unit 8 apes test
For a certain insecticide, the LD-50 dosage level for rats is determined to be 250 milligrams per kilogram of body mass. ON the basis of this information, which of the following is the best prediction regarding the consequences of receiving this dosage of the insecticide?
500 out of every one thousand rats would die
which of the following components of a waste water treatment plants designed to facilitate the decomposition of organic material by aerobic microorganisms?
Activated-sludge tank
Some toxic compounds are ingested and retained in the tissues. These pollutants pose special risks to humans and other organisms high on the food chain because of which process?
Biomagnification
If wastewater treatment plant effluent that contains nitrates and phosphates is allowed to flow into a body of water, which of the following may result?
Eutrophication
the presence of which of the following contaminants would be the strongest reason for judging municipal sewage sludge unfit for use as fertilizer?
Heavy metals
a chemical compound that can cause algal blooms and cultural eutrophication in streams
Nitrates
which of the following best describes a way that persistent organic pollutants ( ) cause harm in the environment?
Persistent organic pollutants are soluble in fat, so they accumulate in an organisms' fatty tissues.
referring to the graph above, some some studies have indicated that global amphibian populations are declining and that exposure to herbicides in agricultural runoff is implicated in the decline. Which of the following is the most likely explanation of how herbicides affect amphibians?
The herbicides act as endocrine disruptors
All of the following are commonly used to deal with the side effects of eutrophication in lakes EXCEPT
adding nitrates
eutrophication results in the death of trout and other fish as a result of
asphyxiation from lack of oxygen.
Major anthropogenic sources of nitrogen pollution include commercial fertilizers, vehicle exhaust, industrial air pollution, and
discharge of sewage to surface water
factors that increase the spread of infectious diseases include all of the following EXCEPT
exposure to neurotoxins, which affect the endocrine system
The use of nitrogen-based fertilizers in the Midwestern United States is a major contributing factor to which of the following?
hypoxia in the gulf of Mexico
Three common methods employed in the cleanup of oil spills are
large floating booms, skimmer boats, and genetically engineered bacteria
pose a health risk to humans who eat large quantities of marine fish such as swordfish and tuna
mercury
which of the following is the best example of a point source pollutants?
oil tanker spill
Lakes that are characterized by high water clarity and low concentrations of dissolved nutrients are classified as
oligotrophic
which of the following is an effective alternative to chlorine for disinfecting wastewater in a municipal treatment plant?
ozone
which of the following will result in accelerated eutrophication when introduced into streams, lake, and bays?
phospates
which of the following strategies will best reduce eutrophication in the Chesapeake Bay?
regulating the use of inorganic fertilizer in the Susquehanna River watershed
Waste from which of the following is an example of nonpoint source pollution?
runoff from agricultural field
which of the following best illustrates point-source pollution?
smokestack emissions from a large smelting company.
which of the following is true of sewage treatment plants in the United States?
they are not designed to remove pharmaceutical chemicals from wastewater
x
x
which of the following examples includes both a point and a nonpoint source of pollution?
fertilizer from suburban lawns and wastewater from water treatment plant