Lab 3 Questions- Describe the differences/similarities between each of the 3 domains of lifeo Domain Archea Prokaryotic Cell walls lack peptidoglycan Plasma membrane lipids are ether links Has several (8-12 subunits each) RNA polymerase Initiator tRNA is Methionineo Domain Bacteria Prokaryotic Cell walls contain peptidoglycan Plasma membrane lipids are ester links between polar heads and fatty acidtails Has one (4 subunits) RNA polymerase Initiator tRNA is Formylmethionineo Domain Eukarya Eukaryotic Cell walls lack peptidoglycan- Fungus cell walls contain chitin- Cellulose cell walls contain cellulose Plasma membrane lipids are ester links Has three (12-14 subunits each) RNA polymerase Initiator tRNA is Methionine- Definitions:o Aerobic Bacteria Require oxygeno Anaerobic Bacteria Require low or zero oxygen environmento Facultative Aerobic Bacteria Like oxygen, but may get by without ito Theory of Endosymbiosis Mitochondria resulted from the engulfment of aerobic bacteria Chloroplasts resulted from the engulfment of cyanobacteriao Protists Membrane bound organelles and DNA contained in a nucleus Most diverse group of organisms in terms of both structure and function Single celled eukaryotes- Explain several reasons for why bacteria are important to the global ecosystemo Carbon Cycle Decomposition & Respirationo Oxygen Cycle Photosynthesis & Respirationo Nitrogen Cycle Nitrogen Fixation- Describe two ways in which bacteria obtain energyo Heterotrophs Cannot make own foodo Autotrophs Can make own food, from light or chemicals- How are cyanobacteria different from other bacteria?o Important players in each of the main nutrient cycles and are photosynthetico Cyanobacteria are important Nitrogen-fixers and have specialized cells calledheterocysts used in nitrogen-fixationo May survive harsh environments through the production of spore-like cells calledakineteso- Understand/describe the characteristics of each of the groups discussed in these noteso Group Diplomonadia Mainly parasitic 2 nuclei (Diplo) Multiple flagella No mitochondrial DNA or “normal” Krebs cycle Ex. Giardia (Intestinal Parasite)o Group Parabasalia Symbionts and parasites 1 nucleus No plastids present No functional mitochondria Golgi complex associated with multiple flagella via parabasal fibers Ex. Trichomonas vaginalis (STD)o Group Euglenozoa Many lifestyles 1-2 flagella containing a crystalline rod Two subgroups of euglenozoans - Euglenidso 2 flagella originating from within an infolded structureo Most are photosynthetico Ex. Euglena o- Kinetoplastidso Possess a single, large mitochondria called a kinetoplasto Undulating membrane used for locomotiono Ex. Trypanosoma (Causes African Sleeping Sickness)oo Group Alveolata Have membranous sacs underneath the cell membrane called alveoli- Subgroupso Dinoflagellates 2 flagella in grooves Internal armor made of cellulose plates Important to ecological primary production orsymbiotic such as with coral Some species are toxic- Red tide- Paralyiic Shellfish Poisoningo Apicomplexans Animal parasites Infectious stage is a cell called a sporozoite Possess a plastid celled an apicoplast Ex. Plasmodium viviax (Parasite that causesmalaria)o Ciliates Cillia used for locomotion and feeding Many have two nuclei- Macronucleuso Metabolic function- Micronucleuso Genetic DNA & Reproduction Ex. Parameciumo Group Stramenopila 2 flagella - One “Hairy” and the other “smooth”- May only be seen in reproductive cells Two subgroups- Oomycetes (Water Molds)o Parasitic or saprophytic (lives on dead matter or organicmatter)o Cell wall composed of celluloseo Structure celled an oogonia produces sessile egg nucleio Ex. Achyla Saprolegnia (Potato Blight)o- Bacilariophytes (Diatoms)o Cell wall composed of hydrated silica plateso Carbohydrates stored as laminarin (oils may also be stored)o Uses Filtraton Nanotechnologyoo Group Forams Filamentous pseudopodia extended outward through pores in a test (shell)for food engulfment Test composed of calcium carbonateo Group Radiolaria Filamentous pseudopodia radiate from a central point Test made of silica instead of calcium carbonateo Group Amoebozoa No test present Lobe-shaped pseudopodia (mobility and food capture) Ex.
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