Fill in all the gaps, then press "Check" to check your answers. Use the "Hint" button to get a free letter if an answer is giving you trouble. You can also click on the "[?]" button to get a clue. Note that you will lose points if you ask for hints or clues!

Extraembryonic membranes are
membranous that appear in
parallel the embryo and play
roles in the embryonic
. They form from the
but do not become of the
individual organism its birth.