Which embryonic structure contributes directly to the mammalian placenta?
A) Yolk sac
B) Chorion
C) Uterus
D) Amnion
E) Blastocoel

Question

Quizplus · Accepted Answer

The chorion is a membrane that originates from the trophoblast (the outer layer of the blastocyst) and contributes directly to the development of the placenta in mammals. The yolk sac, amnion, and blastocoel are also embryonic structures, but they do not directly contribute to the placenta. The uterus is not an embryonic structure, but rather a maternal organ that provides the environment for embryonic development.

Which Embryonic Structure Contributes Directly to the Mammalian Placenta