Answer:
4) It allows the exchange of nutrients between the embryo and the mother, while at the same time filtering out harmful material.
Step-by-step explanation:
The placenta is an organ present in all mammals. She is confirmed between the 6th and 8th week of pregnancy and has as main function the exchange of substances between the mother and the fetus. Among these substances are nutrients, gases and even secretions. The placenta also has the function of fighting infections and promoting immunity to the fetus, in addition, it can act as the lung, the intestine and the liver, while the fetus does not develop its organs.