All living things need nitrogen.How does nitrogen enter the living portion of an ecosystem?

Question

Quizplus · Accepted Answer

Atmospheric nitrogen (N₂) cannot be directly used by most organisms, but soil bacteria can convert it into a form that can be used by plants. This process is called nitrogen fixation. The fixed nitrogen can then be taken in by plant roots and used in various biological processes within the ecosystem. Option A is incorrect because photosynthesis primarily involves the uptake of carbon dioxide, not nitrogen. Option C and D are also incorrect because plants do not uptake elemental nitrogen directly; it has to be fixed by bacteria or other means first.

All Living Things Need Nitrogen