Assertion: horseshoe crab's shell | /r/HasProperty | chitin
Facets:
Source sentences:
text: they are used in vision studies (their 10 eyes have a structure similar to the human eye); their blood protects them from infection and a compound it contains is used to detect bacterial poisons in some human medications; and a natural polymer found in the horseshoe crab’s shell (chitin) is used to make bandages.