DNA is composed of peating structural units called
is the five-carbon sugar found in
DNA.
DONE

Explanation:

if u mean repeating structural units of the DNA they are nucelotides or nucleotide bases.

and Yes, there is a five-carbon sugar in the DNA. It's called deoxyribose.

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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