All living things have a cellular structure. Cells live: they grow, develop and divide. Their division can occur in various ways: during mitosis or meiosis. Both of these methods have the same division phases, preceding these processes, chromosome spiralization and independent doubling of DNA molecules in them occur. Let's consider what is the difference between mitosis and meiosis.
Mitosis is a universal method of indirect division of cells with a nucleus, that is, cells of animals, plants, fungi. The word "mitosis" comes from the Greek "mitos", which means "thread." It is also called vegetative propagation or cloning.
Meiosis is also a way of dividing similar cells, but the number of chromosomes during meiosis is halved. The origin of the name “meiosis” is based on the Greek word “meyesis”, that is, “decrease”.
The process of division during mitosis and meiosis
In the process of mitosis, each chromosome is split into two daughter chromosomes and is distributed over two newly formed cells. The life of the formed cells can develop in different ways: both can continue to divide, only one cell further divides, while the other loses this ability, both cells lose the ability to divide.
Meiosis consists of two divisions. In the first division, the number of chromosomes becomes two times less, two haploid cells are obtained from a diploid cell, while each chromosome has two chromatids. In the second division, the number of chromosomes does not decrease, only four cells with chromosomes are formed, each containing one chromatid.
Conjugation
In the process of meiosis in the first division, homologous chromosomes merge; during mitosis, any types of mating are absent.
Alignment
During mitosis, duplicated chromosomes are aligned separately along the equator, while in meiosis, a similar alignment occurs in pairs.
The result of the division process
As a result of mitosis, two somatic diploid cells are formed. The most important aspect of this process is that hereditary factors do not change during division.
The result of meiosis is the appearance of four sex haploid cells, the heredity of which is changed.
Reproduction
Meiosis occurs in maturing germ cells and is the basis of sexual reproduction.
Mitosis is the basis for asexual reproduction of somatic cells, and this is the only way of their self-restoration.
Biological significance
In the process of meiosis, a constant number of chromosomes is maintained and, in addition, new compounds of hereditary inclinations appear in chromosomes.
During mitosis, chromosomes are duplicated during their longitudinal cleavage, which are evenly distributed over daughter cells. The volume and quality of the original information does not change, and is fully preserved.
Mitosis is the basis for the individual development of all multicellular organisms.
Conclusions TheDifference.ru
- Mitosis and meiosis are ways of dividing cells containing a nucleus.
- Mitosis occurs in somatic cells, meiosis in reproductive cells.
- During mitosis, one cell division occurs, meiosis involves division in two stages.
- As a result of meiosis, the number of chromosomes decreases by 2 times, during mitosis - the preservation of the initial number of chromosomes in daughter cells.
