Both the amnion and chorion of a developing chick
A) are formed by ectoderm and endoderm.
B) secrete fluid that protects the embryo.
C) function in the exchange of respiratory gases.
D) are formed by ectoderm and mesoderm.
E) form before the yolk sac does.

Question

Quizplus · Accepted Answer

The amnion and chorion in a developing chick are both formed by ectoderm and mesoderm. The amnion is a membrane that encloses the amniotic fluid, providing a protective cushion for the embryo, while the chorion is involved in gas exchange and also contributes to the formation of the placenta in mammals. Both structures are derived from the ectoderm, the outermost germ layer, and the mesoderm, the middle germ layer, which is responsible for developing the circulatory system, muscles, skeletal system, and much of the excretory system.

Both the Amnion and Chorion of a Developing Chick