Biology: Extraembryonic Membranes

To provide protection and nourishment for the embryo, as well as help with respiration and excretion.

Amnion, Chorion, Yolk sac, and Allantois.

To surround the embryonic body and provide an aquatic environment for development.

<p>Around 30 hours.</p> Signup and view all the answers

<p>To provide an avascular respiratory surface.</p> Signup and view all the answers

<p>Two limbs, an outer and an inner, both consisting of ectoderm and a thin layer of somatic mesoderm.</p> Signup and view all the answers

<p>A crescentic fold that projects over the head of the embryo as a double-walled cap.</p> Signup and view all the answers

<p>They originated in reptiles and passed on to aves and mammals.</p> Signup and view all the answers