Why do cells like bacteria need a certain environment to live?

WHEN LIVING CONDITION BECOME UNFAVORABLE, SOME BACTERIA FORM SPECIAL, DEHYDRATED CELLS CALLED ENDOSPORES. ... Although the Original Cell may be Destroyed (Die) by harsh conditions, its Endospore will survive. They help bacteria resist High Temperature, Harsh Chemicals, Radiation, Drying, and other environmental extremes.

Explanation:

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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i believe the correct answer is d