The relative concentration of solute inside and outside a cell can cause water molecules to move across the membrane. Which phrase would be an alternative title to the diagram A. Facilitated Diffusion Across a Membrane
B. Osmosis Across a Membrane
C. Exocytosis in a Cell
D. Active transport in a cell

the answer that best describes the relative refractory period in the neuron is the resting membrane potential is restored, but concentrations of sodium and potassium are not restored to their original state.

the refractory period is the time during which another stimulus given to the neuron will not lead to a second potential. thus, because na+ channels are inactivated during this time, additional depolarizing stimuli do not lead to new action potentials.  

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