Biology 3602A/B Lecture Notes - Lecture 22: Filter Feeder, Radula, Defecation
5 Aug 2016
School
Department
Course
Professor
Document Summary
22 (almost all) animals are heterotrophic: have to get energy from consuming something else. Autotrophic is an organism that can make its own energy. Animals don"t eat regularly digestible, assimilatable amino acids or sugars, they eat other organisms. Other orgs have complex fats, complex carbs, and complex proteins, but have to digest it to make it into simpler compounds to take in the nutrition. Simplest one to visualize is that of an earthworm. Stomach on one end, anus on the other end, and a bunch of stuff in between. This seems very primitive, but there are animals with even more primitive guts. Sea anemone, and flatworms (platyhelminths) have a gut with only 1 opening. Everything goes in through one opening, digestion occurs within the gastrovascular cavity, and waste is ejected out the same opening. This is a very simple body plan, and it"s the body plan from which all other animals evolved from.
