What is the purpose of apoptosis?

It programs cells to self-destruct so that they can be recycled.

Apoptosis is programmed cell death, it is used to destroy unwanted cells and to destroy damaged cells that cannot repair themselves. It also helps prevent cancer by causing cancerous cells to destroy themselves.

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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