What is a key characteristic of stem cells?

A key characteristic of stem cells is their ability to reproduce indefinitely, which is crucial for their role in growth, development, and tissue repair. Stem cells have the unique capacity to divide and give rise to multiple types of specialized cells, which is central to their function in the body. This limitless potential for division allows them to replenish other cell types as needed, making them invaluable in both natural processes and therapeutic applications.

Other options do not accurately represent the nature of stem cells. For instance, stem cells are not limited to one type of cell; rather, they can differentiate into multiple cell types depending on their environment and signals they receive. Additionally, stem cells can be derived from various sources, including embryonic stem cells and induced pluripotent stem cells, which means they are not restricted to only adult sources. Furthermore, stem cells are characterized by their undifferentiated state and have the potential to differentiate into specialized cell types; therefore, saying they are always differentiated contradicts their fundamental properties.