Mitosis consists of four phases: prophase, metaphase, anaphase, telophase.
In prophase, chromosomes, consisting of two sister chromatids, spiral and thicken. In this form, they are clearly visible under the microscope. The cell center, located on the side of the nucleus, activates and begins to form microtubules, consisting of proteins. Fission poles arise, microtubules depart from them, the so-called dividing spindle yarns, which will further ensure the movement of chromatids. At the end of prophase, the nuclear membrane dissolves, and the chromosomes end up in the cytoplasm of the cell.
In metaphase, microtubules are attached to the centromeres of each chromatid. Chromosomes line up at the equator, forming a metaphase plate. The movement of microtubule proteins leads to the separation of chromatids of each chromosome and to their gradual pulling to the fission poles.
Anaphase is characterized by the fact that chromatids, as a result of shortening microtubules, move to the poles of cell division.
Telophase is the final stage of nuclear fission. Chromatids – the future chromosomes of daughter cells – are located at the fission poles, gradually lose their previous shape and become invisible in microscopy. The nucleolus is again formed, the nuclear membrane is formed. Mitosis ends.
Remember: The process of learning a person lasts a lifetime. The value of the same knowledge for different people may be different, it is determined by their individual characteristics and needs. Therefore, knowledge is always needed at any age and position.