Biogeochemical Cycles

Front

What is the most abundant gas in our atmosphere at 78%?

Back

Nitrogen

Front

What organisms found in the soil and roots of plants "fix" nitrogen through the process called nitrogen fixation?

Back

bacteria

Front

Can nitrogen be used directly from the atmosphere?

Back

No, it cannot be used directly.

Front

Process in which nitrogen can be fixed by lightning, bacteria, or industries.

Back

Nitrogen Fixation

Front

Process in which nitrifying bacteria change ammonia into nitrites and then nitrates so that plants can absorb the nitrogen.

Back

Nitrification

Front

Process by which animals obtain and digest nutrients by consuming plants or other animals.

Back

Assimilation

Front

Process by which decomposers break down dead plants and animals and return the nutrients to the soil.

Back

Decomposition

Front

Process by which nutrients are returned to the soil through waste products.

Back

Excretion

Front

Process by which nitrogen is returned to the soil as ammonia after decomposition.

Back

Ammonification

Front

Process by which bacteria convert nitrogen compounds in the soil back into atmospheric nitrogen.

Back

Denitrification