Myles Dye 03 14 2014 BIO 104 Dr Bej Classification Exam 2 Study Guide the classification of living animals Taxonomy Classification another to differentiate between them Taxonomy allows the establishment of relationships between one group of organisms and o Classification of organisms that have not yet been studied in detail o Identification of organisms that have already been classified o Universal language of communication o Common reference for identification Most fundamental taxonomic division Prokaryotes and Eukaryotes o Prokaryotes evolved first o Eukaryotes evolved from prokaryotes Five Kingdom Classification Whittakey 1969 o Prokaryotes Monera Protista Eukaryotes mostly unicellular Fungi absorption Plantae photosynthesis Animalia Ingestion 1 Prokaryotes are the ancestors of Eukaryotes 2 The 4 Eukaryotic Groups are distinguished according to nutritional requirements patterns of development tissue differentiation and possession of 9 2 flagella 9 pairs plus 2 in the middle 3 Protista have flagella at some stage of life cycle Multicellular protists lack tissue differentiation includes fungus like water molds slime molds protazoans and primitive eukaryotic algae 4 Fungi unicellular yeasts multicellular molds mushrooms a Absorb dissolved organic matter through plasma membrane saprophytic b Have thin tubelike structures called hyphae which are divided in to multi nucleated units by crosswalls that have holes so the cytoplasm can flow between the cell like units 5 Plantae some algae mosses ferns conifers and flowering plants a Multicellular b Photosynthesis 6 Animalia a Sponges worms insects vertabrates b Ingest organic matter through a mouth Three Kingdom Sequence Woese Based on nucleotide sequence Cell Archebacteria Ancient Bacteria o Methanogers o Halophiles Anerobes that produce methane Found in high salt locations o Thermoacidophiles Found in hot acidic environments Eukaryotes Kingdoms o Protists o Fungi o Plants o Animals Eubacteria Super Kingdoms 1 Archaebacteria and Eubacteria though similar in appearances have their own separate branches on the evolutionary tree 2 Archaebacteria differ from Eubacteria a No peptidoglycan in cell walls b Live in extreme environments c Unusual metabolism 3 It was originally thought that archaebacteria are the most primitive forms of life and eubacteria were more closely related to Eukaryotes a Studies on DNA sequencefor the RNA polymerase gene have shown more similarities between archaebacteria and eukaryotes than archaebacteria and eubacteria i Eubacteria evolved first then archaebacteria and then eukaryotes b Studies on DNA sequences of gene for rRNA have revealed that eukaryotes evolved from archaebacteria i Thermoplasma original archaebacterium has chromosomes with proteins similar to eukaryotic histones The 3 Kingdom Classification answers the question of the origin of Eukaryotes The 5 Kingdom Classification is the more useful taxonomic tool Scientific Nomenclature 18th Century Scientists Carolus Linnaeus o Every Organism has 2 names Binomial Nomenclature Genus and Species underlined or italicized Genus name Capitalized Noun Species name lower case adjective Homo Man sapiens wise Taxonomic Hierarchy Bacterial Classification o Kingdom Phylum Class Order Family Genus and Species o Kingdom Prokaryote Monera o 4 divisions 1 G cell wall Non photosynthetic bacteria Anaerobic photosynthetic bacteria Cyanobacteria 2 G cell wall Rods and cocci Actino mycetes and related organisms 3 Wall less Prokaryote Mycoplasma 4 Unusual Walls The Origin of Life The Earth originated as a hot mass of molten rock 4 5 Billion yrs ago The crust cooled and solidified 3 8 B yrs ago Water vapor condensed and cooled into liquid water which accumulated on the surface in chemically rich oceans Life arose spontaneously from those early waters Oldest prokaryote fossils came from 3 5 B yrs ago Eukaryotes evolved 1 5 B yrs ago Oldest Evidence of Life marshes Stromatolites banded domes of sediment similar to layered mats made by bacteria in salt Fossils of Prokaryotes have been found in stromatolites 3 5 B yrs old in W Australia and S Africa THESE ARE THE OLDEST EVIDENCES OF LIFE The W Australia fossils appear to be of photosynthetic organisms Therefore life must have evolved long before them Chemical Evolution in the 1920 s Oparin and Haldane independently postulated the conditions of early Earth favored the chemical synthesis of organic compounds from inorganic precursors in the atmosphere and in the seas the early atmosphere did not have oxygen and there was sources of energy such as lightning U V radiation volcanic activity and meteorite bombardment This cannot happen today because of atmospheric oxygen In 1953 Miller and Urey tested the Oparin Haldane hypothesis They created in an apparatus the conditions of early Earth The atmosphere had H2O H2 CH4 and NH3 The apparatus produced a variety of amino acids and other organic compounds o The experiment has been repeated many times and reproduced all 20 amino acids lipids purines pyrimidines and ATP It proves that chemical evolution can produce the chemical building blocks of life Synthesis of Organic Polymers Proteins are polymers of amino acids In cells enzymes catalyze there synthesis of proteins In the lab when dilute solutions of organic monomers are dripped on hot sand clay or rock polymerization occurs Such polypeptides produced by abiotic methods called proteinoids have been produced by Sidney Fox Clay may have been important as a lattice that brought monomers close together Amino acids and other monomers bind to the charged sites on clay particles and thus get concentrated Iron Pyrites could have served as a substratum for organic synthesis Protobionts Are aggregates of abiotically produced molecules that maintain an internal environment and have some of the properties associated with life such as metabolism and excitability They are not capable of precise reproduction Living cells were preceded by protobionts Protobionts could have formed spontaneously from abiotically produced organic components When mixed in cool water proteinoids self assemble into tiny droplets called microspheres Lipids spontaneously form liposomes o Simple lipid o Complex lipid triglyceride 3 fatty acids posses a hydrophilic head and hydrophobic tail RNA DNA The first genetic material Short polymers of ribonucleotides have been produced in the test tube By putting together an RNA strand and ribonucleotides in a test tubes a sequence of 5 10