What is the significance of the second cell division in sexual reproduction

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.

(amoeba sisters video recap: pedigrees and need

The two main stages of cell division are called