9. The chemistry of aquatic ecosystems is determined bythe a. Amount of sats, nutrients, and oxygen dissolved in the water. b. Number of organisms present in the water. C. Amount of rainfallthe water receives. d. Biotic and abiotic factors in the water.

Allof the following statements concerning oligotrophic lakes are true, except:a.warm temperatures.b.low nutrients.c.high oxygen content.d.deep and clear waters.e.low biological productivity.

Which one of the following is not an ecosystem function? O A. The amount of plant growth that occurs in a particular year O B. Dead animals being consumed by bacteria and fungi OC. Timber production D. Phosphorous movement from rocks to organisms O E. All of these are ecosystem functions

4.6

Aquatic biomes are distinguished primarily by   a. their temperatures.   b. the speed of their currents.   c. their salinity.   d. their pH.

Clean liquid freshwater is quite limited. Droughts are predicted to OA. Decrease; cities OB. Increase; agriculture OC. remain the same; cities OD. increase; cities OE. Decrease; agriculture in length. The major consumer of freshwater is

Name the three main loopsof the hydrologic cycle. Then, describe how each of the three main loops operates to purify water in the biosphere. (Tell what happens in each loop that purifies the water.)

tend to occupy the base of food webs. a. mediatrophs O b. trophytrophs С. heterotrophs O d. autotrophs

A key feature of estuaries is: a. low light conditions and high productivity b. salt water and fresh water c. frequent algal blooms d. little or no vegetation

What have humans done to impact the water cycle? Oa. Removing vegetation which increases runoff & decreases infiltration and transpiration O b. Burning fossil fuels creating acid rain & contributing to ocean acidification OC. Depleting groundwater aquifers thus lowering the water table. Od. Damming rivers slows the movement of water & leads to increased evaporation from reservoirs O e. All of these