What limits productivity in polar regions?
A) low temperatures of the surface waters
B) the lack of sunlight year round
C) The thermocline acts as a barrier to mixing of surface and deep waters.
D) high density of the surface waters
E) all of the above
B
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Which of these pairs of processes, working together, will make the atmosphere most unstable?
A) warm the surface and cool the air aloft B) cool the surface and cool the air aloft C) cool the surface and warm the air aloft D) warm the surface and warm the air aloft
Which best describes areas with extremely high concentrations of rare plant and animal species that are in danger of extinction without immediate protection?
A. biodiversity hot spots B. Wi-Fi hot spots C. gardens in urban areas D. biodiversity cool spots
The movement of water through a cell membrane from a region of high concentration to a region of low concentration is called ____
A) diffusion B) osmosis C) active transport D) chemosynthesis
The amount of freshwater available compared to the amount used for human purposes is described by a measure called ____.
A. virtual water B. reliable surface runoff C. transpiration D. freshwater scarcity stress E. recharge