Choose the best answer. What made the cleanup of Chesapeake Bay difficult? I. The companies that polluted it were no longer in business. II. The bay's watershed is large and encompasses several states. III. Tides and currents impeded the cleanup work. (a) I only (b) II only (c) III only (d) I and II

Choose the best answer. A group of researchers monitored the health of all streams in a single watershed Several streams in one region of the watershed had a high silt content, large boulders, and a low diversity of insects and fish. What would be the most direct inference from this description? (a) Most of the sediment load in the stream is probably from a natural source. (b) The surrounding area probably has a high amount of impervious surface. (c) There is probably a high biochemical oxygen demand in the benthos of the stream. (d) The streams have very low resilience.

Choose the best answer. Which is NOT an example of a consequence of biomagnification? (a) incidences of human cancer associated with spraying crops with pesticides (b) suffocation of fish as a result of inert pesticide ingredients (c) thinning of bird egg shells (d) increasing concentrations of iron at higher levels of a food chain

Choose the best answer. Which mineral is ultimately responsible for the yellow color of streams that drain from abandoned mines? (a) pyrite rock (b) aluminum (c) coal (d) sulfur

Choose the best answer. You want to conduct a natural experiment to test whether leakage from a manure lagoon has an adverse effect on a nearby stream. What is an appropriate null hypothesis for your experiment? (a) There wall be a higher abundance of an indicator species in the stream before the lagoon began leaking than after it began leaking. (b) There will be a lower abundance of an indicator species in the stream before the lagoon began leaking than after it began leaking. (c) There will be no difference in the abundance of phytoplankton in the stream before the lagoon began leaking and after it began leaking. (d) There will be no difference in the abundance of an indicator species in the stream before the lagoon began leaking and after it began leaking.

Choose the best answer. In the northeastern United States, during what time(s) of the year are lakes located near agricultural fields in temperate ecosystems most likely to experience the highest biochemical oxygen demand? (a) throughout the entire growing season (b) primarily during the spring (c) primarily during the summer (d) during the fall

Choose the best answer. Which is NOT a problem that results from the use of pesticides? (a) Most pesticides are not target-specific and kill other related and nonrelated species. (b) Pesticide runoff enters surface waters and increases the solubility of heavy metals. (c) Pesticides target specific physiological functions, but also disrupt other functions. (d) Most inert ingredients are not tested for safety and may pose unacceptable risks.

Choose the best answer. Acid mine drainage occurs when acidic water formed belowground makes its way to the surface; the acidic water is formed in flooded abandoned mines where the underground water (a) reacts with a type of rock, pyrite, which releases iron and hydrogen ions. (b) reacts with sulfur dioxide and nitrogen dioxide to form sulfuric and nitric acids. (c) flushes out the chemicals used in the mining process. (d) permeates a limestone layer that lowers the pH.

Choose the best answer. Which inorganic substance is naturally occurring in rocks, soluble in groundwater, and toxic at low concentrations? (a) mercury (b) lead (c) PCBs (d) arsenic

Choose the best answer. Under which circumstance is a sewage treatment plant legally permitted to bypass normal treatment protocol and discharge large amounts of sewage directly into a lake or river? (a) when the population of the surrounding community surpasses the plant's capacity (b) when combined volumes of storm water and wastewater exceed the capacity of an older plant (c) when a permit to modernize the plant is denied by the Environmental Protection Agency (d) when an extended period of drought restricts water flow in a lake or river

Choose the best answer. Both septic systems and sewage treatment plants utilize bacteria to break down organic matter. Where in each system does this process occur? (a) septic tank and leach field; primary treatment and secondary treatment (b) septic tank only; primary treatment and chlorination (c) leach field only, secondary treatment only (d) septic tank and leach field; secondary treatment only

Choose the best answer. Tertiary treatment of wastewater (a) removes pathogens. (b) reduces sediment. (c) reduces eutrophication. (d) reduces the amount of sludge.

Acid mine drainage occurs when acidic water formed belowground makes its way to the surface; the acidic water is formed in flooded abandoned mines where the underground water (a) reacts with a type of rock, pyrite, which releases iron and hydrogen ions. (b) reacts with sulfur dioxide and nitrogen dioxide to form sulfuric and nitric acids. (c) flushes out the chemicals used in the mining process. (d) permeates a limestone layer that lowers the pH. (e) reacts with copper and aluminum to form pyrite rock and hydrogen ions.

Choose the best answer. Which indicates that a body of water is contaminated by human wastewater? (a) low BOD and a fecal coliform bacteria count of zero (b) high levels of nutrients, such as nitrogen and phosphorus, and high BOD (c) low BOD and low levels of nutrients, such as nitrogen and phosphorus (d) low levels of nutrients, such as nitrogen and phosphorus, and a fecal coliform bacteria count of zero