What is an Embryo?
An embryo is an organism in the early stages of development which cannot survive on its own. The precise definition of an embryo varies; in humans, for example, a fertilized egg may be considered an embryo until around the eighth week of pregnancy, at which point it is termed a fetus. The study of embryos is known as embryology, and it makes up part of a larger branch of science which is interested in reproduction and development. The term “embryo” is only used to refer to eukaryote organisms, otherwise known as multicellur organisms. Typically, people use the term specifically to refer to diploid eukaryotes, meaning that the embryo has a complete set of genetic material from two donors. This genetic material takes the form of haploid sperm and eggs; a haploid cell only contains half a set of chromosomes, meaning that it cannot develop into anything unless it is combined with another haploid cell. As an embryo matures, it starts to turn into a recognizable form, at which point people m
Though produced in a new and bizarre manner, a cloned embryo grows and develops as a living organism in the same way as one produced by fertilization. Writes Professor Lee Silver of Princeton University: “Cloned children will be full-fledged human beings, indistinguishable in biological terms from all other members of the species. Thus, the notion of a soulless clone has no basis in reality” (Remaking Eden: Cloning and Beyond in a Brave New World, New York: Avon Books 1997, p. 107). To claim that an embryo produced by cloning is not really an embryo, in order to justify destructive experimentation on it, is arbitrary and “self-serving” (Embryologist Jonathan Van Blerkom of University of Colorado, in American Medical News, Feb. 23, 1998, p. 32). Some proponents of destructive embryo research try to deny moral status to all early human embryos. They have coined the term “pre-embryo” to describe human embryos in the first two weeks of development, seeking to justify destructive experiment
