Detailed Summary
The M phase, or mitosis phase, of the cell cycle marks the period during which the actual division of a cell occurs. This phase is integral to the lifecycle of cells, ensuring that each daughter cell receives a complete set of chromosomes. The M phase can be broken down into several key stages:
- Prophase: Chromosomal material condenses and becomes visible, centrosomes move to opposite poles, and the mitotic spindle begins to form.
- Metaphase: Chromosomes align at the metaphase plate with spindle fibers attached to kinetochores, which are disc-shaped structures at the centromeres.
- Anaphase: Sister chromatids separate and are pulled toward opposite poles of the cell.
- Telophase: Chromosomes de-condense, nuclear envelopes reform around each set of chromosomes, and nucleoli reestablish.
- Cytokinesis: The cytoplasm divides, resulting in two distinct daughter cells, with mechanisms differing between plant and animal cells.
Understanding the significance of the M phase is crucial for grasping how cells maintain genetic fidelity throughout the cycles of growth and division.