Exam 27: Prokaryotes

A bacterium that lives in the human intestine derives its nutrition by digesting the contents of the intestine. Which mode of nutrition best describes this bacterium?

Which of the following statements correctly describes both phototrophs and chemotrophs?

Anabaena is a cyanobacterium with two types of cells. One type of cell can carry out photosynthesis and the other type can carry out nitrogen fixation. However, the oxygen produced by photosynthesis inhibits the enzymes for nitrogen fixation. Which structural characteristic allows the nitrogen-fixing cells to continue to function?

The following table depicts characteristics of five prokaryotic species (1-5). Use the information in the table to answer the question. Which two species might be expected to cooperate metabolically, perhaps forming a biofilm wherein one species surrounds cells of the other species?

What is one of the primary benefits of bioremediation?

The following table depicts characteristics of five prokaryotic species (1-5). Use the information in the table to answer the question. Species 4 is pathogenic if it gains access to the human intestine. Which other species, if it coinhabited a human intestine along with species 4, is most likely to become a recombinant species that is both pathogenic and resistant to some antibiotics?

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 processes is most likely to help reduce nitrate pollution?

Which of the following extremophiles is the best model for the earliest organisms on Earth?

Use the following information and graph to answer the question. The figure 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 a fragment of the recipient cell'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?

Which of the following involves metabolic cooperation among prokaryotic cells?

Assuming that each of these prokaryotes possesses a cell wall, which ones are expected to be most strongly resistant to significant water loss in hypertonic environments?

The following question refers to the figure. In this eight-year experiment, a population of E. coli, begun from a single cell, was 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 population, and its ability to grow 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, how would beneficial mutations be transmitted horizontally to other E. coli cells?

A bacterium has the following characteristics: ∙ It adheres to the human intestinal lining using a feature that protects it from phagocytes, bacteriophages, and dehydration ∙ It can survive being boiled ∙ It contains no plasmids and relatively little peptidoglycan Which of the following statements best describe the cell wall of this bacterium?

Bacteria perform a number of ecological roles. Which role typically involves symbiosis?

A bacterium has the following characteristics: ∙ It adheres to the human intestinal lining using a feature that protects it from phagocytes, bacteriophages, and dehydration. ∙ It can survive being boiled. ∙ It contains no plasmids and relatively little peptidoglycan. ∙ The bacterium is not susceptible to the penicillin family of antibiotics. ∙ The cell also lacks F factors and F plasmids. Which of the following statements about the bacteria is most probably accurate?

The following table depicts characteristics of five prokaryotic species (1-5). Use the information in the table to answer the question. Which species is most likely to be found in sewage treatment plants and in the guts of cattle?

The following table depicts characteristics of five prokaryotic species (1-5). Use the information in the table to answer the following question. Which of the above species have a cell wall that consists partly of an outer membrane of lipopolysaccharide?

While examining a rock surface, you have discovered an interesting new organism. Which of the following criteria will allow you to classify the organism as belonging to Bacteria but not Archaea or Eukarya?

Recently, a microbe that is able to digest cellulose was discovered in a hot spring with an average temperature of 95°C. This microbe most likely belongs to which of the following groups?

What line of evidence would support a hypothesis that a newly discovered bacterium is a cyanobacterium?