Gene regulation means A. The genes in some cells are different than the genes in other cells.
B. only some specialized cells can become other specialized cells.
C. genes can be turned on and off.
D. all the genes must be turned on.​

C genes can be turned on and off

Explanation:

Gene regulation is the ability to induce or repress the expression of a gene

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 think that c)gold was found there

but i am not sure