The Origin of Life: From Spontaneous Generation to Modern Theories, Exams of Biomedicine

Download The Origin of Life: From Spontaneous Generation to Modern Theories and more Exams Biomedicine in PDF only on Docsity! Brooks Biodiversity Unit 1 Examination 2024 with 100% answer-sheet  evolution - Correct answer the concept that all given organisms are related to each other though common ancestry  Have scientists proven that life exists? - Correct answer No  Big Bang - Correct answer Theory of how the universe formed 16-18 billion years ago  Symbiosis - Correct answer the interaction between two different organisms living in close association  "life coming together"  Spontaneous Generation - Correct answer Theory that life arose spontaneously from inanimate matter. Not a widely held belief among scientists  Biogenesis Hypothesis - Correct answer Theory that living matter created by pre- existing living matter  Haldane-Oparin Hypothesis - Correct answer "Chemical Evolution"  Life arose spontaneously from early atmospheric compounds. It was believed that the early atmosphere contained methane, ammonia, and water. When combined with energy sources, life arose. This is the original theory of how life arose, but is likely INCORRECT.  Miller-Urey Experiment - Correct answer Tested the Haldane-Oparin Hypothesis by conducting an experiment that simulated the conditions thought at the time to be present on earth, and tested for the occurrence of chemical origins of life. They took inorganic compounds and made organic compounds (mostly amino acids). DID NOT PROVE ANYTHING  Panspermia - Correct answer Hypothesis that organic molecules were brought to earth by meteorites/asteroids. Basically, life was seeded from outer space, and that life exists throughout the universe distributed by meteoroids, asteroids, comets, and planetoids.  Modern Theory of How Life Arose - Correct answer (STILL NOT PROVEN, ONLY LIKELY) life arose spontaneously from simple molecules (CO, CO2, N2,H2 (very little because it was in little abundance), and H2O), then combined into larger, complex macromolecules such as proteins, carbohydrates, lipids, and nucleic acids. (NOT from methane, ammonia, and water as Haldane-Oparin hypothesized)  Primordial Soup Hypothesis - Correct answer Hypothesized that the first organisms were heterotrophs because they consumed the abundant food molecules present in the atmosphere  The Cell - Correct answer the basic form of an entity  The Cell Theory - Correct answer every life form (from bacteria to humans) is made up of/comes from cells  Steps of the development of cells - Correct answer 1. Spontaneous formation of simple molecules (Carbohydrates, lipids, proteins, and nucleic acids)  2. Formation of lipid bilayer, polymers, and Protien-RNA systems.  3. Lipid Bilayer forms selectively permeable barrier that contains an enclosed self-replicating system. Closed system contains DNA, RNA, proteins, and enzymes. (VERY IMPORTANT!)  4. Abiotic (derived from non-living things) formation of protobiont (initial structures during the origin of life which can show at least one propery of life) using self- replicating molecules  5. Composition of anaerobic prokayotic cells, then followed by aerobic and photosynthetic prokaryotic cells  6. Single celled eukaryotic cells form and then evolve into multicellular organisms  DNA vs RNA. Which came first? - Correct answer Scientists believe RNA was first genetic material because RNA can also form ribozymes which catalyze reactions  Unresolved Problems of the Modern Theory of How Life Arose - Correct answer 1. Formation of large, complex organic molecules via dehydration or condensation bonds in an aquatic environment is a problem because of the concept of hydrolysis. Water actually breaks most things down. Since all life was originally in water, it would be hard to synthesize life.  2. Formation of the "self-replicating" system. Non-living organisms can't reproduce abiotically, which is obviously a large factor in the growth of life.  Prokaryote - Correct answer Cells without membrane bound nucleus or organelles. Pro- = Before, -Kary = Nucleus  Eukaryote - Correct answer Cells with a true membrane bound nucleus. Eu- = true, -Kary = Nucleus  Upper Part of Pangaea - Correct answer Laurasia  Lower Part of Pangaea - Correct answer Gondwana  Cenozoic Era - Correct answer WE ARE STILL IN THIS PERIOD. Began 65 million years ago.  Life's Time Clock - Correct answer Humans have been around in a relatively short period of time in the grand scheme of things. (1 minute on a 24 hour clock according to Brooks)  Taxonomy - Correct answer The science of identifying, classifying, and naming things.  Binomial Nomenclature - Correct answer bi- = two, nomi- = name.  System of naming developed by Linnaeus that gives each organism 2 names. Genus (noun), species (adjective).  Carl Linnaeus - Correct answer Goal was to name every species on the planet. He came up with Binomial Nomenclature  Classification System - Correct answer Domain (Domains) = Divine  Kingdom (Kingdoms) = King  Phylum (Phyla) = Phillip  Class (Classes) = Came  Order (Orders) = Over  Family (Families) = From  Genus (Genera) = Greece  Species = Singing  Binary Fission - Correct answer Asexual reproduction. Used in bacteria  Mutualism - Correct answer Benefit both organisms  Commensalism - Correct answer One benefits, no effect on the other  Parasitism - Correct answer One benefits, the other is harmed  coccus - Correct answer circle shaped bacteria  bacillus - Correct answer rod shaped bacteria  spirillus - Correct answer spiral shaped bacteria  Domain Eukarya - Correct answer Kingdom Archezoa  Kingdom Protista  Contain a true nucleus  Serial Endosymbiotic Hypothesis - Correct answer Hypothesis that mitochondria came first then chloroplast. Mitochondria and chloroplast were thought to have come from Eukaryotes  Kingdom Archezoa - Correct answer Create ATP anaerobically (without oxygen)  Have a true nucleus, but lack mitochondria  Giardia - Correct answer Kingdom Archezoa  Intestinal parasite of vertebrates  Caused intestinal issues which you can get from drinking tainted water  Kingdom Protista - Correct answer Typically they are eukaryotes which means that they have a defined nucleus  Typically unicellular though some are multicellular  unicellular: ciliates  multicellular: ulva  Very Diverse Group  Classification based on ecological role:  Consumer - Heterotrophic  Producer - Autotrophic  Both - Mixotrophic  Polyphyletic - Correct answer Protists are polyphyletic, meaning that they evolved similar characteristics, but not one RECENT common ancestor.  Monophyletic - Correct answer One recent common ancestor  Heterotrophic protists - Correct answer All end with -mycota which means fungus!!  Fungus-like "water molds", slime molds, and plasmodial slime molds  Phylum Chytidiomycota, Phylum Oomycota, Phylum Acrasiomycota, and Phylum Myxomycota  Phylum Chytridiomycota - Correct answer Heterotrophic Protists  Spores responsible for amphibian disease Chytridiomycosis (important) which is rapidly killing many amphibians globally  Phylum Oomycota - Correct answer Require water to survive  Can reproduce sexually via the Oogonium  Can reproduce asexually via Zoospores  Phylum Acrasiomycota - Correct answer Cellular slime mold  Unicellular protist, however can be colonial (aggregate of cells)  It is not a TRUE plasmodium because it aggregates  Cells used cAMP (acrosin) as a pheromone which cause the organisms to gather together and create a pseudoplasmodium (colony) when food is found  Reproduce via sporangium (structures that produce spores)  Fully undergoes mitosis UNLIKE plasmodial slime mold  Phylum Myxomycota - Correct answer Plasmodial Slime Mold  Forms a multinucleated cell mass known as plasmodium. This is because it does not undergo cytokinesis (cell division)  Multinucleate organisms with one big cell, which is why they are called plasmodium in contrast with pseudoplasmodium which is many cells that look like one due to aggregation  When food/water runs out, plasmodium then grow sporangium (structures that release spores for sexual reproduction)  Phylum Sarcodina - Correct answer sarco- = flesh/muscle, -dina = to spin/whirl  All have pseudopodia (cellular extensions used to move and feed)  Types:  Amoebae  Foraminiferians  Radiolarians  Amoebae - Correct answer Moves around in an amorophus way  uses lobed pseudopodia for locomotion and feeding (endocytosis)  This is why they are classified as pseudopods  Phylum Sarcodina  Foraminiferians - Correct answer Pseudopods that have Calcium Carbonate shells (ex: snails)  use thin pseudopodia (axopodia) for feeding  Phylum Sarcodina  Radiolarians - Correct answer Pseudopods that have silica shells, giving them a glass-like appearance (more transparent)  Use thin ray-like pseudopodia (axopodia/acitinopodia) for feeding and movement  Phylum Sarcodina  Phylum Ciliophora - Correct answer Ciliated, meaning that they use cilia for feeding and locomotion  most are freshwater  They have specialized organelles:  Contractile Vacuole  Extensive Cytoskeletal network  macronuclei  micronuclei  examples: Paramecium (most complex cell), Trichocysts (know both*)