Which of the following is one of the key components of the nitrogen cycle?

• A. Photosynthesis
• B. Glycolysis
• C. Transcription
• D. Nitrogen fixation

Answer: (D)

Verified step by step guidance

1. Understand the nitrogen cycle: The nitrogen cycle is a biogeochemical process that describes how nitrogen moves through the atmosphere, soil, water, and living organisms. It includes processes like nitrogen fixation, nitrification, assimilation, ammonification, and denitrification.
2. Identify nitrogen fixation: Nitrogen fixation is the process by which atmospheric nitrogen (N₂), which is inert and unusable by most organisms, is converted into ammonia (NH₃) or related compounds that can be used by plants and other organisms.
3. Recognize the role of nitrogen fixation: Nitrogen fixation is primarily carried out by certain bacteria and archaea, either free-living in the soil or in symbiotic relationships with plants (e.g., Rhizobium bacteria in legume root nodules). These microorganisms use the enzyme nitrogenase to catalyze the conversion of N₂ into ammonia.
4. Compare the options: Photosynthesis, glycolysis, and transcription are unrelated to the nitrogen cycle. Photosynthesis is the process by which plants convert light energy into chemical energy, glycolysis is a metabolic pathway for breaking down glucose, and transcription is the process of synthesizing RNA from DNA.
5. Conclude that nitrogen fixation is the correct answer: Based on the explanation above, nitrogen fixation is a key component of the nitrogen cycle, as it allows atmospheric nitrogen to be converted into a form usable by living organisms.