Which would happen if only nitrogen fixing bacteria were present in the soil?
A. Ammonia would build up in the soil
B. Oxygen would build up in the soil
C. Excessive plant growth would occur
D. Denitrification would occur
To determine which of the given options would happen if only nitrogen-fixing bacteria were present in the soil, we need to understand the role of nitrogen-fixing bacteria and its impact on the soil.
Nitrogen-fixing bacteria are microorganisms that convert atmospheric nitrogen gas (N2) into a usable form of nitrogen, such as ammonia (NH3) or nitrate (NO3-), through a process called nitrogen fixation. This process is essential because plants require nitrogen to synthesize proteins and other essential molecules.
Now let's analyze the answer options:
A. Ammonia would build up in the soil: This option is correct. Nitrogen-fixing bacteria convert nitrogen gas into ammonia during nitrogen fixation. If only nitrogen-fixing bacteria were present in the soil and there were no other processes to remove the excess ammonia, it would accumulate in the soil.
B. Oxygen would build up in the soil: This option is incorrect. Nitrogen fixation does not directly involve the accumulation of oxygen in the soil. Oxygen is usually present in the soil and is required for the survival of most organisms.
C. Excessive plant growth would occur: This option is incorrect. Excessive plant growth generally occurs when there is an abundance of essential nutrients, including nitrogen. However, the presence of only nitrogen-fixing bacteria ensures a limited supply of nitrogen, as these bacteria can only convert atmospheric nitrogen into usable forms.
D. Denitrification would occur: This option is incorrect. Denitrification is the process in which bacteria convert nitrate (NO3-) back into atmospheric nitrogen (N2). However, denitrification requires the presence of specific bacteria that can perform this conversion. Since only nitrogen-fixing bacteria are present in this scenario, denitrification would not occur.
Therefore, to answer the question, if only nitrogen-fixing bacteria were present in the soil, option A is correct: Ammonia would build up in the soil.