Nitrifying bacteria participate in the nitrogen cycle mainly by a. converting nitrogen gas to ammonia. b. releasing ammonium from organic compounds, thus returning it to the soil. c. converting ammonium to nitrate, which plants absorb. d. incorporating nitrogen into amino acids and organic compounds.

Verified step by step guidance

1. Identify the role of nitrifying bacteria in the nitrogen cycle. Nitrifying bacteria are known for their specific function in the nitrogen cycle.
2. Understand the process of nitrification. Nitrification involves the oxidation of ammonium (NH4+) into nitrite (NO2-) and then into nitrate (NO3-).
3. Match the process of nitrification to the correct answer choice. Since nitrifying bacteria convert ammonium to nitrate, look for the option that mentions this transformation.
4. Review the answer choices and find which one correctly describes the conversion of ammonium to nitrate. This is the key function of nitrifying bacteria in the nitrogen cycle.
5. Select the correct answer: c. converting ammonium to nitrate, which plants absorb.

Key Concepts

Nitrogen Cycle

The nitrogen cycle is a biogeochemical process that describes the transformation and movement of nitrogen through the atmosphere, soil, and living organisms. It involves several key steps, including nitrogen fixation, nitrification, denitrification, and ammonification, which collectively ensure the availability of nitrogen in forms usable by plants and animals.

Nitrification

Nitrification is a two-step microbial process in the nitrogen cycle where ammonia (NH3) is first oxidized to nitrite (NO2-) by ammonia-oxidizing bacteria, and then nitrite is further oxidized to nitrate (NO3-) by nitrite-oxidizing bacteria. This process is crucial as nitrate is a primary form of nitrogen that plants can readily absorb and utilize for growth.

Role of Nitrifying Bacteria

Nitrifying bacteria are specialized microorganisms that facilitate the conversion of ammonia into nitrate during nitrification. They play a vital role in maintaining soil fertility and ecosystem health by ensuring that nitrogen, an essential nutrient for plant growth, is available in a form that plants can uptake, thus supporting agricultural productivity and natural ecosystems.