well as otherproteins, called enzymes, that could be used to speed up industrial chemical reactions. These genetically altered animals are typically used to produce human hormones orproteins in its milk. These materials can be separated from the milk and used to healhumans. Cloning would produce as many genetically altered animals as are needed. Thealternative is to simply allow them to mate; this would produce many offspring that hadlost the inserted human gene and thus would be unable to produce the medication. Researchers involved in cloning envision a number of other practical applicationsfor their work, including the creation of genetically modified animals that could provideorgans for human organ transplants: scientists are attempting to create transgenic animalswhich have human genes. Their heart, liver or kidneys might be usable as organtransplants in humans. This would save many lives; thousands of people die each yearwaiting for available human organs. Once achieved, transgenic animals could be clonedto produce as many organs as are needed. .Also through these experiments experience isgained in cloning, and it may add to our understanding of genetics and help in thecreation of these transgenic animals, especially the perpetuation of those animals that areendangered or already extinct.Some scientists believe that embryo cloning and related research is moral andmight eventually lead to very positive results: It might allow many homosexual couples, including men, to have a child geneticallysimilar to their them. Just as women have long been able to have children without amale sexual partner, through artificial insemination, men could potentially becomedads alone: replace the DNA from a donor egg with one's own and then recruit asurrogate mother to carry the child. Some gay-rights advocates even argue that shouldsexual preference prove to have a biological basis, and should genetic screening leadto terminations of gay embryos, ...