In Much of the Open Ocean, NPP Is Limited by Nitrogen.But

question 173

Multiple Choice

In much of the open ocean, NPP is limited by nitrogen.But in the Gulf of Mexico, especially near the mouth of the Mississippi River, dead zones (regions of low or no oxygen, resulting in the death of marine organisms) form every summer.These dead zones result from

• A) eutrophication caused by nitrogen fertilizer runoff from farms upstream.
• B) very low nitrogen levels leading to inability of plants to reproduce.
• C) an unknown combination of excess nutrients poisoning the system.
• D) a lack of required nutrients, with the type of nutrient varying from year to year.
• E) fertilizer production in the area producing smog, which limits photosynthesis.

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Intermediate Goods

Goods used to produce other goods.

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A gauge that tracks the overall variation in prices urban consumers pay for a selection of consumer products and services over a period.

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A reference year used in economics for comparative purposes, allowing the calculation of index numbers or real values.

Consumer Price Index

An index measuring the weighted average of prices of a basket of consumer goods and services, such as transportation, food, and medical care.