Cells divide primarily for three main reasons: to enable an organism to grow, to replace damaged or dying cells, and to allow reproduction. Cells have a size limit because the plasma membrane must efficiently transport nutrients and oxygen to the inside of the cell via diffusion, which is more effective over short distances. If a cell grows too large, diffusion slows down and the cell cannot get sufficient nutrients or eliminate wastes effectively, so instead, cells divide to maintain efficient functioning and support the organism's growth.
During cell division, a parent cell duplicates its contents, including its chromosomes, and splits into two genetically identical daughter cells. This process ensures genetic consistency so that each daughter cell has the same information as the parent cell. Cell division also plays a vital role in healing wounds and renewing tissues, such as skin.
In unicellular organisms, cell division is a form of reproduction, producing two separate organisms from one cell. In multicellular organisms, it creates cells that contribute to the organism's body, growth, and repair. Moreover, cell division follows a regulated cycle with stages to ensure correct duplication and separation of genetic material, preventing errors that could lead to diseases like cancer.
In summary, cells divide to facilitate organism growth, tissue repair, and reproduction, while maintaining cellular efficiency and genetic fidelity across generations of cells.
