What does the prefix trop mean?

This is a biological reaction due to a stimulus. i need this quickly !

Tom wants to conduct a scientific study but he needs to finish by the end of the school year. what practical way could tom work around this limitation and be successful in his study?

Brendan made a diagram to compare and contrast the benefits of two types of social behavior. which description belongs in the area marked "z"? reproductionprotectionforaginghydrodynamic efficiency