Exam 28: Bacteria and Archaea

To establish a link between a specific bacterium and a skin disease,researchers have shown that bacterium was present in sick persons but not in healthy individuals.They isolated the bacterium in a pure culture and demonstrated that experimental healthy animals injected with this culture became sick.What other experiment do researchers need to perform to be absolutely sure that the bacterium is responsible for the disease?

Which of the following is correct?

What is the goal of bioremediation?

You might be interested to know how many different types of bacteria live on the shower curtain in your bathroom.What is the most efficient method for answering this question?

Bacteria and Archaea are most easily distinguished from each other by their _____.

Imagine that you are given some chemoorganotrophic bacteria to grow.What should you use as a source of energy for this type of bacteria?

Which are evolutionarily more closely related?

Figure 28.1 -Bacteria able to perform the NH₄⁺ + NO₂⁻ → N₂ + 2H₂O reaction have been discovered in laboratory bioreactors and wastewater treatment systems.Researchers predicted that these bacteria should exist in oceans.They measured the concentration of NH₄⁺,NO₂⁻,NO₃⁻,and O₂ in the Black Sea as a function of water depth (M.Kuypers et al.2003 Anaerobic ammonium oxidation by anammox bacteria in the Black Sea.Nature 422: 608-11)to determine where in the sea the bacteria might live.Analyzing data presented in Figure 28.1 above,at what depth would you expect to find the bacteria? (Note: In the figure,different scales are used to show concentrations of NH₄⁺,NO₂⁻,NO₃⁻,and O₂. )

Biologists sometimes divide living organisms into two groups: Autotrophs and heterotrophs.How do these two groups differ?

What kind of molecules serve as electron acceptors in cellular respiration?

You run an osteology lab,where students are able to study the bone structure of various species.To produce clean bones,you introduce insects and bacteria to remove all remaining flesh.Which bacteria would be the best purchase for your lab?

A bacterium was grown in two test tubes filled with media rich in glucose.One tube was sealed to produce anaerobic conditions,and the other was not.A third uninoculated,unsealed tube was used as a control.Glucose utilization by this bacterium causes acid production,which is indicated by a lightening of the media color.If the bacterium is able to produce ATP only by respiration,which result do you expect to receive?

Which of the following extremophiles might researchers most likely use as a model for the earliest organisms on Earth?

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?

You need to identify the major type of bacteria living on the shower curtain in your bathroom and find out what they use as a food source.What is the most efficient method for answering this question?

Which of the following lineages do not contain bacteria that are photosynthetic?

The purple non-sulfur bacterium Rhodospirillum grows best as a photoheterotroph.What are the most favorable sources of energy and carbon for this bacterium?

What experiment can distinguish between high-GC Gram-positive bacteria and low-GC Gram-positive bacteria?