mitosis. Quarterly reviews of biophysics, 45(2), 147-207.