Nitrogen gas

Question

Nitrogen gas

Quizplus · Accepted Answer

Nitrogen gas is relatively stable and inert, and cannot be readily assimilated by most living organisms. However, it can be reduced to ammonia through the energy-intensive process of nitrogen fixation, either through lightning strikes, industrial processes, or by certain bacteria and cyanobacteria in the environment.

Answer: C 
 While nitrogen gas is not directly available to most plants or organisms, certain symbiotic bacteria living in legume roots or free-living in the soil can fix nitrogen into a more useable form, such as ammonia or nitrate, which can then be taken up by the plant. Thus, nitrogen gas indirectly serves as a source of nitrogen for many plants.

Answer: D 
 Nitrogen gas is not formed by nitrification, but rather nitrification is the process by which ammonia (or ammonium) is oxidized by certain bacteria in the soil into nitrite and then finally to nitrate, a form that can be taken up by plants.

Answer: E
 Nitrogen gas is not a significant, direct contributor to the nitrogen in humans. Rather, humans and other animals obtain nitrogen through dietary sources, such as plant or animal proteins.

Nitrogen Gas