The Embryo

For the first eight weeks of its life, the fertilized egg is called the "embryo." 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 becoming the embryo itself.