Question

In the nitrogen cycle, different forms of nitrogen move through all of Earth’s subsystems. Which step in the nitrogen cycle shows how nitrogen moves from the atmosphere to the geosphere?
A. Decomposers in soil break down dead organisms and release atmospheric nitrogen.
B. Nitrogen-fixing bacteria in the soil convert nitrogen from the air to make nitrates.
C. Plants obtain nitrates through their roots in a process called assimilation.
D. Animals get the nitrogen needed to grow by eating nitrogen-containing plants.

Answer 1

Answer:

B, that is, nitrogen-fixing bacteria in the soil convert nitrogen from the air to make nitrates.  

Explanation:

As we know, Nitrogen cycle hold alot of importance in earth's geology because it moves the Nitrogen from soil to the atmosphere and then back to the biosphere fulfilling the Nitrogen needs of animals as well as plants.

Just like all other biogeochemical cycles,  there are different stages of Nitrogen cycle through which an interchange of nitrogen between different reservoirs occur.

The Nitrogen present in the atmosphere is not usable for the animals and plants. However, there are some bacteria present in the soil called nitrogen-fixing bacteria that convert the atmospheric nitrogen to a usable form called nitrates. Plants are able to use these Nitrates and fulfill their nitrogen demands as nitrogen is the main component of the chlorophyll - molecule that makes photosynthesis possible.

Therefore B is the appropriate option.

Hope it help!