Exam 27: Bacteria and Archaea

The following table depicts characteristics of five prokaryotic species (A-E). Use the information in the table to answer the following question. Trait Plasmid Gram Staining Results Nutritional Mode Specialized Metabolic Pathways Other Features Species A R Variable Chemohetero- troph Aerobic methanotroph (obtains carbon and eneroy from methane) Fimbriae Species B None Variable Chemoauto- troph Anaerobic methanogen Internal membranes Species C R Negative Chemohetero- troph Anaerobic butanolic fermentation Flagellum Species D F Negative Chemohetero- \ roph Anaerobic lactic acid fermentation Pili SpeciesE None Negative Photoauto- troph Anaerobic nitrogen fixation and aerobic photosystems I and II Thylakoids How many of these species probably have a cell wall that consists partly of an outer membrane of lipopolysaccharide?

The following table depicts characteristics of five prokaryotic species (A-E). Use the information in the table to answer the question. Trait Plasmid Gram Staining Results Nutritional Mode Specialized Metabolic Pathways Other Features Species A R Variable Chemohetero- troph Aerobic methanotroph (obtains carbon and eneroy from methane) Fimbriae Species B None Variable Chemoauto- troph Anaerobic methanogen Internal membranes Species C R Negative Chemohetero- troph Anaerobic butanolic fermentation Flagellum Species D F Negative Chemohetero- \ roph Anaerobic lactic acid fermentation Pili SpeciesE None Negative Photoauto- troph Anaerobic nitrogen fixation and aerobic photosystems I and II Thylakoids Which species might include cells that are Hfr cells?

Use of synthetic fertilizers often leads to the contamination of groundwater with nitrates. Nitrate pollution is also a suspected cause of anoxic "dead zones" in the ocean. Which of the following might help reduce nitrate pollution?

Use the following information to answer the question. Nitrogenase, the enzyme that catalyzes nitrogen fixation, is inhibited whenever free oxygen (O₂)reaches a critical concentration. Consequently, nitrogen fixation cannot occur in cells wherein photosynthesis produces free O₂. Consider the colonial aquatic cyanobacterium, Anabaena, whose heterocysts are described as having "...a thickened cell wall that restricts entry of O₂ produced by neighboring cells. Intercellular connections allow heterocysts to transport fixed nitrogen to neighboring cells in exchange for carbohydrates." Think about this description of the colonial aquatic cyanobacterium, Anabaena. Which of the following questions below is important for understanding how nitrogen (N₂)enters heterocysts, and how oxygen (O₂)is kept out of heterocysts?

The following table depicts characteristics of five prokaryotic species (A-E). Use the information in the table to answer the question. Trait Plasmid Gram Staining Results Nutritional Mode Specialized Metabolic Pathways Other Features Species A R Variable Chemohetero- troph Aerobic methanotroph (obtains carbon and eneroy from methane) Fimbriae Species B None Variable Chemoauto- troph Anaerobic methanogen Internal membranes Species C R Negative Chemohetero- troph Anaerobic butanolic fermentation Flagellum Species D F Negative Chemohetero- \ roph Anaerobic lactic acid fermentation Pili SpeciesE None Negative Photoauto- troph Anaerobic nitrogen fixation and aerobic photosystems I and II Thylakoids Which species is most likely to be found in sewage treatment plants and in the guts of cattle?

Biologists sometimes divide living organisms into two groups: autotrophs and heterotrophs. These two groups differ in ________.

Which of the following is least associated with the others?

If all prokaryotes on Earth suddenly vanished, which of the following would be the most likely and most direct result?

The following question refers to the figure. In this eight-year experiment, 12 populations of E. coli, each begun from a single cell, were grown in low-glucose conditions for 20,000 generations. Each culture was introduced to fresh growth medium every 24 hours. Occasionally, samples were removed from the populations, and their fitness in low-glucose conditions was tested against that of members sampled from the ancestral (common ancestor)E. coli population. If the experimental population of E. coli lacks an F factor or F plasmid, and if bacteriophages are excluded from the bacterial cultures, then beneficial mutations might be transmitted horizontally to other E. coli cells via ________.

Use the following information and graph to answer the question. The figure below depicts changes to the amount of DNA present in a recipient cell that is engaged in conjugation with an Hfr cell. Hfr cell DNA begins entering the recipient cell at Time A. Assume that reciprocal crossing over occurs (in other words, a fragment of the recipient's chromosome is exchanged for a homologous fragment from the Hfr cell's DNA). How is the recipient cell different at Time D than it was at Time A?

The following question refers to the figure. In this eight-year experiment, 12 populations of E. coli, each begun from a single cell, were grown in low-glucose conditions for 20,000 generations. Each culture was introduced to fresh growth medium every 24 hours. Occasionally, samples were removed from the populations, and their fitness in low-glucose conditions was tested against that of members sampled from the ancestral (common ancestor)E. coli population. E. coli cells typically make most of their ATP by metabolizing glucose. Under the conditions of this experiment, E. coli generation times in the experimental lines and low-glucose conditions should ________.

The thermoacidophile Sulfolobus acidocaldarius lacks peptidoglycan, but still possesses a cell wall. Which of the following statements is likely to be an accurate description of this species?

Use the information in the following paragraph to answer the question. A hypothetical bacterium swims among human intestinal contents until it finds a suitable location on the intestinal lining. It adheres to the intestinal lining using a feature that also protects it from phagocytes, bacteriophages, and dehydration. Fecal matter from a human in whose intestine this bacterium lives can spread the bacterium, even after being mixed with water and boiled. The bacterium is not susceptible to the penicillin family of antibiotics. It contains no plasmids and relatively little peptidoglycan. This bacterium's ability to survive in a human who is taking penicillin pills may be due to the presence of ________.

The following question refers to the figure. In this eight-year experiment, 12 populations of E. coli, each begun from a single cell, were grown in low-glucose conditions for 20,000 generations. Each culture was introduced to fresh growth medium every 24 hours. Occasionally, samples were removed from the populations, and their fitness in low-glucose conditions was tested against that of members sampled from the ancestral (common ancestor)E. coli population. If the vertical axis of the figure above refers to relative fitness, then which of the following is the most valid and accurate measure of fitness?

The following table depicts characteristics of five prokaryotic species (A-E). Use the information in the table to answer the following question. Trait Plasmid Gram Staining Results Nutritional Mode Specialized Metabolic Pathways Other Features Species A R Variable Chemohetero- troph Aerobic methanotroph (obtains carbon and eneroy from methane) Fimbriae Species B None Variable Chemoauto- troph Anaerobic methanogen Internal membranes Species C R Negative Chemohetero- troph Anaerobic butanolic fermentation Flagellum Species D F Negative Chemohetero- \ roph Anaerobic lactic acid fermentation Pili SpeciesE None Negative Photoauto- troph Anaerobic nitrogen fixation and aerobic photosystems I and II Thylakoids Which species is capable of directed movement?

Genetic variation in bacterial populations cannot result from

The following table depicts characteristics of five prokaryotic species (A-E). Use the information in the table to answer the question. Trait Plasmid Gram Staining Results Nutritional Mode Specialized Metabolic Pathways Other Features Species A R Variable Chemohetero- troph Aerobic methanotroph (obtains carbon and eneroy from methane) Fimbriae Species B None Variable Chemoauto- troph Anaerobic methanogen Internal membranes Species C R Negative Chemohetero- troph Anaerobic butanolic fermentation Flagellum Species D F Negative Chemohetero- \ roph Anaerobic lactic acid fermentation Pili SpeciesE None Negative Photoauto- troph Anaerobic nitrogen fixation and aerobic photosystems I and II Thylakoids Which two species might be expected to cooperate metabolically, perhaps forming a biofilm wherein one species surrounds cells of the other species?

A hypothetical bacterium swims among human intestinal contents until it finds a suitable location on the intestinal lining. It adheres to the intestinal lining using a feature that also protects it from phagocytes, bacteriophages, and dehydration. Fecal matter from a human in whose intestine this bacterium lives can spread the bacterium, even after being mixed with water and boiled. The bacterium is not susceptible to the penicillin family of antibiotics. It contains no plasmids and relatively little peptidoglycan. This bacterium derives nutrition by digesting human intestinal contents. Thus, this bacterium is an ________.

Plantlike photosynthesis that releases O₂ occurs in

The following table depicts characteristics of five prokaryotic species (A-E). Use the information in the table to answer the following question. Trait Plasmid Gram Staining Results Nutritional Mode Specialized Metabolic Pathways Other Features Species A R Variable Chemohetero- troph Aerobic methanotroph (obtains carbon and eneroy from methane) Fimbriae Species B None Variable Chemoauto- troph Anaerobic methanogen Internal membranes Species C R Negative Chemohetero- troph Anaerobic butanolic fermentation Flagellum Species D F Negative Chemohetero- \ roph Anaerobic lactic acid fermentation Pili SpeciesE None Negative Photoauto- troph Anaerobic nitrogen fixation and aerobic photosystems I and II Thylakoids Which two species should have much more phospholipid, in the form of bilayers, in their cytoplasms than most other bacteria?