How it works
A stem cell can make more of itself and can also become other kinds of cell. The first chart is a stem cell differentiation diagram, from one cell to specialized cells; the second shows adult and induced pluripotent stem cells.
Read the full guide
Read the first chart as a stem cell potency diagram
Potency is how many kinds of cell a cell can become. The first cell is totipotent: it can give rise to every cell type. It leads to the blastocyst, whose inner cell mass is the source of embryonic stem cells. Those are pluripotent: they can become any cell of the body. They give rise to three germ layers, and the cells of each layer differentiate into specialized cells. An adult stem cell, on the second chart, is multipotent: it makes only the cell types of its own tissue.
The induced pluripotent stem cells diagram
On the right of the second chart, an ordinary body cell is reprogrammed into a pluripotent stem cell.
- A curled arrow means self-renewal: the cell divides to make more cells like itself.
Questions and answers
What is the difference between totipotent, pluripotent and multipotent?
A totipotent cell can give rise to every cell type, including the tissues that support an embryo. A pluripotent cell can become any cell of the body. A multipotent cell can become several cell types, usually those of one tissue.
What is an induced pluripotent stem cell?
A pluripotent stem cell made in a laboratory from an ordinary body cell, such as a skin cell. Adding a few genes reprograms the cell into a state much like that of an embryonic stem cell. It was first done in 2006.
What are the three germ layers?
Ectoderm, mesoderm and endoderm. The ectoderm gives rise to the nervous system and skin, the mesoderm to muscle, bone and connective tissue, and the endoderm to the lungs and digestive organs.
What is an adult stem cell?
A stem cell found in a tissue or organ after birth. It renews itself and makes the specialized cells of that tissue. A blood stem cell, for example, gives rise to red and white blood cells.