The place where sperm is produced is the scrotum
set the fish in somewhere to rest it on and squeeze the liquid out of the fish, then put the liquid into a test tube and mix it with water, wait and then look at it.
I'm not sure if this question is talking about neurons, but if it is... depolarization in a neuron leads to an "action potential."
The functional groups determine the shapes of macromolecules and this in turn determines their functions