What Does meiosis Mean
In the Greek it is where we can establish that the etymological origin of the term meiosis that now occupies us is found. Specifically, it emanates from the word “meíosis”, which can be translated as “decrease” and which is the result of the sum of two lexical components of that language:
-The comparative “meion”, which means “less”.
-The action suffix “-sis”.
Meiosis is called a form of reproduction of cells .
It is important to know that meiosis was discovered by the German biologist Oscar Hertwig (1849 - 1922). This one, in particular, came across it in 1876 and he did it while he was studying the eggs of a sea urchin.
After its discovery, and over the years, there were other scientists who were delving further into this form of reproduction, making new discoveries or leaving clear relevant nuances around it. This would be the case, for example, of the Belgian-born biologist Édouard van Beneden (1846 - 1910), who spoke of that in the Ascaris parasite, or of the American geneticist Thomas Hunt Morgan (1866 - 1945), winner of the Nobel Prize in Physiology. and Medicine in 1933. He focused his studies and research on meiosis on what is the fruit fly.
Meiosis implies that two cell divisions occur in the context of sexual reproduction. In this way, four cells are obtained with the number of chromosomes limited to half.
Specifically, meiosis allows a diploid cell (which has two sets of chromosomes) to divide twice consecutively, generating four haploid cells (with half the number of chromosomes each). This process of reproduction enables the creation of sperm and oocytes .
The first division is known as meiosis I , while the second is called meiosis II . In both, four phases can be distinguished : prophase , metaphase , anaphase and telophase .
It is important to know that the prophase in either case is the most complex phase of all those that shape meiosis.
It should not be forgotten either that if a correct separation of the so-called chromatids does not occur during anaphase, this can lead to problems such as trisomy.
In those organisms that reproduce sexually, haploid cell fusion takes place to form the diploid zygote. Therefore, meiosis is an instance prior to the development of gametes (sex cells).
It is important to note that these gametes are the only haploid cells of these species. The meiosis of certain cells gives rise to its appearance through the procedure called gametogenesis .
In short, meiosis causes a reduction to half of the number of chromosomes: from diploid cells (which, in humans , have 46 chromosomes), haploid cells (23 chromosomes) are obtained. Thus the number of chromosomes of the species is preserved at fertilization.