Which type of stem cell can produce any type of tissue but not an entire organism?

Pluripotent stem cells are unique in their ability to differentiate into almost any cell type within the three germ layers: ectoderm, mesoderm, and endoderm. This capability allows them to give rise to various tissues and organs within the body but does not extend to creating an entire organism, as they cannot form the extra-embryonic tissues such as the placenta.

In contrast, totipotent stem cells can give rise to all cell types including those necessary for embryonic development and extra-embryonic tissues, thus capable of producing a complete organism. Multipotent stem cells are more specialized and can only differentiate into a limited range of cell types within a particular lineage (for example, hematopoietic stem cells can develop into different types of blood cells). Unipotent stem cells have the least differentiation potential, being able to produce only one type of cell.

Therefore, the defining characteristic of pluripotent stem cells is their versatility in generating nearly all tissues in the body, but with the limitation of not being able to develop into a whole organism, distinctly setting them apart from totipotent stem cells.