Campbell Chapter 27: Mastering Biology Questions – Flashcards
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Bioremediation is _____
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the use of organisms to remove pollutants from the environment
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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
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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
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Which group was not described in Woese's tree of life analysis?
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Prokarya
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What characteristics were used to classify organisms before Woese's tree of life analysis?
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Presence of a membrane-bound nucleus
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True or false? Data showing that the Bacteria were the first lineage to diverge from the common ancestor of all living organisms suggest that the Archaea and Eukarya are more closely related to each other than they are to the Bacteria.
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True
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Which of the following statements about phylogenetic trees is true?
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A paraphyletic group consists of a common ancestor and some of its descendants.
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Which molecule did Carl Woese study to produce his tree of life?
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Ribosomal RNA
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What is lateral gene transfer?
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Physical transfer of a gene from a species in one lineage to a species in another lineage.
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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
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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?
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Euryarchaeota ... Crenarchaeota
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The prokaryotic organisms most likely to be found living in salt ponds are the _____
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halophiles
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hich statement is true about obligate anaerobes?
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They are poisoned by O2.
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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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Classify each statement or picture as applying to gram-positive bacteria, gram-negative bacteria, or both.
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Gram staining is a technique for classifying bacteria based on differences in the structure of their cell walls. Gram-negative bacteria and gram-positive bacteria both have a plasma membrane surrounded by a cell wall that contains peptidoglycan. However, the cell wall of gram-negative bacteria is composed of a thin layer of peptidoglycan and an outer membrane, whereas the cell wall of gram-positive bacteria is composed of a thick layer of peptidoglycan. Gram-negative bacteria appear red or pink because the alcohol rinse washes away the crystal violet dye. Gram-positive bacteria appear purple because the alcohol rinse does not wash away the crystal violet dye.
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Label the diagram below to show the relationship between nutritional modes of bacteria.
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Some bacteria obtain energy from light (phototrophs), whereas other bacteria obtain energy from chemicals (chemotrophs). Autotrophs (literally "self-feeders") require only an inorganic substance, such as carbon dioxide, as their carbon source; heterotrophs (literally "other-feeders") require at least one organic nutrient as their carbon source.
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Azotobacter is a genus of bacteria that live in soil and have the following characteristics: (1)They are bacilli. (2)They are gram-negative. (3)They are obligate aerobes. (4)They can fix nitrogen. (Unlike some other nitrogen-fixing bacteria, which associate with the roots of plants, Azotobacter species are free-living.)
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(1)They can convert atmospheric nitrogen to ammonia. (2)They are shaped like rods. (3)They have a relatively thin layer of peptidoglycan in their cell wall. (4)They use O2 for cellular respiration.
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Genes for the resistance to antibiotics are usually located _____.
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on plasmids
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How does the large amount of genetic variation observed in prokaryotes arise?
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The second and third answers are correct.
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What is the function of fimbriae?
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They are used to attach the cell to its substrate or to other prokaryotes.
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Which statement about the genomes of prokaryotes is correct?
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Prokaryotic genomes are composed of circular chromosomes.
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Hershey and Chase performed an elegant experiment that convinced most biologists that DNA, rather than protein, was the genetic material. This experiment subjected bacteria to the same gene transfer mechanism as occurs in
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transduction.
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Which statement about bacterial cell walls is false?
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Cell walls prevent cells from dying in hypertonic conditions.
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Which two structures play direct roles in permitting bacteria to adhere to each other, or to other surfaces? 1. capsules 2. endospores 3. fimbriae 4. plasmids 5. flagella
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1 and 3
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Prokaryotes' essential genetic information is located in the
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nucleoid.
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Which of the following is least associated with the others?
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binary fission
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Match the numbered terms to the description that follows. Choose all appropriate terms. 1. autotroph 2. heterotroph 3. phototroph 4. chemotroph a prokaryote that obtains both energy and carbon as it decomposes dead organisms
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2 and 4
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Match the numbered terms to the description that follows. Choose all appropriate terms. 1. autotroph 2. heterotroph 3. phototroph 4. chemotroph an organism that obtains energy from light
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3 only
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Match the numbered terms to the description that follows. Choose all appropriate terms. 1. autotroph 2. heterotroph 3. phototroph 4. chemotroph an organism that obtains both carbon and energy by ingesting prey
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2 and 4
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The thermoacidophile, Sulfolobus acidocaldarius, lacks peptidoglycan, but still possesses a cell wall. What is likely to be true of this species? 1. It is a bacterium. 2. It is an archaean. 3. The optimal pH of its enzymes will lie above pH 7. 4. The optimal pH of its enzymes will lie below pH 7. 5. It could inhabit certain hydrothermal springs. 6. It could inhabit alkaline hot springs.
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2, 4, and 5
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The termite gut protist, Mixotricha paradoxa, has at least two kinds of bacteria attached to its outer surface. One kind is a spirochete that propels its host through the termite gut. A second type of bacteria synthesizes ATP, some of which is used by the spirochetes. The locomotion provided by the spirochetes introduces the ATP-producing bacteria to new food sources. Which term(s) is (are) applicable to the relationship between the two kinds of bacteria? 1. mutualism 2. parasitism 3. symbiosis 4. metabolic cooperation
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1, 3, and 4
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Bacteria perform the following ecological roles. Which role typically does not involve symbiosis?
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decomposer
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Which of the following statements is not true?
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Only bacteria have histones associated with DNA.
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Genetic variation in bacterial populations cannot result from
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meiosis.
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Which of the following involves metabolic cooperation among prokaryotic cells?
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biofilms
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Plantlike photosynthesis that releases O2 occurs in
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cyanobacteria.
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Photoautotrophs use
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light as an energy source and CO2 as a carbon source
