While studying the embryos of deer and hens, Bryan found marked similarities in them. Even though deer and hens are very different as adults, their embryos are very similar. Which of the following correctly explains this similarity? A. Deer and hens share an common, early ancestor. B. Deer and hens share a common, recent gene pool. C. Deer and hens share a common habitat.

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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what's the question ?

i believe it would be c: tons.