What type of DNA was discovered by investigating why some fruit flies have wing spots and others don’t?

Paintbrush gene switch on and off

Explanation:

The study on the Fruit fly by Sean Carroll showed that the expression of a trait is controlled by the switch which turns on and off the genes involved in the spots on the wings.

The gene which is responsible for the wing spots is known as paintbrush genes and when they are activated by the switch express the traits and when switched off do not express the trait.

Thus, in the case of wing spots in the fruit fly, the flies with spots show an expression of the paintbrush genes and without wings do not show the expression of genes.

Thus, the Paintbrush gene switches on and off is correct.

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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