A controversial issue, closely related to cloning, that has caused a lot of debate is the use of embryonic stem cells. One possible application of these cells is that they may be able to supply replacement tissues to treat diseases such as Parkinson's disease, diabetes, paralysis due to spinal cord injuries, and other degenerative diseases.
The word "embryonic", has caused fierce opposition to this type of research because embryos are destroyed when the stem cells are removed. Questions that have surfaced in this debate include: When a cell nucleus is transferred to another cell, have we created life? Does a stem cell have the same status as a human? What should be done with the embryos that are left over at in vitro fertilization (IVF), clinics? Advocates argue that the medical benefits of stem cell research would be enormous. Opponents argue that life begins at conception and thus this type of research is abortion.