Which stem cells have the ability to form an entire organism?

Totipotent stem cells have the unique ability to form an entire organism. This type of stem cell can give rise to all cell types in an organism, including both the embryonic tissues and the extra-embryonic tissues such as the placenta. During early development, the zygote and the first few divisions of the cells formed are considered totipotent because they can differentiate into any cell type necessary to develop a complete and functional organism.

In contrast, pluripotent stem cells, while they can differentiate into nearly all cell types of the body, cannot develop into a whole organism on their own, as they lack the ability to form extra-embryonic tissues. Multipotent stem cells possess a more limited differentiation potential, typically differentiating into a particular lineage of related cell types. Oligopotent stem cells are even more restricted, able to generate only a few different types of cells. Thus, totipotent stem cells stand out due to their capacity to form an entire organism, which distinguishes them from the other types of stem cells mentioned.