Some animals, but not humans, have an organ called a gizzard located near the top of their digestive tract. This organ is small and can contain small rocks. It also has thick, muscular walls. Based on this physical description, which of the following is most likely to be the function of this organ?
The gizzard is used for the preparation of digestion. The food is ground by the action of the muscular walls and also the gravel inside the gizzard.