1). Over land, most of the water in the atmosphere results from ___________, whereas over the oceans, most of the water in the atmosphere results from ____________.
2). Which of the statements about groundwater is not accurate?
a). In the U.S., groundwater provides 50% of the population with drinking water.
b). Groundwaters are being depleted faster than they can be recharged.
c). Groundwaters are becoming increasingly polluted.
d). Removal of pollutants from groundwaters is easily achieved. [wp_campaign_1]
3). The largest store of carbon molecules on earth is in
a). the atmosphere.
b). fossil fuels.
c). marine sediments.
d). living organisms.
4). Some bacteria have the ability to “fix” nitrogen. This means
a). they convert ammonia into nitrites and nitrates.
b). they convert atmospheric nitrogen gas into biologically useful forms of nitrogen.
c). they break down nitrogen-rich compounds and release ammonium ions.
d). they convert nitrate into nitrogen gas.
5). The phosphorous cycle differs from the water, carbon, and nitrogen cycles in that
a). the reservoir for phosphorous exists in mineral form in rocks rather than in the atmosphere.
b). phosphorous is far more abundant than water, carbon, or nitrogen.
c). phosphorous is less important to biological systems than water, carbon, or nitrogen.
d). phosphorous, once used by an organism, does not cycle back to the environment.
6). In the Hubbard Brook experiments, which of the following situations did not occur?
a). The undisturbed forests were effective at retaining nutrients.
b). The deforested areas gained nitrogen.
c). The deforested areas lost more water to runoff than the undisturbed forests.
d). The deforested areas lost more minerals to runoff than the undisturbed forests.
7). What percentage of the energy that hits a plant’s leaves is converted into chemical (food) energy?
8). According to the trophic cascade hypothesis, the removal of carnivores from an ecosystem may result in
a). a decline in the number of herbivores and a decline in the amount of vegetation.
b). a decline in the number of herbivores and an increase in the amount of vegetation.
c). an increase in the number of herbivores and an increase in the amount of vegetation.
d). an increase in the number of herbivores and a decrease in the amount of vegetation.
9). Experimental evidence from the Cedar Creek Natural History Area supports the hypothesis that
a). species richness is related to community stability.
b). human activities are upsetting the trophic cascade.
c). bottom-up effects can regulate the number of top carnivores in a system.
d). some aquatic ecosystems have inverted biomass pyramids. [wp_campaign_2]
10). The equilibrium model of island biogeography suggests all of the following except
a). larger islands have more species than smaller islands.
b). the species richness of an island is determined by colonization and extinction.
c). smaller islands have lower rates of extinction.
d). islands closer to the mainland will have higher colonization rates.