Assertion: sponge's skeleton | /r/MadeOf | collagen
Facets:
Source sentences:
text: For example, bodily composition: the elastic skeletons of sponges are made from collagen, the same protein found in human tendons and skin.
text: For example, bodily composition: the elastic skeletons of sponges are made from collagen, the same protein found in human tendons and skin.