How do homologous and analogous structures show evidence for evolution?

Homologous structures provide evidence for common ancestry, whileanalogous structures show that similar selective pressures can produce similaradaptations (beneficial features). Similarities and differences among biological molecules (e.g., in the DNA sequence of genes) can be used todetermine species' relatedness.

Evidence for evolution is provided by homologous structures. These are structures shared by related organisms that were inherited from a common ancestor. Other evidence for evolution is provided by analogous structures. These are structures that unrelated organisms share because they evolved to do the same job.

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.  

read more on -