Final answer:
Cell division is crucial for the development, maintenance, and repair of tissues in multicellular organisms, and is required for replacing damaged or worn-out cells. Different cell types need to be replaced at different rates based on their exposure to wear and their role in the body.
Step-by-step explanation:
Cell division is fundamental for the growth, maintenance, and repair of tissues in multicellular organisms. It is the process in which a single cell divides to produce two new daughter cells, ensuring the continuity of life and the functionality of an organism.
Different cells in the body have varying lifespans and are exposed to different stressors, thus they need to be replaced at different rates. For instance, epithelial cells in the skin and gastrointestinal lining divide frequently due to constant wear by friction or movement of food respectively. The cell cycle dictates when and how a cell prepares for and completes the division process.