What type of stem cell is characterized by its ability to develop into all cell types of an adult organism?

Embryonic stem cells are indeed characterized by their ability to differentiate into all cell types of an adult organism. They are derived from the inner cell mass of a blastocyst, an early-stage embryo, and possess the unique ability to give rise to any cell type, including the various tissues and organs of an adult body. This pluripotent nature allows embryonic stem cells to play a crucial role in developmental biology and regenerative medicine, as they can potentially be used to replace or repair damaged tissues.

In contrast, other types of stem cells have more limited differentiation potentials. Adult stem cells are typically multipotent, which means they can develop into a limited range of cell types corresponding to their tissue of origin. Induced pluripotent stem cells, while also pluripotent like embryonic stem cells, are genetically reprogrammed adult cells rather than having the inherent pluripotency of embryonic stem cells. Totipotent stem cells can give rise to any cell type including placental cells, but they are only present in the very early stages of development, specifically the zygote and the first few divisions thereafter. Thus, the defining feature of embryonic stem cells is their broad capability to differentiate into virtually any cell type in the adult organism.