AP Environmental Science Flashcards: The Nitrogen Cycle
Written by AP Content Team, Verified for 2026 AP Exams, Last updated: May 2026
Review key ideas with interactive flashcards. This set includes 11 cards to help you master important concepts.
A scientist notes that a specific nitrogen reservoir empties and refills quickly. Is this observation consistent with the general principles of the nitrogen cycle?
Yes, this is consistent, as most reservoirs in the nitrogen cycle hold nitrogen compounds for relatively short periods of time.
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A scientist notes that a specific nitrogen reservoir empties and refills quickly. Is this observation consistent with the general principles of the nitrogen cycle?
Yes, this is consistent, as most reservoirs in the nitrogen cycle hold nitrogen compounds for relatively short periods of time.
What is the relationship between the atmosphere and nitrogen fixation?
The atmosphere serves as the major reservoir of nitrogen that is converted into usable forms for plants during the process of nitrogen fixation.
What is the nitrogen cycle?
The nitrogen cycle is the movement of atoms and molecules containing the element nitrogen between sources and sinks.
Why can't plants directly use the nitrogen from the atmosphere, its largest reservoir?
Plants cannot directly use atmospheric nitrogen because it must first be converted into an available form, like ammonia, through the process of nitrogen fixation.
What is a 'reservoir' in the context of the nitrogen cycle?
A reservoir is a source or sink where nitrogen compounds are held; the atmosphere is the major reservoir.
How long do nitrogen compounds typically stay in most reservoirs?
Most reservoirs in which nitrogen compounds occur hold those compounds for relatively short periods of time.
What is the major reservoir of nitrogen?
The atmosphere is the major reservoir of nitrogen.
Define nitrogen fixation.
Nitrogen fixation is the process in which atmospheric nitrogen is converted into a form (primarily ammonia) that is available for uptake by plants.
What is the main purpose of nitrogen fixation for plants?
The purpose of nitrogen fixation is to convert atmospheric nitrogen into a form, like ammonia, that is available for uptake by plants.
What is the primary chemical product of nitrogen fixation?
The primary product of nitrogen fixation is ammonia, a form of nitrogen that is available for uptake by plants.
Describe the core interaction within the nitrogen cycle.
The core interaction is the movement of nitrogen-containing atoms and molecules between different sources and sinks, such as the atmosphere and plants.