The structure that forms during the third week of development, as a tube extending from the early yolk sac into the connecting stalk of the embryo, is the:
A) chorion.
B) lacunae.
C) amnion.
D) allantois.
E) decidua.

Question

Quizplus · Accepted Answer

The allantois forms during the third week of development as a tube extending from the early yolk sac into the connecting stalk of the embryo. It plays a role in early fluid exchange between the embryo and the yolk sac.

The Structure That Forms During the Third Week of Development