Given a scientific question, generate a correct answer to it.

Q: On the ventral side of the embryonic disc, opposite the amnion, cells in the lower layer of the embryonic disk (the hypoblast) extend into the blastocyst cavity and form this?

A: yolk sac
****
Q: Both fats and oils are made up of long chains of carbon atoms that are bonded together. what are these chains called?

A: fatty acids
****
Q: Living organisms release carbon dioxide into the atmosphere by what method?

A:
cellular respiration
****