Final answer:
Pluripotent stem cells can differentiate into almost any cell type in the human body but cannot develop into a full organism. They derive from totipotent cells of the early embryo, and as development progresses, they specialize into multipotent cells with a more limited differentiation potential.
Step-by-step explanation:
Embryonic stem cells that are pluripotent have the remarkable capability to differentiate into almost any cell type within the human body. These cells originate from totipotent stem cells, which can give rise to every cell type necessary for the growth and development of an organism. However, pluripotent stem cells differ in that they can't support the entire development of an organism on their own. As development progresses, they specialize further into multipotent cells, which can only become a limited range of cells within a particular cell lineage, like blood cells.
The transition from totipotency occurs shortly after fertilization, as the zygote begins its first cell divisions. Only during the initial few days is the inner mass of cells totipotent. Thereafter, these cells commit to specific lineages as pluripotent stem cells, setting the stage for the development of the fundamental tissue layers of the embryo. Pluripotent cells can give rise to multiple cell types of the body and some supporting fetal membranes but are one step down from the totipotent cells found at the zygote stage.
In the laboratory, these cells can be induced to differentiate into specialized cells by altering the growth conditions. This manipulation of pluripotent stem cells, like human embryonic stem cells (hESCs), is a promising area for developing treatments for various diseases, and represents a significant aspect of regenerative medicine. However, the mechanisms governing cell specialization from non-differentiated states remain an active area of research.