Step 2 in the accompanying figure is accomplished by an influx of:

Step 2 in the accompanying figure is accomplished by an influx of:
  a. Ca2+
  b. Na2+
  c. K+
  d. Na2+
  e. K+

Question 2

What did Alan Hodgkin and Andrew Huxley conclude from their squid axon experiments?
  a. The passage of Na+ ions into a neuron and K+ ions out of a neuron results in an action potential.
  b. The passage of K+ ions into a neuron and Na+ ions out of a neuron results in an action potential.
  c. The passage of K+ ions into a neuron and Ca+ ions out of a neuron results in an action potential.
  d. The passage of Cl- ions into a neuron and K+ ions out of a neuron results in an action potential.
  e. The passage of Cl- ions into a neuron and Ca+ ions out of a neuron results in an action potential