Alpha, beta, gamma and delta "waves" are not strictly waves, but are bands of the frequency spectrum of the EEG. Different cognitive states (such as attention or sleep) tend to be associated with different proportions of power in the different EEG bands. I think the current thinking is that...
What were the questions?
I'm curious because I teach on a UK psychology degree programme, and I don't believe the A/AS syllabus matches up very well with most BA/BSc programmes.
This may be the wrong way to think about an axon. The membrane of the axon contains ion channels that actively pump ions inwards and outwards across the membrane to change (or restore, or maintain) the potential. So it's not accurate to say that the membrane is an insulator since the "resting"...