Mitosis

Mitosis follows the G₂ phase and consists of four phases:

-prophase

-metaphase

-anaphase

-telophase

Mitosis is a cell division process that produces two daughter cells with the same chromosome number and DNA content as the original cell.

During prophase chromatin coils form chromosomes. The nuclear membrane and nucleolus start to disappears. The mitotic spindle apparatus begins to assembly between the centriole pairs. The two centriole pairs migrate to opposite poles of the cell.

During metaphase chromosomes becomes shorter, thicker and line up at the cell equator between the centriole pairs, and each chromosome has a centromere to which microtubules of the spindle apparatus attach.

During anaphase, which begins with the centromere region, the sister chromatids separate and move to opposite poles of the now elliptical cell along the mitotic spindle.

During telophase the chromosomes begin to uncoil. Telophase is marked by the reconstitution of a nuclear envelope around the chromosomes at each pole. The nucleoli reappear and the cytoplasm divides to form two daughter cells.

The daughter cells are 2n in DNA content and 2n in chromosome number.

Дата добавления: 2015-07-25