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

Input: Consider Input: What contains more calcium than any other organ?

Output: bones

Input: Consider Input: Name the fever that is caused by a virus that has antigens similar to molecules in human heart tissues.

Output: rheumatic fever

Input: Consider Input: Composed largely of the polysaccharide chitin, the exoskeleton provides an effective barrier defense against most what?
Output: pathogens