The site of red blood cell production in an adult is the

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 primary organisms involved in the process bacteria and fungi.

The smallest biological units that can evolve are