Final answer:
Adult human organs contain adult stem cells responsible for cell replacement and regeneration. These stem cells differentiate into specialized cells to repair tissue damage, and play a key role in regenerative medicine.
Step-by-step explanation:
Most adult human organs contain adult stem cells that are capable of cell replacement. Adult stem cells are a small subset of cells found in most tissues, and they have the remarkable ability to divide and differentiate. They can turn into a number of specialized cells that are generally formed by that tissue, thereby enabling the body to renew and repair body tissues. Adult stem cells are central to stem cell research, which seeks ways to harness their potential to regenerate and fix cellular damage associated with a range of diseases. Specifically in the heart and kidneys, where repair mechanisms are limited, stem cells offer hope for therapeutic applications. The ongoing research and development in the field could pave the way for creating organs in vitro from an individual's own cells, which would eliminate the risk of rejection when transplanted.