The Phosphorus Cycle

Which of the following is NOT true of phosphorus and the phosphorus cycle?

• Phosphorus is mined from phosphorus rich rock, which is processed and then added to commercial inorganic fertilizers as well as detergents.

• Phosphorus tends to be more localized compared with other biogeochemical cycles that can move more freely in the global system.

• Phosphorus is generally found in rocks, sediments, and soil.

• Phosphorus does not exist in the atmosphere as a gas.

• Living organisms do not need phosphorus.

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NGSS.MS-LS2-3

Phosphorus is mainly found (stored) in the atmosphere.

• True

• False

Both Phosphorus and Nitrogen are limiting nutrients in aquatic environments. Nitrogen tends to be limiting in marine environments while Phosphorus tends to be limiting in freshwater environments. When added to aquatic ecosystems, nitrogen and phosphorus can result in a hypoxic environment. This process is called:

• Biomagnification

• Cultural Eutrophication

• Bioaccumulation

• Upwelling

• Sedimentation

Which of the following is NOT a primary reservoir or sink for the element or molecule listed?

• Carbon -- Coal

• Nitrogen -- Atmosphere

• Phosphorus -- Sediments and Rock

• Sulfur - Deep Ocean Deposits

• Water -- Lakes and Rivers

Phosphorus is being added to the environment by all of the following activities EXCEPT

• runoff from feedlots and waste lagoons

• clear-cutting tropical habits for agriculture, thereby decreasing the amount of available phosphorus contained in vegetation.

• discharge from municipal sewage plants

• burning of coal and fossil fuels

• mining of phosphorus to produce inorganic fertilizers and detergents

The major sink for phosphorus is

• sedimentary rock

• atmospheric gases

• seawater

• plants

• animals

What is probably the principal source of nitrates and phosphates for living things?

• The water cycle

• Nitrogen fixation and lightning

• Decomposition by fungi and bacteria

• Changes in environmental temperature

• Changes in light intensity

Which of the following elements is most likely to limit primary production in freshwater lakes?

• Oxygen

• Calcium

• Phosphorus

• Carbon

• Iron

Phosphorus

• is a limiting nutrient in many freshwater ecosystems.

• has an important gaseous phase

• is easily lot from soils due to leaching

• is often produced by volcanic eruptions

• changes chemical form often during its biogeochemical cycle