Importance of Meiosis

Serena Cuoghi
Title of Professor of Biology

Among the multiple circumstances that make the existence of living beings possible, there is a microscopic process to which the genetic material that gives all the attributes to each species. A type of cell division specialized in the generation of the biological units necessary for the viability of a sexualized reproduction. This process, known as meiosis, has not only been one of the main drivers of the genetic variability existing between species, but also of the modeling of subtle differences in external appearance between members of the same species, which may have been considered as the characteristic distinctive features of a race or a group familiar.

Starting from the beginning, the generation of a mechanism by means of which not only individual cells, but the entire individual could reproduce, represented the great leap towards the possibility of the existence of multicellular organisms, solving all the inconveniences of the most primitive forms of cell division and individualized.

In order for this evolutionary cross to take effect, a series of attributes were then required to fulfill: 1) the production of cells containing only a portion of the genetic material of the species; 2) that said division be equitably distributed among the smallest possible number of members of the same species, in order to economize all available resources and reduce to a minimum the possibilities of random; 3) the generation of specialized organic structures for such a reproductive feat; 4) the biological distinction of reproductive cells that could combine with each other, to regroup all the complete genetic material again; and 5) a distribution of roles that would subject the least number of individuals involved to the vital risk that creating within themselves a complete new individual represents; thus generating the need for biologically differentiated donor males and receptor females and specialized to give meaning to meiosis and make possible the existence of descending generations due to their noble mating.

sexual conveniences

From this meiotic distribution of a species' genetic information, a cargo cell known as diploid, generates four haploid offspring, each with half that charge genetics. But so that the final intention could materialize through a new genetically complete being, males and females they must also have morphologically distinct haploid cells, allowing one to be found waiting for the other.

Meiosis then ended up representing at the evolutionary level a whole range of new complexities among living beings, and not just a mere different model of division. cell, since from this basic functional principle, it became the promoter of the existence of sexual reproduction of multicellular organisms and all the subsequent stratagems that males and females have to devise, to finally achieve that their gametes join their half genetic loads and assume later in the most species - and in one way or another - the responsibility of making the offspring survive, in the face of the adversities that the external environment can do to them cross.

Equal opportunities

The generation of haploid cells resulting from meiosis allows the increase in genetic variability within the same species, because it allows the incorporation and transmission of genes from different lineage origins and with potential mutations due to environmental variations, from members that have developed in different niches, thus also increasing the adaptive possibility of the species in the face of changes in the environment, which in turn translates into greater biological plasticity in the face of the environmental facts, increasing the migratory possibility of the species and the resistance of the species before the climatic and environmental changes of smaller scale that can face your step.

On the other hand, the differentiation between sexually different organs and organisms equalizes the possibility of participation opportunities in reproductive phenomena, so that later the factors of natural selection between tastes and colors are the ones that provide a mechanism of genetic discrimination for the union of the combinations genetically optimal, by means of which to guarantee a species that is increasingly better adapted and healthier, with the limitation of the reproduction of lesser individuals. advantaged, due to the rejection that members of the opposite gender may confront, thus fulfilling the maxim of the survival of the fittest, even in the sexual competitions.

Difference of the process by meiosis

The cells of prokaryotic organisms can reproduce in two different ways. In the conventional process, known by the name of mitosis, the daughter cells each present copies of the entire genetic material of the original cell. On the contrary, in the particular mechanism called meiosis, the genetic content is distributed among the daughter cells that result with only half of the original nuclear material. The importance of meiosis It resides in the fact that it is the resource by which the gametes that participate in sexual reproduction are produced.

Indeed, the usual somatic cells of all prokaryotic beings include, under normal conditions, genetic material that is duplicated, although not redundant. These cells are conventionally designated as diploid, which is often symbolized as 2n. In the process of meiosis, the participating cells undergo two consecutive cell divisions, after which four cellular elements are produced that include half of the initial genetic material. These final cells are called haploid and are referred to as 1n or n by convention.

In the context of prophase, the components of each of the pairs of chromosomes pair up to give rise to a recombination of their genetic content. In a subsequent stage, known as metaphase, the chromosomes resulting from this phenomenon are located in a flat central, to later migrate towards the cell poles in the stage called anaphase. Consequently, each of the cells originated during this succession of stages (collectively known as meiosis I) has half the genome of the original cell. in the later meiosis II, these haploid cells divide to give rise to new cellular elements, whose maturation end will give rise to eggs and sperm.

In addition to ensuring sexual reproduction, the importance of meiosis consists of ensuring genetic variability, since the process of recombination of the content Genetics allows offspring originating from gametes to retain much of their the characteristics of its ancestors, but giving the new individual an absolutely unique and distinctive profile. Unlike natural parthenogenesis or artificial cloning, in which reproduction arises from a new mitosis, meiosis produces specimens that are truly different from their parents, opening the possibility of new adaptations and relationships with the biological environment and, in the case of humans, with the psychological environment and social.

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.

de Torres Perez-Hidalgo, M. L. (1981). Chromosomal study of human meiosis. Complutense University of Madrid (Spain).

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

Marcel Ortega, M. (2016). Surveillance mechanisms in mammalian meiosis. Autonomous University of Barcelona,.

Rodriguez Gil, S. G., Solmi, L., & Rossi, F. (2022). Meiosis, where it all began.