Question

The eutherian placenta is derived from

• A. Yolk sac
• B. Amnion
• C. Allantois
• D. Chorion allantois

Answer 1

The correct option is D Chorion allantois

Eutherians are placental mammals. The chorion is the outermost embryonic membrane and lines the inside of the eggshell. Chorion forms the embryonic portion of the placenta. The allantois is the sac-like extraembryonic membrane, that removes the waste from the embryo. As the embryo grows, the placenta is formed by the fusion of the allantois and chorion.

So, the correct answer is option D.