5. Embryo to Fetus fifteen days twenty-one days thirty days thirty-four days six wks eight wks Life: One Seed + One Egg Life begins when an egg, previously released from one of the two ovaries, merges with just one of the hundreds of millions of sperm cells supplied through the vagina by the male reproductive system. The fertilized egg then descends to the wall of the uterus, where it implants itself to begin gestation .
