Mitosis is a fundamental process of cell division that enables the growth, development, and repair of multicellular organisms. It consists of four distinct stages: prophase, metaphase, anaphase, and telophase. Each stage has specific events and characteristics that contribute to the accurate segregation of genetic material and the formation of two identical daughter cells.

Prophase:
During prophase, the nucleus undergoes profound changes in preparation for cell division. Key events include:

Chromosome Condensation: The chromatin fibers in the nucleus condense, forming visible chromosomes. Each chromosome consists of two identical sister chromatids held together by a structure called the centromere.
Nuclear Envelope Breakdown: The nuclear envelope, which separates the nucleus from the cytoplasm, disassembles. This allows access to the genetic material for subsequent processes.
Spindle Formation: Protein structures called microtubules form a spindle apparatus that spans the length of the cell. The spindle fibers attach to the chromosomes at their kinetochores, specialized protein structures on the centromeres.

Metaphase:
During metaphase, the condensed chromosomes align along the equatorial plane of the cell. Key events include:

Chromosome Alignment: The spindle fibers exert tension on the chromosomes, causing them to align at the metaphase plate, which is an imaginary plane equidistant from the two poles of the cell.
Spindle Fiber Attachment: Each sister chromatid is attached to a spindle fiber originating from opposite poles of the cell via its kinetochore.

Anaphase:
The anaphase stage is characterized by the separation and movement of sister chromatids towards opposite poles of the cell. Key events include:

Sister Chromatid Separation: The cohesion proteins holding the sister chromatids together are cleaved enzymatically. This allows each chromatid to become an individual chromosome.
Chromosome Movement: Motor proteins on the spindle fibers contract, pulling the separated chromosomes towards opposite poles of the cell. Non-kinetochore microtubules also elongate, contributing to cell elongation.

Telophase:
Telophase marks the final stage of mitosis when the nuclear division is completed, and two daughter nuclei begin to form. Key events include:

Nuclear Envelope Reformation: New nuclear envelopes develop around each set of chromosomes at opposite poles of the cell. These envelopes originate from fragments of the disassembled nuclear envelope from prophase.
Chromosome Decondensation: The chromosomes start to decondense, returning to their less condensed chromatin state.
Cytokinesis Initiation: Cytokinesis, or the division of cytoplasm, begins during late telophase or shortly after mitosis. In animal cells, a contractile ring composed of actin and myosin filaments forms at the equatorial plane and constricts, leading to cell membrane furrowing. In plant cells, a new cell wall forms between the two daughter nuclei.

Conclusion:
Mitosis is a complex process that ensures the accurate distribution of genetic material from a parent cell into two daughter cells. The stages of prophase, metaphase, anaphase, and telophase each play a crucial role in this process, facilitating chromosome condensation, alignment, separation, and formation of new nuclear envelopes. Understanding these stages is essential for comprehending cell division and its role in growth, development, and tissue repair in multicellular organisms.