Which of the following human extraembryonic membranes is the first site of blood cell formation and the source of germ cells?
A) amnion
B) yolk sac
C) chorion
D) allantois
E) none of these

Question

Quizplus · Accepted Answer

The yolk sac is the first site of blood cell formation and is also the source of germ cells. The amnion is the innermost membrane that encloses the embryo and contains amniotic fluid. The chorion is the outermost membrane that contributes to the formation of the placenta. The allantois is important for gas exchange and waste removal, but does not play a role in blood cell formation or germ cell development in humans.

Which of the Following Human Extraembryonic Membranes Is the First