How Human Cloning Will Work

­At the outset of the clone craze, some scientists and companies focused on exploiting the science-fiction aspects of the technology. For instance, Zavos and Antinori, mentioned earlier, aimed to develop cloning to aid infertile couples -- to the tune of approximately $50,000 for the service. The group said that the procedure would involve injecting cells from an infertile male into an egg, which would be inserted into the female's uterus. This child would look the same as his or her father. Then there's the possibility of bringing deceased relatives back to life. A now-defunct company called Genetics Savings & Clone performed this type of cloning for a woman's dead cat, Little Nicky, in 2004.

­Therapeutic cloning holds the most promise of valuable medical advancement. Therapeutic cloning is the process by which a person's DNA is used to grow an embryonic clone. However, instead of inserting this embryo into a surrogate mother, its cells are used to grow stem cells. These stem cells could become the basis for customized human repair kits. They can grow replacement organs, such as hearts, livers and skin. They can also be used to grow neurons to cure those who suffer from Alzheimer's, Parkinson's or Rett syndrome. And since the stem cells would come from embryo clones using your own cell's DNA, your body would readily accept them. For more detailed information on stem cells, you can read How Stem Cells Work.

Here's how therapeutic cloning works:

To clone human embryos, however, you need eggs. If therapeutic cloning were to begin in earnest, it could increase the demand for such eggs and potentially create additional moral questions regarding the donors [source: Lamb]. Speaking of ethics, there's plenty of related debate to go around when it comes to human cloning.