Which processes are involved in nutrient cycling in a functioning ecosystem?
Which processes are involved in nutrient cycling in a functioning ecosystem?
- A. Erosion, weathering, and sedimentation
- B. Decomposition, evaporation, and precipitation
- C. Nitrogen fixation, denitrification, and ammonification
- D. Respiration, photosynthesis, and transpiration
Correct Answer: C. Nitrogen fixation, denitrification, and ammonification
Explanation
Nitrogen fixation: This process involves the conversion of atmospheric nitrogen gas (N2) into a usable form, such as ammonium (NH4+), by nitrogen-fixing bacteria or through lightning. This makes nitrogen available for plants and other organisms.
Denitrification: Denitrifying bacteria convert nitrates (NO3-) back into atmospheric nitrogen gas (N2), completing the nitrogen cycle. Denitrification occurs under anaerobic conditions, such as in waterlogged soils or sediments.
Ammonification: Ammonification is the process by which decomposers, like bacteria and fungi, break down organic nitrogen compounds from dead organisms and waste products into ammonium (NH4+). This ammonium can then be used by plants and other organisms.