BIOL 110 Lecture Notes - Lecture 14: Endomembrane System, Phototaxis, Simple Eye In Invertebrates
Document Summary
Biol 110 - lecture 14 - introduction to protists. Fundamentally single-celled eukaryotes with membrane-bound nuclei and organelles. Appear to be relatively simple, but are actually rather sophisticated. Have all essential metabolic functions such as respiration, photosynthesis, digestion, and excretion. Ex: euglena possess the following within a single cell. Eyespot and light detector to discern the direction of the most intense light (phototaxis) Metabolically diverse group that range from photosynthetic autotrophic species to heterotrophic species. Ecologically diverse group that range from marine to freshwater to terrestrial. Have diverse relationships that range from being various symbioses to just free-living. Because of their diversity, protistan taxonomy is still uncertain. There are arguments for a new classification system. Scientists generally agree that protists as a group are paraphyletic. Paraphyletic means to have descended from a common ancestor or ancestral group but not including all descendent groups.
