Can someone PLEASE help I will mark brainlist!

C. Mutations are all permanent. Mutations can occur in many types of cells, and contribute to genetic diversity. Not all mutations are caused by harmful chemicals, as there are many natural mutations in nature. However, mutations are not always passed on from parents to offspring.

a. decomposes use carbon from dead organisms as fuel for cellular respiration, returning carbon dioxide back into the atmosphere.

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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