Cloning is asexual reproduction in which an exact genetic copy of another plant, animal or human is made by fusing the DNA from an adult cell into a human egg from which the genetic material has been removed, causing it to divide and grow. By definition of the National Academy of Sciences, a clone is an exact genetic replica of another organism.
The development of human cloning will require the deliberate sacrifice of human embryos. This use of human life merely as a means to an end is morally unacceptable. There are also scientific reasons to oppose human cloning, such as the potential for mutation, transmission of mitochondrial diseases and the negative effects from the aging genetic material. In addition, societal reasons to be hesitant about include questions about parentage, lineage, family structure and the uniqueness of the individual.