Final answer:
The generation of new cells to replace lost or to grow new tissue occurs by the process of cell division, which is crucial for growth, maintenance, and health in multicellular organisms.
Step-by-step explanation:
In some tissue types, the generation of new cells to replace cells that are lost or to grow new tissue occurs by the process of cell division. DNA replication is fundamental to this process as it ensures that each of the two new daughter cells has the full complement of DNA, mirroring that in the original cell. This process is vital for the growth, development, and maintenance of health in multicellular organisms like humans. Not all cells have the capacity to divide; however, for those that do, such as skin epithelial cells and some stem cells, frequent division is necessary to replace cells that are lost due to wear or to repair damaged tissues.
Furthermore, stem cell research is a promising field aiming to harness the ability of stem cells to regenerate and repair cellular damage, especially since most adult cells lose this capability over time due to aging. In plants, the equivalent ongoing growth and repair are facilitated by meristem, a plant tissue composed of undifferentiated cells that can divide and differentiate.