This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Physiology
Biphasic action potential of mixed nerve except? 
Select and explain. 
A. All or none phenomenon, B. Two or more positive peaks, C. Refractory period, D. Recorded on surface
B: Two or more positive peaks
Answer: B: Two or more positive peaks 
Explanation: Ans. is'b'i.e., Two or more positive peaksAction potential when recorded by putting two electrodes on the surface of a neuron (instead of putting on surface and one intracellularly), shows a biphasic response, i.e. Biphasic action potential.As the wave of depolarization reached the first electrode, this electrode becomes negative and an upward deflection (Peak) is recorded.