Reproductive cloning entails implanting a cloned embryo into a natural or artificial uterus. The embryo becomes a foetus, which is subsequently carried to term. For more than 40 years, reproductive cloning operations were carried out using the embryo splitting method, in which a single early-stage two-cell embryo is manually separated into two individual cells and then grows as two identical embryos. Following the birth of Dolly, who was created by the SCNT process, reproductive cloning techniques experienced substantial modification in the 1990s. Reproductive cloning is a technique for creating a clone or an identical replica of a multicellular creature. Most multicellular organisms reproduce sexually, which includes genetic hybridization of two individuals (parents), making an identical copy or clone of either parent impossible. Recent biotechnology advancements have made it possible to experimentally produce asexual reproduction in mammals in the laboratory.