What are stem cells?
Stem cells are master cells of the body - cells from which all other cells with specialized functions are created.
Where do stem cells come from?
There are several sources of stem cells: embryonic stem cells, adult stem cells, adult cells altered to have the properties of embryonic stem cells and amniotic stem cells.
Why is there a controversy about using embryonic stem cells?
Embryonic stem cells are obtained from early- stage embryos. Extracting stem cells from embryos raises ethical and moral questions.
Where do the embryos come from?
The embryos that are used in embryonic stem cell research come from eggs that were fertilized at invitro clinics but never implanted in a woman's uterus.
Why don't researchers use adult stem cells instead?
Researchers believe that the adult stem cell may not be as versatile and durable as the embryonic stem cells are.
Have stem cells already been used to treat diseases?
Yes. Stem cell transplants also known as known as bone marrow transplants have been preformed in the US since the late 1960's. Stem cells from umbilical cord blood have been successfully used to treat rare genetic diseases.