An animal has many legs, a very hard exoskeleton, and lives underwater. it is most likely

a an insect
b an arachnid
c a crustacean
d a sponge

On a floor there are several 1-4 mm elongated drops leading away from a body lying in a pool of blood. the the forward wall there is a sigzag pattern and on the walls to the right side there is a linear patter

Penelope studies how the structure and function of the nervous system is related to behavior. she is a psychologist

The arrows in the illustration point to