The mitochondrion is the place in the cell where

a. the dna is copied
b. cellular respiration takes place
c. fermentation takes place
d. energy is converted to waste

B is the answer, because it is considered the "power house" of the cell, and energy stored in the mitochondrion is synthesized.

Hope I helped!

~Mschmindy

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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