Which structure is the organ where nutrients and oxygen are exchanged between mother and baby?

• A. Umbilical cord
• B. Amnion
• C. Placenta
• D. Chorion

Answer: (C)

The placenta is the organ that enables exchange of nutrients and oxygen between mother and fetus. It contains fetal vessels within chorionic villi that are surrounded by maternal blood in the intervillous spaces. Oxygen and nutrients diffuse from the mother's blood into the fetal blood, while waste products and carbon dioxide diffuse in the opposite direction. The fetus remains protected by a membrane barrier and does not have direct blood mixing. The umbilical cord simply transports blood between the fetus and the placenta, while the amnion and chorion are membranes that surround and contribute to the placenta’s structure but are not the sites of this exchange.