In human embryos, the yolk sac is important because it
A) stores nitrogenous wastes.
B) allows for gas exchange through the placenta.
C) stores yolk.
D) gives rise to earliest blood cells and blood vessels.

Question

Quizplus · Accepted Answer

The yolk sac in human embryos is crucial for the formation of the earliest blood cells and blood vessels. It does not store yolk, as humans do not have yolk in their eggs.

In Human Embryos, the Yolk Sac Is Important Because It