1. IB2.29.6 Stem cell research © Oxford University Press 2011 Stem cell research

2. IB2.29.6 Stem cell research © Oxford University Press 2011 What are they and where are they? Stem cells are undifferentiated cells. They are the forerunner to every kind of cell in the human body. They are useful in medical research and treatments because they can develop into many different kinds of cell. Doctors can get stem cells from:  early embryos  umbilical cord blood cells  some types of adult tissues, such as bone marrow  and, more recently, from amniotic fluid.

3. IB2.29.6 Stem cell research © Oxford University Press 2011 What are they used for? Medical research is developing ways of using stem cells to:  treat people with Parkinson’s disease  repair spinal cord injuries  grow tissues or organs for transplanting  treat people with type 1 diabetes.

4. IB2.29.6 Stem cell research © Oxford University Press 2011 Embryonic stem cells  Early embryo cells are the most useful because they still are able to differentiate into any type of human cell (of which there are 220). Scientists can do this by giving the stem cells an appropriate chemical signal.  Single cells taken from spare embryos created during IVF are used as stem cells to develop into, for example, nerve cells, blood cells and muscle cells.  Scientists can, however, now take one cell from an eight-cell embryo and use that cell to grow more stem cells. The remaining seven-cell embryo can develop normally into a baby.

5. IB2.29.6 Stem cell research © Oxford University Press 2011 Ethical issues Some people argue that embryonic stem cell development is ethically wrong as the spare embryos are not allowed to develop into people. However, even without stem cell research, these embryos would still be discarded. Using the stem cells may lead to people with spinal cord injuries being able walk again.