BIOL 150 Lecture Notes - Lecture 1: Symmetry In Biology, Cephalization, Arthropod
Document Summary
Animal shared characteristics: eukaryotic, multicellular, no cell walls (lost and was never regained) exible, heterotrophic (eat other things, only multicellular heterotrophs who ingest! (causes them to be highly complex, move under own power at some point. Richness, abundance and impact: 1. 2 million species named (high richness, highest documented richness and abundance arthropods, key consumers land and water. Things as the top of the trophic structure (key consumers) have lower abundance (less energy at the top) and these animals tend to be larger. 2 different ways to make a gut that looks the same. Some have modi ed (pseudo) or lost coelem. 3 layers (endoderm, mesoderm, ectoderm) and formation of a digestive tract (gut; organs; muscles!) Changes in body plan over time: tissues / organs, gastrulation, fluid- lled coelem (arises from 3 layers, symmetry, cephalization (head): coordinates sensory structures at front. Evolving a becoming more of a thing. Bilateral (evolutionarily moving toward bilateral easier to get food this way)
