A good book to read is "Body Electric" by Dr. Robert O. Becker, M.D. in which he explains in plain and simple terms the various roles that electricity plays in life and living organisms.
He explains many things that are purely fascinating such as how salamanders can regrow a new arm but many other vertebrates such as humans can not regrow even a finger. He also explains how humans might be fooled into regrowing certain parts of the body.