Somatic cells in comparison with other cell types

"Soma" means the body, that is, in theory, any cell of our body should be called somatic. However, the directories give a different definition. In fact, there are a majority of somatic cells in the body, but there are other species in the body.

First of all, the non-somatic are the cells, which later turn into embryos. They share in a special way, uncharacteristic for somatic cells (meiosis), and have some other features. More recently, scientists have discovered a new class of cells that can not be called sexual or somatic. They are called stem cells, and any cell of the body can turn out of them.

Somatic cells of vertebrates form bones, internal organs, skin, blood and connective tissues. And the sex cells become spermatozoa and eggs. Unlike sex cells, somatic cells have a double set of special structures that provide heredity - chromosomes.

All somatic cells carry a legacy from two organisms, one half of the chromosomes is almost identical to the chromosomes of the mother of our individual, and the second - to the chromosomes of the father. We have used the word "almost" because each organism undergoes mutation processes throughout life, that is, unplanned and unfounded in the genes of changes. Mutations of somatic cells are not as serious as mutations of the genital. Because in the latter case the whole new organism will bear the traces of changes (they are in most cases undesirable for the organism, useful mutations are a huge rarity).

In general, somatic cells do not always have only two sets of chromosomes. Plants can have as many as four or six pairs of sets. The corresponding sex cells have 2-3 sets, which is understandable. For example, in wheat they can be four or six (depending on the species). In some cases, animal somatic cells also have more than two sets, for example, in salmon and salamander.

Sometimes too many sets of chromosomes (polyploidy) can occur in humans, this may be a consequence of a disturbance in the process of mitosis or the first phase of meiosis. In the first case, it's not scary - after all, only a few abnormal somatic cells are obtained, but if the sexual cell becomes a polyploid, then it is doomed, because very serious violations of the whole organism are inevitable when fertilization (if the cell has formed a zygote, the embryo will die) . All the same, polyploidy is not normal for higher species.

Sometimes polyploidy, which is not normal in some species (more often plants), appears after the use of certain chemicals, which is an additional argument for toughening environmental control.

The division of somatic cells creates cells that are identical to the mother cells, if the process has occurred normally and there are no disturbances provoked by external and internal factors. The process of dividing such cells is called mitosis and has long been studied by scientists. Such division is stable and reliable, but on the whole mitosis does not give any progress - the cells after all are obtained exactly as the cell that gave birth to them. But sex meets with the cells of another organism and form completely new cells that will become a unique organism and continue the evolutionary struggle.

Are there ways to get a whole organism that would not differ from the parent genetically? Yes, it's called cloning. The technique is simple theoretically - take the core of the somatic cell and place it in the egg instead of the "native" nucleus. Such an ovum does not need to be fertilized and it is possible to attach a female to the uterus. However, the technology is imperfect, in addition, the resulting organism is obtained by the patient and can not live long. So it's not in vain to forbid human cloning.

Thus, somatic cells constitute the largest part of our body, are divided by mitosis and have two chromosomal kits. This is the main thing you need to know about this variety of cells.