Which structure is responsible for nutrient exchange between the mother and developing embryo?

The placenta is the correct choice because it serves as the primary structure through which nutrient exchange occurs between the mother and the developing embryo. This organ forms during pregnancy and is crucial for transferring oxygen, nutrients, and waste products between maternal blood and the fetal circulatory system.

The placenta is vascularized, meaning it has a rich blood supply, which allows it to efficiently facilitate these exchanges. It also plays a key role in hormone production, immunological protection, and waste removal, further supporting the developing embryo.

The other options do not fulfill the same role as the placenta. The uterus is the site where the embryo implants and grows but does not directly handle nutrient exchange. The amniotic sac provides protection and cushioning for the embryo but does not serve in nutrient transport. The Fallopian tube is where fertilization typically occurs, but it does not play a role in nutrient exchange throughout the pregnancy. Each of these structures has its own important functions, but the placenta is uniquely specialized for the critical task of facilitating the exchange of nutrients and waste products.