Question

match the description to the steps of the nitrogen cycle.
a. nitrogen compounds (nitrites and nitrates) are re-converted and released back into the atmosphere.
b. ammonia is converted into nitrates by the presence of bacteria in the soil.
c. atmospheric nitrogen is converted to nitrogen compounds.

1. fixation.
2. nitrification.
3. denitrification.

Explanation:

• For option a: Denitrification is the process where nitrogen compounds (nitrites, nitrates) are converted back to atmospheric nitrogen, so a matches 3. Denitrification.
• For option b: Nitrification is the conversion of ammonia to nitrates by soil bacteria, so b matches 2. Nitrification.
• For option c: Fixation is the conversion of atmospheric nitrogen to nitrogen compounds, so c matches 1. Fixation.

Answer:

a. 3. Denitrification
b. 2. Nitrification
c. 1. Fixation