Involves comparing the costs and benefits of consuming or producing one additional unit of a good or service.

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.

If jane has the blood type ab and marries john who has type o blood what are the possible phenotypes of their first kid?

What kind of bond is created by the attraction between atomic particles of opposite charge? ionic bond hydrogen bond covalent bond nuclear bond