Even though nitrogen constitutes 78% of Earth's atmosphere,the amount available for living things nearly all comes from
A)a few groups of nitrogen-fixing bacteriA.
B)the breakdown of minerals.
C)a few genera of detritivores.
D)the breakdown of dead plants.
E)nitrogen-containing fertilizers.

Question

Quizplus · Accepted Answer

Nitrogen is an essential element for living organisms, but most organisms cannot use nitrogen in its atmospheric form. Nitrogen is fixed by certain bacteria in the soil, such as symbiotic bacteria on the roots of legumes and free-living bacteria in the soil. These bacteria convert atmospheric nitrogen into other forms such as ammonia, which can be used by plants to make proteins. Therefore, the amount of nitrogen available for living things comes from a few groups of nitrogen-fixing bacteria.

Even Though Nitrogen Constitutes 78% of Earth's Atmosphere,the Amount Available