Which are characteristics of natural selection?

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.

The transport tubes for food coming down the plants are called?

The type of fossil where the name literally means "turning to stone".