If one parent has blood type AB and the other has blood type A, which blood type could a child of theirs have

Ab or A or B

Explaination:

I think it that, since that's the blood types that have the highest chance from Blood type AB and A

it has one origin of replication, but it proceeds in two directions - d)

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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