Animals' internal body structures can either be coelomate, acoelomate, or pseudocoelomate. this means they may or may not have a heart a circulatory system lungs a body cavity

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.

How is synaptic signaling different from paracrine signaling?

Can result as a complication of diabetes due to damage to the arterial walls and excess fat in the blood.