Bio Mastering 27

24 July 2022
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21 test answers

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question
What is the function of fimbriae?
answer
They are used to attach the cell to its substrate or to other prokaryotes.
question
How does the large amount of genetic variation observed in prokaryotes arise?
answer
-they have extremely short generation times and large populations -they can exchange DNA with many types of prokaryotes by way of horizontal gene transfer
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Genes for the resistance to antibiotics are usually located
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on plasmids
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Bacteria that live around deep-sea, hot-water vents obtain energy by oxidizing inorganic hydrogen sulfide belched out by the vents. They use this energy to build organic molecules from carbon obtained from the carbon dioxide in seawater. These bacteria are _____.
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chemoautotrophs
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Which statement is true about obligate anaerobes?
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They are poisoned by O2
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The prokaryotic organisms most likely to be found living in salt ponds are the
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halophiles; these archaea live in salty environments such as the Dead Sea
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How are archaeans most similar to bacteria?
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the shape of their chromosomes and plasmids; prokaryotes typically have circular chromosomes and plasmids
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An ecological relationship between organisms of different species that are in direct contact can best be described as _____.
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symbiotic; this is the definition of symbiosis
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Which statement about endotoxins is true
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endotoxins are released only when bacteria die and their cell walls break down; endotoxins are a component of the outer membrane of gram-negative bacteria
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Bioremediation is
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the use of organisms to remove pollutants from the environment
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Select the correct statement about bacteria
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certains bacteria live within rocks kilometers below the Earth's surface
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Approximately how many prokaryotic cells live in 5 mL of fertile soil?
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about 100 million prokaryotic cells
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Select the valid comparison between eukaryotes and prokaryotes.
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prokaryote cells have simpler internal structure and genomic organization than eukaryotic cells
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Which of the following processes contributes to genetic recombination in prokaryotes?
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transduction; In transduction, bacteriophages carry bacterial genes from one host cell to another, producing a recombinant bacterial genome.
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The prokaryotic cells that built stromatolites are classified as _____.
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cyanobacteria
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The prokaryotic cells that were the first to add significant quantities of oxygen to Earth's atmosphere are classified as _____.
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cyanobacteria; cyanobacteria are aerobic photosynthesizers
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Streptococcus pyogenes is classified with _____.
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gram-positive bacteria
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Organisms that can cause nongonococcal urethritis are classified with _____.
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chlamydias
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The chemoheterotroph Proteus vulgaris is a rod-shaped bacterium classified with _____.
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proteobacteria
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Spiral-shaped bacteria are likely to be placed with _____.
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spirochetes
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According to this phylogenetic tree, which of these pairs of prokaryotic subgroups share the most recent common ancestor?
answer
Euryarchaeota ... Crenarchaeota