Mitosis is one of two types of cell division in eukaryotes. It is used to reproduce somatic cells, creating two new ones with identical sets of DNA from an old cell.
What is mitosis?
In mitosis, cell division occurs with the goal of reproducing two new, young cells with identical DNA sets from one aging cell. In mitosis, cell division occurs with the goal of reproducing two new, young cells with identical DNA sets from an aging cell. Mitosis happens in four stages, where first the DNA splits in the middle. The missing piece is reproduced, and two exactly identical DNA strands are contained in the cell nucleus. Then the cell itself splits into two new cells. The cell organelles are produced anew thanks to the DNA and there are two identical cells. Mitosis is the core component of body substance reproduction. Depending on the cell type, human cells have a life span of hours to days or weeks, after which they are old and must be replaced by new ones. Mitosis also happens in wound healing, where new body substance must also be built to replace the injured substance. Mitosis is to be distinguished from meiosis, in which reproductive cells are produced. Except for egg and sperm cells, cell division is always mitotic in nature, producing the initial cell in duplicate to replace aging body substance.
Function and purpose
Mitosis enables the reproduction of cells whose DNA set exactly matches the body cells already present. Thus, body substance of all types can be renewed, and the cell type from which mitosis originates is renewed identically. There are only a few exceptions of cells that are not created by classical mitosis, in which an identical new cell is created from an old one. Red blood cells, for example, die after their average lifespan and are replicated (mitotically) by the bone marrow. However, stem cells are present in the bone marrow. These are able to reproduce any cell type by mitosis, even if it does not perform exactly the same function as they do, including red blood cells. Muscle and nerve cells are formed in a similar way. All these cell types do not have their own nucleus, which is, however, a prerequisite for mitosis, since the nucleus contains the DNA. Mitotic division processes are particularly important in growing children. In this case, mitosis must not only replace aging cells, but also build up more body mass over the years. That is why a healthy diet is very important, especially for children, because with faster cell division than adults, they have a high demand due to their growth.
Diseases and ailments
Mitosis is a complex process that also poses dangers due to the splitting and reproduction of DNA. As vital as mitosis is, it is also the site where cancers originate. Due to radiation, chemical substances or other environmental influences that are capable of epigenetically influencing or altering the DNA or interrupting it in its division process, errors can occur in DNA cleavage during mitosis. A defective set of DNA is formed in one or two cells, these degenerate cells continue to divide and can develop at a very rapid rate. Benign or malignant tumors develop that either emit toxins themselves or put pressure on vital organs, which can be fatal. This serious type of error in mitosis is similar to errors in meiosis, which lead to defective reproductive cells and thus to congenital hereditary diseases. Mutations can occur due to shifts in DNA that are not harmful and occur naturally (e.g., crossing-over). These are “experiments” of nature, whereby, for example, in the animal world, different fur colors have arisen in the same animal species. For example, the white variant of the hare, the snow hare, tends to survive in cold regions of the earth, while the brown hare has better chances of survival in more southern latitudes – but without mutations, the different fur color would not have developed. Mutations occur continuously, but this only becomes apparent in the next generation. Mutations during mitosis result in various diseases or differences, which, however, do not always have to represent a disease.Because the DNA changes, the cell also produces other proteins. These proteins, in turn, are used as usual in the construction of new body substances and materials, but the usual product that the cell is actually responsible for producing is not created. One example is sickle cell anemia, in which the red blood cells take on a sickle-like shape. In malaria areas, this is an advantage because sickle cell anemia is associated with resistance to malaria. For northern Europeans, on the other hand, this mutation would be a disadvantage, because the sickle shape of the red blood cells means that not as much oxygen can be transported as with the normal shape. This example proves in humans how experimental mutations in mitosis can be and that they are proof of the existence of evolution – because what would be considered a disease in this country is a protection against a disease in other parts of the world.
