What is homogametic sex?

The cell of the human body has its own life cycle. In addition, she is able to multiply, using division. In the process of division, new cells are obtained that allow our skin to stretch during growth and not tear, maintain its color and be elastic. With age, division does not become so intense, so people get wrinkles, the skin becomes more decrepit, loses its color and elasticity. What cells are and what the homogametic sex of the child depends on at the stage of his birth, what are the positions of the science of heredity and more, we will consider below.

Types of cells and their life cycle

In our body there are many different organs that somehow support our vital functions. As you know, they all consist of cells, which, in turn, are divided into two types:

1. Somatic. These are the cells of our body, they multiply by Bespalov division, that is, in the process of mitosis. Somatic cells have a diploid set of chromosomes.
2. Sexual These cells are distinguished by gender. The male is called sperm, sperm, and the female is called the egg. They have a haploid set of chromosomes, that is, a single one. They multiply in the process of meiosis and determine the homogametic and heterogametic sex.

The life cycle of a cell, or, as it is also called, the cell cycle, is the period from the moment a cell appears to its division or death. Division is a complex process that is divided into two periods.

Mitotic cycle

Somatic cell division occurs in the mitotic cycle. It is divided into two phases:

1. Interphase Three periods of division occur in it. The first is presynthetic (in this period the cell grows, develops, accumulates nutrients, and performs its functions). The second is synthetic (at this stage, the cell doubles the DNA and chromosomes). The last period in the interphase is postsynthetic (at this period, the cell doubles its organs, accumulates energy, prepares for division and ATP is stored).
2. Mitosis. This process is divided into phases. The first is prophase (in this phase, the chromosomes are speralized and shortened, the nuclear membranes and nucleoli disappear, the cell center of the fission spindle is formed, then the chromosomes attach centers to the threads of the fission spindle). The next stage is metaphase (here the chromosomes line up horizontally at the equator). Then comes anaphase (daughter chromosomes, or, as they are also called, sister chromosomes, diverge to the poles). And finally, the fourth is the telophase (here the chromosomes unwind, the fission spindle is destroyed, the nucleoli and nuclear membranes appear, and the cytoplasm is divided).

This cell division does not affect homogametic sex.

Meiotic cell division

As in the mitotic cycle, meiotic division begins with interphase. She in this division is no different from the previous one. After interphase, there is a process called meiosis. Meiosis occurs in 2 divisions. It lays down information about whether the child will have a female homogametic sex.

The first division is called reduction, prophase occurs in it, as in mitosis, but conjugation and crossingover are added. Next comes the metaphase (homologous chromosomes line up at the equator), then the anaphase (homologous chromosomes diverge to the poles) and the final one is the telophase, which proceeds exactly as in mitosis.

Theory of Heredity

Heredity is a science that has helped a person understand why and how a child has signs of a parent. These signs can be very different, for example, character, body parts, diseases, etc., and most importantly, homogametic sex. For the theory of heredity, special provisions have been developed that prove the theory itself:

1. Genes on the chromosome are linear, forming a linkage group.
2. The number of linkage groups is determined by the haploid set of chromosomes.
3. Genes located on the same chromosome are linked, inherited together. The crossover process can break the grip.
4. The distance between the genes is determined by the morgonoids. 1 morgonoid = 1%.
5. The most important condition for heredity is that the farther away the genes are from the chromosome, the greater the probability of crossing over.

Gender inheritance

Sex plays a big role in our lives. No one can know in advance whether a boy or girl will be born, because it is determined by the chromosomes that begin to divide at the stage of meiosis. As stated earlier, gender inheritance is dependent on chromosomes. They are of two types:

1. Autosomes (identical chromosomes)
2. Sex chromosomes, on which the future sex of a person actually depends. They are divided into homogametic, that is, such chromosomes are the same, and heterogametic, that is, with a different set of genes.

Gender depends on which set was obtained during the division of germ cells. An example of a homogametic sex is women whose chromosomes have the appearance of XX. In men - XY. From all that was described in this article, we can conclude that the homogametic sex is the sex obtained during cell division in the mitotic phase.