Answer:
Step-by-step explanation:
the egg is fertilized by a sperm as it travels down the fallopian tube, then pregnancy occurs. The fertilized egg attaches to the lining of the uterus. The placenta then develops. The placenta transfers nutrition and oxygen to the fetus from mother. If the egg does not become fertilized, the lining of the uterus (endometrium) is shed during menstruation.