The embryo is the name for a fertilized egg in its first eight weeks of its life. The embryo develops from an egg fertilized by the sperm. It begins as one cell, which divides into two cells by the times it descends from the fallopian tube into the uterus. These cells divide further until they form two groups - one making up the wall lining of the embryo to become the placenta, and the second becomingmycontentbreak the embryo itself.