During the propagation of a nerve impulse,the action potential results from the movement of which of the following?

Saltatory conduction occurs in

Which of the following acts is responsible for the depolarisation of the neuron?

What happens during depolarization of the nerve membrane?

Consider the statements as True/False:
$I$. The axoplasm inside the axon contains a high concentration of $K^{+}$ and negatively charged proteins.
$II$. The axoplasm inside the axon contains a low concentration of $Na^{+}$.
$III$. The fluid outside the axon contains a low concentration of $K^{+}$.
$IV$. The fluid outside the axon contains a high concentration of $Mg^{++}$ and negatively charged proteins.
The correct option is:

When a neuron is in resting state,$i.e.$,not conducting any impulse,the axonal membrane is