The scientist stimulates the fused egg, which "activates" the egg and causes it to divide just as an egg would if it had been fertilized by a sperm cell in conventional reproduction. The activated egg is then placed in a culture medium. As cellular division continues over the course of several days, a blastocyst (early-stage embryo) forms. After about a week, an embryo transfer specialist transfers the blastocyst to a recipient female (sometimes referred to as "surrogate mother") where it continues to develop. After a full-term pregnancy, the recipient gives birth to an animal that is essentially the identical twin of the genetic donor.