Review the image(s) and answer the following questions.

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1			Why are birds shown at the top of this food chain as being susceptible to high concentrations of DDT?
			A)	Birds are at the top of every aquatic food chain.
			B)	Birds consume fish at all levels of aquatic food chains.
			C)	DDT made the eggshells of predatory birds very fragile, and their population sizes plummeted, leading to a ban of DDT in the United States.
			D)	There is no significance to showing birds at the top of this food chain.
2			Why does DDT magnify within food chains when certain other chemicals do not?
			A)	DDT is more toxic.
			B)	DDT is stored in animal fat and is not readily eliminated from the body.
			C)	DDT is now present in great quantities in most natural habitats.
			D)	All of these are correct.

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3			Why do rain shadows exist on the lee side of mountain ranges?
			A)	As air descends on the lee side of a mountain range, its moisture-holding capacity increases and it picks up moisture rather than releasing it.
			B)	It is too far from an ocean to hold moisture long enough to drop it in the area of a rain shadow.
			C)	Soils are too thin in these regions to hold moisture, so none is available for evaporation.
			D)	These areas are generally very cold, and all water is frozen, and thus not available for evaporation.
4			In the western United States, most rain shadows occur on what side of the mountain ranges?
			A)	west
			B)	south
			C)	north
			D)	east

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5			Why does high altitude appear to limit the distribution of certain types of plants?
			A)	thin atmosphere at high altitudes
			B)	freezing year-round temperatures at high altitudes
			C)	too much rock, not enough soil
			D)	no animals available for pollination of flowers
6			Is it feasible to find tundra at the top of tall mountain peaks in a subtropical region?
			A)	It is unlikely, because only subtropical biomes occur in subtropic regions.
			B)	Yes, the distribution of biomes is mostly random, and tundra could occur as indicated.
			C)	Yes, biomes that occur far north and south of the equator also occur at high elevations.
			D)	No, there are no mountains in the world's subtropical regions.

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7			What one trait is common in organisms in the ocean deep that is rare elsewhere in the biosphere?
			A)	bioluminescence
			B)	heterotrophy
			C)	chemoautotrophy
			D)	commensalism
8			Of the ocean zones depicted, which is the most productive?
			A)	benthic zone
			B)	littoral zone
			C)	neritic zone
			D)	All are equally productive.