6. Which of the following are the control variables? A. Both number of fish and temperature B. Both temperature and light
I
C. Both light and behavior of fish
D. Both number of fish and behavior of fish

Option (A)

Explanation:

As temprature can be regulated as well as the number of fish can be changed

it is prolly d and c and f

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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