Given below is a diagram of a resting nerve fibre in a polarised state. Select the option which illustrates the correct distribution of $Na^{+}$ and $K^{+}$ ions along the membrane.

During the transmission of a nerve impulse,the potential inside the membrane undergoes which of the following changes in charge?

Give scientific reasons:
$(1)$ There is no physical connection between sequential neurons,yet nerve impulses are conducted through them.
$(2)$ The neuroplasm of a neuron contains a high $K^+$ concentration during the maintenance of the resting potential.

Which of the following processes are responsible for the transport of $Na^+$ from outside to the inner side of the axon membrane during the generation of a nerve impulse?

The conduction of nerve impulse is a

An action potential in a nerve fiber is generated when the $+ve$ and $-ve$ charges on the outside and inside of the axon membrane are reversed because ...........