When DNA is duplicated during mitosis: two molecules are formed, each with an original "upright"
the original molecule thickens and separates into two
two completely new DNA molecules are formed
one completely new DNA molecule is formed

i'm sorry, but can you list the answers? i cannot with something i don't know the answers to

,

chris

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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