What happens when a neuron at rest is stimulated to a level that reaches threshold?

The correct answer is: it fires an action potential.

Explanation:

Neurons at rest have a resting potential that describes the differences in voltage across the membrane. When a depolarization current is applied onto the resting neuron, it can cause an action potential if the threshold is reached. This action potential describes a sudden electrical activity that is responding to the stimulus -the current- that arrived at said neuron. When the action potential occurs, the voltage-gated sodium channels in the membrane are opened and thus allow a big influx of this ion into the cell, increasing the membrane potential even more quickly.

lunar landing mission. apollo 11 was the first manned mission to land on the moon. the first steps by humans on another planetary body were taken by neil armstrong and buzz aldrin on july 20, 1969. the astronauts also returned to earth the first samples from another planetary body.

explanation:

c. live where it’s cold and icy