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AP Environmental Science Practice Quiz: The Phosphorus Cycle

Written by AP Content Team, Verified for 2026 AP Exams, Last updated: May 2026

Test your understanding with short quizzes. This quiz has 10 questions to check your progress.

Question 1 of 10

According to the provided text, the phosphorus cycle is best defined as the movement of phosphorus between which two components?

All Questions (10)

According to the provided text, the phosphorus cycle is best defined as the movement of phosphorus between which two components?

A) Producers and consumers

B) The atmosphere and the lithosphere

C) Sources and sinks

D) Living and nonliving things

Correct Answer: C

The provided content explicitly states, 'The phosphorus cycle is the movement of atoms and molecules containing the element phosphorus between sources and sinks.'

What are identified as the major reservoirs for phosphorus?

A) The atmosphere and oceans

B) Rock and sediments

C) Living organisms and fossil fuels

D) Soil and freshwater lakes

Correct Answer: B

The text clearly states, 'The major reservoirs of phosphorus are rock and sediments that contain phosphorus-bearing minerals.'

Which of the following is a key characteristic that distinguishes the phosphorus cycle from other major biogeochemical cycles like the carbon or nitrogen cycles?

A) It involves both living and nonliving components.

B) It is primarily driven by solar energy.

C) It does not have a significant atmospheric component.

D) It is the fastest of the nutrient cycles.

Correct Answer: C

The content specifies, 'There is no atmospheric component in the phosphorus cycle,' which is a major difference compared to the gaseous phases of the carbon and nitrogen cycles.

Based on the information provided, why is phosphorus often a limiting factor in many ecosystems?

A) Because it is quickly consumed by decomposers.

B) Because its major reservoirs in rock and sediment are not easily accessible.

C) Because it is highly soluble in water and washes away.

D) Because it lacks an atmospheric component, making it naturally scarce.

Correct Answer: D

The text directly links the absence of an atmospheric phase to its scarcity, stating, 'There is no atmospheric component in the phosphorus cycle, making it naturally scarce and a limiting factor...'

The movement of phosphorus from phosphorus-bearing minerals into an ecosystem is an example of an interaction between which of the following?

A) A major reservoir and a sink

B) The atmosphere and a source

C) Two different sinks

D) A consumer and a producer

Correct Answer: A

The text identifies 'rock and sediments that contain phosphorus-bearing minerals' as the major reservoirs. The movement of phosphorus from this reservoir into an ecosystem (a sink) is a key interaction in the cycle.

Which of the following best describes the primary state of phosphorus within its major reservoirs?

A) As a gas in atmospheric pockets

B) As dissolved ions in the ocean

C) As a component of minerals in rock and sediments

D) As organic matter in living organisms

Correct Answer: C

The content states that the major reservoirs are 'rock and sediments that contain phosphorus-bearing minerals,' indicating that its primary state in these reservoirs is as part of a mineral.

The term 'limiting factor' in the context of the phosphorus cycle implies that its availability can:

A) Increase the speed of the water cycle.

B) Constrain the growth of organisms in an ecosystem.

C) Create an atmospheric reservoir for other nutrients.

D) Be easily substituted by nitrogen or carbon.

Correct Answer: B

The content states phosphorus is a 'limiting factor in many aquatic and terrestrial ecosystems.' A limiting factor is a resource that restricts population size or growth, which in this case applies to the organisms within the ecosystem.

Given that the major reservoirs of phosphorus are rock and sediment and there is no atmospheric component, which of the following can be inferred about the phosphorus cycle?

A) It is a rapid cycle, with phosphorus moving quickly between sources and sinks.

B) Human activities have no significant impact on this cycle.

C) It is a relatively slow cycle, as the release of phosphorus from rock is a slow process.

D) Phosphorus is most abundant in the atmosphere compared to other nutrients.

Correct Answer: C

Because the primary reservoirs are geological (rock and sediments) and there is no fast-moving atmospheric phase for transport, the natural release of phosphorus is a slow geological process (like weathering), making the overall cycle very slow.

The phosphorus cycle describes the movement of which element?

A) Potassium

B) Phosphorus

C) Photosynthesis

D) Phytoplankton

Correct Answer: B

The provided content explicitly defines the phosphorus cycle as 'the movement of atoms and molecules containing the element phosphorus.'

Which statement is NOT supported by the provided text about the phosphorus cycle?

A) Phosphorus moves between sources and sinks.

B) The cycle includes a significant gaseous phase that allows for long-range transport.

C) The scarcity of phosphorus can limit ecosystem productivity.

D) Geological formations are the primary storage sites for phosphorus.

Correct Answer: B

The text explicitly states, 'There is no atmospheric component in the phosphorus cycle.' Therefore, the statement that it includes a significant gaseous phase is directly contradicted by the provided information.