Question

which of the following statements about the nitrogen cycle is false? group of answer choices denitrification represents a gain of biologically available nitrogen in an ecosystem. atmospheric nitrogen exists primarily in the unreactive dinitrogen gas form. human activities have greatly altered the global nitrogen cycle. the nitrogen cycle is tightly coupled to the carbon cycle. bacteria with the enzyme nitrogenase perform nitrogen fixation and converts

Answer 1

Answer: A. denitrification represents a gain of biologically available nitrogen in an ecosystem

Explanation: Denitrification the process in which Nitrate (NO3) is reduced and the product of that is Nitrogen(N2), there is not a net gain of biologically available nitrogen, as the gas is released into the atmosphere and is unusable in that ecosystem.

Answer 2

The false statement is that nitrification involves the conversion of nitrites into ammonium; in reality, nitrification converts ammonium into nitrites and then nitrites into nitrates.

Step-by-step explanation:

The nitrogen cycle is essential for the transformation and movement of nitrogen through the environment, particularly for the synthesis of organic compounds used by living organisms. One process in the nitrogen cycle is denitrification, where bacteria convert nitrates (NO3-) back into nitrogen gas (N2), releasing it back into the atmosphere. Another process is nitrification, a two-step reaction that first converts ammonium (NH4+) into nitrites (NO2-) and then nitrites into nitrates (NO3-). This is distinct from nitrogen fixation, where bacteria convert atmospheric nitrogen (N2) into a form that living organisms can use, such as ammonia (NH3) or ammonium (NH4+).

In the context of the provided statements, the false statement regarding the nitrogen cycle is the one that mistakenly describes nitrification as the conversion of nitrites (NO2-) into ammonium ion (NH4+). This is incorrect because nitrification actually converts ammonium into nitrites first, and then nitrites into nitrates, not the other way around.