Question: What is a stem cell?
Answer: Most cells in the body have specific characteristics and functions: skin cells, muscle cells, or blood cells, for example. All of these different types of cells develop from a generic type of cell called a stem cell. Stem cells divide slowly and wait for a signal to activate genes that will cause the cell to develop the physical and functional characteristics of a specific type of cell.
The stem cells found in the human embryo can develop into all of the different types of cells in the body, while adult stem cells (found in both adults and children) can develop into several different cell types. For example, hematopoietic (blood-forming) stem cells can develop into any type of blood cell, from white blood cells to erythrocytes, depending on what is needed most by the body.
