BIO SCI 94 Lecture Notes - Lecture 4: Synapomorphy, Sphagnum, Fertilisation

• School: UC-Irvine
• Department: Biological Sciences
• Course: BIO SCI 94
• Professor: Nancy Burley

Document Summary

Introduction to protists: protists, the first eukaryotes, paraphyletic group of eukaryotic organisms, mostly single-celled, but are large, earliest fossils are 2. 1 by, 60,000 identified species, characteristics. Evolution of meiosis, multicellularity: prokaryotes vs. eukaryotes, prokaryotes. Nucleolus is the site of ribosome production: evolution of early eukaryotes, ancestral protest. Next step (hypothesis): evolution of the mitochondrion (aerobic respiration: could evolve from scratch (new, could evolve by endosymbiosis of aerobic bacteria and anaerobic protest, endosymbiosis. Evidence that shows mitocondrion"s structure follows this: size, replication pattern, ribosomes, has 2 membranes, genome is similar in form and gene sequences to bacteria. Chloroplasts also evolved this way: protistan innovations, sexual reproduction. Food scarcity/high population density linked to switching from sexual to asexual reproduction. Cell to cell communication, cell specialization, cell adhesion: ecological roles. Plankton: tiny organisms found in large numbers. Diatoms: up to 45% of primary production of ocean, primary production. Organic compounds produced through photosynthesis: pathogens/parasites. Plasmodium: causes malaria, transmitted by mosquitos.