Answer:
Umbilical cords
Explanation:
The definition will be explained by the biological significance of stem cells and the potential to indefinitely self-renew while possessing a unique ability to differentiate into any type of cell tissue. After birth, the human umbilical cord is expelled from the womb and then discarded. Interestingly, extracting and using adult stem cells for biomedical applications prevents some of the ethically and biomedically questionable characteristics of using embryonic stem cells. For example, harvesting adult stem cells may not require embryo destruction.