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54 Cards in this Set
- Front
- Back
T/F: There are archaean prokaryotes that can live in salinity that would kill most all other organisms because they pump out K+ ions until their insides match the concentration of the environment.
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True
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Most bacteria are _ - _ μm.
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.5 - 5
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What are the names for spherical and rod-shaped bacteria, respectively?
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Cocci and bacilli
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What are the suffixes describing the number of bacteria within a sample?
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Di - 2, strepto - chains, staphylo - grapelike clusters
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Most bacterial walls contain _, a network of modified-sugar polymers cross-linked by short polypeptides.
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Peptidoglycan (archaeal walls lack this)
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What type of bacteria have simpler walls with a relatively large amount of peptidoglycan?
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Gram-positive
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What type of bacteria have less peptidoglycan and are structurally more complex?
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Gram-negative (contain lipopolysaccharides, carbs bonded to lipids)
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Why do antibiotics work (mostly on gram-positive bacteria)?
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Because they inhibit peptidoglycan cross-linking and cause the cell wall to no longer be functional
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A sticky layer covering the cell wall of many prokaryotes is called the...
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Capsule
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What are the two names for hairlike protein appendages called?
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Fimbriae and attachment pili
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What are appendages called that pull two cells together prior to DNA transfer from one cell to the other?
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Sex pili
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T/F: Prokaryotic flagella are much smaller and different in composition than eukaryotic flagella.
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True
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What is taxis, chemotaxis, and what are the types of this?
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Taxis is the movement of flagella in response to a stimulus, chemotaxis being in response to a chemical; positive is movement toward nutrients, oxygen or other bacteria; negative is away from a toxic substance.
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A region of cytoplasm in a prokaryote that appears lighter than the surrounding cytoplasm in electron micrographs where the DNA is found is called the...
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Nucleoid
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The much smaller rings of separately-replicating DNA in a prokaryote is called a...
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Plasmid
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T/F: Prokaryotes are small, they reproduce by binary fission, and they have short generation times.
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True
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What resistant cells can some bacteria form when an essential nutrient is lacking?
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Endospores (where a copied chromosome is surrounded by a hard wall, removed of all water, and then separated to survive on its own)
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T/F: Prokaryotes are so diverse that just the rRNA gene from two strains of e.coli differ more than the same genes from a human and a platypus.
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True
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T/F: Mutations in bacteria are so common that, after all the math, about 9 million will have encountered mutations in just ONE human host because of the high rate of reproduction.
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True
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The combining of DNA from two sources is called...
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Genetic recombination
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What three processes can bring about genetic recombination from two different individuals in prokaryotes?
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Transformation, transduction, and conjugation
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What is transformation?
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It is when an alive prokaryote is subject to DNA of another organism and incorporates this DNA into its own genome, creating a recombinant chromosome.
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What is transduction?
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It is when a virus (bacteriophage) takes the DNA of of bacteria and then injects it into the genome of another, (it usually cannot reproduce itself bc it then lacks its own DNA), and thus recombinant chromosomes are made.
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Does the original infecting phage or a new one created by the bacterial host cell infect the recipient bacteria?
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A new one containing DNA from the host cell
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What is conjugation?
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A process in which genetic material is transferred between two bacterial cells, using sex pili and a "mating bridge"
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What must a bacteria have in its genome in order to be able to form sex pili and to perform conjugation? Where may it exist?
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The F (fertility) factor; may exist in the plasmid or in the bacterial chromosome
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What is the difference between an F+ and an F- bacterium?
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F+ have the F factor in the plasmid and are the donors during conjugation; F- do NOT have the F factor and are the recipients during conjugation
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T/F: Chromosomal genes (rather than plasmid genes) can be transferred during conjugation when the donor cell's F factor is integrated into the chromosome.
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True
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A cell with the F factor built into its chromosome is called an...
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Hfr cell (high frequence of recombination cell)
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T/F: In conjugation between F+ and F- bacteria, both end up with half of the original F plasmid, and half of a new, replicated plasmid.
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True
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What ultimately happens in conjugation and transfer of part of an HFR bacterial chromosome?
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The recipient bacterial chromosome is recombinant but does not contain a full F factor; it is still F-.
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Resistance genes in bacterial plasmids are called...
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R plasmids
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T/F: Even R plasmids can sometimes code for sex pili and thus increase the amount of bacteria with resistance genes.
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True
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So what are the 3 main reasons for the rapid adaptations of prokaryotes?
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Rapid reproduction, mutation, and genetic recombination
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Organisms that need only an inorganic compound such as CO2 for a carbon source are called...
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Autotrophs (light users are called phototrophs)
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What type of organisms require at least one other organic nutrient, such as glucose, to make other organic compounds?
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Heterotrophs
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How does a chemoautotroph differ from a photoautotroph?
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It needs inorganic substances (NH3, H2S, Fe2+) in addition to CO2 but in replacement of light.
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What type of animals harness energy from light but most obtain carbon in organic form?
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Photoheterotrophs
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What are humans?
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Chemoheterotrophs
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When prokaryotes convert atmospheric Nitrogen (N2) to ammonia (NH3) it is called...
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Nitrogen fixation
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Within an bacterial filament colony, some bacteria undergo photosynthesis while others perform nitrogen fixation. What are these nitrogen-fixing bacteria called?
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Heterocytes
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Metabolic cooperation between different prokaryotic species often occurs in surface-coating colonies known as...
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Biofilms
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Why are archaean "methanogens" named this?
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Because they have methane as a huge waste product (obligate anaerobes)
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In proteobacteria, what subgroup is closely associated with eukaryotic hosts?
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Alpha
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In proteobacteria, what subgroup are generally soil bacteria?
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Beta
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In proteobacteria, what subgroup includes bacteria that oxidize sulfur?
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Gamma
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In proteobacteria, what subgroup secretes slime?
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Delta
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In proteobacteria, what subgroup is generally pathogenic?
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Epsilon
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Spirochetes move by...
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Rotating through their environments
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What are the bacteria with plant-like, oxygen-generating photosynthesis?
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Cyanobacteria
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What is the smaller organism (not the host) called in a symbiotic relationship?
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The symbiont
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Proteins secreted by certain bacteria and other organisms are called...
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Exotoxins
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Lipopolysaccharids components of the outer membrane of gram-negative bacteria are called...
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Endotoxins (released only after death)
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The use of organisms to remove pollutants from soil, air, or water is called...
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Bioremediation
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