In mitosis of a single cell, the nucleus
duplicates its genetic material (DNA) and divides into two identical daughter nuclei. This process occurs in multiple stages, including prophase, prometaphase, metaphase, anaphase, and telophase.
During prophase, the chromatin in the nucleus condenses and becomes visible as distinct chromosomes. The nuclear envelope also begins to break down, allowing the chromosomes to move freely in the cell.
In prometaphase, the chromosomes become more condensed, and spindle fibers form and attach themselves to the centromeres of each chromosome. These spindle fibers help in the separation of chromosomes during anaphase.
During metaphase, the chromosomes align themselves at the equator of the cell, known as the metaphase plate. This alignment ensures proper distribution of genetic material to the daughter cells.
In anaphase, the spindle fibers separate the sister chromatids of each chromosome and pull them towards opposite poles of the cell. This ensures that each daughter cell receives an identical set of chromosomes.
Finally, during telophase, the chromosomes reach the opposite poles of the cell, and a new nuclear envelope forms around each set of chromosomes. The chromosomes begin to decondense, and the cell undergoes cytokinesis, dividing into two daughter cells.
Overall, mitosis is crucial for growth, development, and tissue repair, as it ensures that each daughter cell receives an identical copy of the genetic material.