Species are characterized by the fact that they are reproductively isolated from other groups, which means that the organisms in one species are incapable of reproducing with organisms in another species.
Brief sequential change in the membrane potential of excitable cells after stimulus is called action potential whereas membrane potential represent charge difference across the membrane
In a typical neuron cell, membrane potential of cytoplasm is negative at rest and hence called resting membrane potential
Resting membrane potential of excitable cells is established by Na+ K+ pump and maintained by K+ leaky channels at rest
Phases of action potential includes: depolarization, repolarization, hyperpolarization and resting membrane potential
Depolarization starts when a threshold stimulus is applied on a neuron when via Na+ mechanically operated channels that trigger action potential
Depolarization of membrane potential is due to influx of Na+ via voltage gated Na+ channels
Repolarization starts with the efflux of K+ by the opening of voltage gated K+ channels, voltage gated K+ channels starts to open when voltage gated Na+ channels becomes inactive
Hyperpolarization occurs due to excessive efflux of K+ by voltage gated K+ channels
Additional efflux of K+ occurs due to slow inactivation of voltage gated K+ channel
