the embryonic stem cells are found within the what
Broadly speaking, two types of stem cell can be distinguished: embryonic stem (ES) cells which can only be derived from preâimplantation embryos and have a proven ability to form cells of all tissues of the adult organism (termed âpluripotentâ), and âadultâ stem cells, which are found in a variety of tissues in the fetus and after birth and are, under normal conditions, more specialized (âmultipotentâ) with an important function in tissue replacement and repair.