1. Discuss the differences in teeth and digestive tracts among mammalian omnivores, herbivores, and carnivores.
2. Considering cnideria and planeria compared to earthworms and insects, discuss the increased need for separation and sophistication of the digestive, respiratory, and circulatory systems.
3. Explain the earthworm's stomach (which is divided
into crop and gizzard) compared to both the cow's stomach (with
four separate areas to hold and digest food) and the simpler stomach
of a human or a cat. Discuss how these specializations are related
to diet.