What replaces the membranes and nutrition source of amniotic eggs in organisms that exhibit live birth without amniotic eggs?

Question

Quizplus · Accepted Answer

The placenta replaces the role of the membranes and nutrition source of amniotic eggs in organisms that exhibit live birth. The placenta provides nutrients and oxygen to the developing embryo, removes wastes, and allows for gas exchange, similar to the yolk sac and allantois in amniotic eggs. However, unlike amniotic eggs, the placenta is attached to the uterus of the mother, providing a constant supply of nutrients and waste removal until birth. The amnion and chorion are also part of the amniotic egg structure and are not present in live birth organisms.

What Replaces the Membranes and Nutrition Source of Amniotic Eggs