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. )
A)in the top 5 meters
B)in the top 50 meters
C)at a depth of 75 meters
D)at a depth of 92 meters
E)below 100 meters

Question

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. )
A)in the top 5 meters 
B)in the top 50 meters 
C)at a depth of 75 meters 
D)at a depth of 92 meters 
E)below 100 meters

Quizplus · Accepted Answer

The bacteria perform anaerobic ammonium oxidation, which requires low oxygen levels. At 92 meters, the oxygen concentration is likely low enough to support these bacteria.

Figure 28.1 -Bacteria Able to Perform the NH₄⁺ + NO₂⁻ → N₂