How Individuals in a species have genetic variation that can be passed on to their offspring

Genetic variation within a species can result from a few different sources. Mutations, the changes in the sequences of genes in DNA, are one source of genetic variation. ... As a result, the tree-colored moths are more likely to survive, reproduce, and pass on their genes

Explanation:

the answer that best describes the relative refractory period in the neuron is the resting membrane potential is restored, but concentrations of sodium and potassium are not restored to their original state.

the refractory period is the time during which another stimulus given to the neuron will not lead to a second potential. thus, because na+ channels are inactivated during this time, additional depolarizing stimuli do not lead to new action potentials.  

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