Bacteria Able to Perform the NH4+ + NO2− → N2

question 2

Multiple Choice

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. By analyzing data presented in the accompanying figure, 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

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Definitions:

Naturalistic Observation

A research method in which a researcher views and records an individual’s behavior in natural, real-world settings.

Clinical Interview

A method of assessment where a clinician interacts with a client to gather information about their psychological state, history, and functioning.

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Evolutionary Development

An approach in biology that studies the connections between evolutionary processes and the development of individual organisms (also known as evo-devo).