Which term describes a deficiency of spermatozoa in the semen?

In the context of the neural impulse, which of the following is true about the depolarization of neuron membranes?

Coquina, a type of limestone, forms from shell fragments that settle on the ocean floor. what type of rock is coquina?

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.