M phases, also known as mitotic phases, refer to the stages in the cell cycle where cell division occurs. The cell cycle is a series of events that take place in a cell leading to its division into two daughter cells. M phases play a crucial role in the growth, development, and reproduction of multicellular organisms.
The M phases consist of two main stages: mitosis and cytokinesis. Mitosis involves the division of the nucleus, while cytokinesis involves the division of the cytoplasm.
During mitosis, the replicated chromosomes align at the center of the cell and separate into two identical sets, forming two separate nuclei. This stage is further divided into four sub-phases: prophase, metaphase, anaphase, and telophase. Each sub-phase carries out specific functions, such as the condensation of chromosomes, their alignment at the cell equator, their separation to opposite poles, and the formation of two daughter nuclei, respectively.
After mitosis, cytokinesis takes place, where the cell divides into two daughter cells. In animal cells, a contractile ring forms around the cell equator and gradually constricts, dividing the cytoplasm into two. In plant cells, a cell plate is formed in the center, which eventually develops into a new cell wall, separating the two daughter cells.
The M phases are tightly regulated by various cellular factors and checkpoints to ensure accurate cell division and genetic stability. Any disruptions or abnormalities during these phases can lead to cell death, genomic instability, or diseases such as cancer.
