'(Sarah of the Clue Crew in Cape Cod)  Baleen, which certain whales have instead of teeth, is composed of mainly this protein, just like hair & fingernails'
keratin
A WHALE OF A CATEGORY: Baleen, which certain whales have instead of teeth, is composed of mainly this protein, just like hair & fingernails
Baleen, which certain whales have instead of teeth, is composed of mainly this protein, just like hair & fingernails
Baleen, which certain whales have instead of teeth, is composed of mainly this protein, just like hair & fingernails
A WHALE OF A CATEGORY
keratin
A WHALE OF A CATEGORY