When the electrical impulse arrives from the brain, channel opens. What mineral enters the neuron?

How do cells grow and reproduce to maintain homeostasis?

Why do leaves change color in the fall? green pigments break down and no longer mask the color of chlorophyll. chlorophyll breaks down and no longer masks the colors of other pigments. red- and yellow-colored pigments grow and mask green-colored chlorophyll. green-colored chlorophyll breaks down and turns red and yellow.

Which type of respiration takes place when there is no oxygen present