Correct option is C
Explanation-
Statement A: "Much higher number of ions traverse a unit length of an MNF membrane compared to that of an NNF during conduction of action potential as the ionic currents are restricted to the membrane at the Nodes of Ranvier" - INCORRECT
In MNFs, ionic movement occurs only at the Nodes of Ranvier due to saltatory conduction. This reduces the number of ions moving across the membrane per unit length, not increases it, unlike NNFs where ion exchange occurs along the entire membrane.
Statement B: "The energy expenditure required to maintain ionic gradient after conduction of action potential in an MNF is higher than that of an NNF " - INCORRECT
Because fewer Na⁺/K⁺ exchanges happen in MNFs (only at the nodes), energy expenditure is lower in MNFs compared to NNFs.
Statement C: "The action potentials of MNF do not have a hyperpolarizing effect like that of an NNF" - CORRECT
In MNFs, K⁺ channels are concentrated at the nodes, and due to rapid conduction and localization, afterhyperpolarization is less prominent compared to NNFs where K⁺ efflux is widespread.
Statement D: "The relative refractory period is not extended in an MNF like that of an NNF" - CORRECT
Due to efficient restoration of ion gradients at nodes and faster conduction, the refractory period is shorter in MNFs, aiding rapid, successive action potentials.
Statement E: "MNFs are metabolically less efficient than NNFs" - INCORRECT
Due to limited areas of ion exchange and lower ATP use, MNFs are more metabolically efficient than NNFs.
Final answer-
Correct Statements:
C and D only (Option c)
