Human Embyro Cells

Research has been conducted on patients with Parkinson's Disease using fetal brain cells. Swedish workers have demonstrated that patients receiving human brain cell transplants do produce dopamine and that the hole in the brain is plugged up. But where will this tissue come from?

• Should medical doctors be allowed to use tissue from aborted fetuses? After all, all the tissues in your body come from one fertilized egg. And, it would be easy to clone human embryos to obtain cell lines.
• Should medical doctors be allowed to use tissue from frozen embryos that will not be used for reproductive purposes?
• If human embryonic stem cells are removed from an early developing embryo would this be unethical because these cells cannot survive in the uterus nor will they implant into the uterine lining, that is, they can not survive on their own?