Mitosis consists of several phases, which are essential for the division of the chromosomes and the formation of new cells. The phases of mitosis are as follows:
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Prophase: During this phase, the chromosomes condense, and the nuclear envelope breaks down. The mitotic spindle, composed of microtubules, begins to form.
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Prometaphase: This phase involves the complete disintegration of the nuclear envelope, allowing the spindle fibers to interact with the chromosomes. The chromosomes become attached to the spindle fibers at their centromeres.
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Metaphase: In metaphase, the chromosomes align at the cells equator, known as the metaphase plate. The spindle fibers ensure that each chromatid is attached to a spindle fiber from opposite poles of the cell.
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Anaphase: Anaphase is characterized by the separation of sister chromatids. The spindle fibers pull the chromatids apart, and each chromatid is considered a separate chromosome.
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Telophase: During telophase, the separated chromosomes reach the opposite poles of the cell. The nuclear envelope re-forms around each set of chromosomes, and the chromosomes begin to decondense.
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Cytokinesis: This is the final stage of cell division, during which the cytoplasm divides, resulting in two distinct daughter cells.
While some sources mention four phases of mitosis (prophase, metaphase, anaphase, and telophase), others include a fifth phase, prometaphase, which is an intermediate stage between prophase and metaphase. The phases of mitosis are crucial for ensuring the accurate division of genetic material and the formation of genetically identical daughter cells.
