Which of the following best describes why DDT is classified as a persistent organic pollutant?
DDT is very stable, and as much as 50% of the original concentration can remain in the soil 15 years after the initial application.
Which of the following best describes a way that persistent organic pollutants (POPs) cause harm in the environment?
Persistent organic pollutants are soluble in fat, so they accumulate in an organisms’ fatty tissues.
Which of the following best explains why top predators can have up to 60 times as much of persistent organic pollutant (POP) as their prey and up to 600 times as much of the pollutant as producers?
POPs accumulate in the body fat of living organisms. POPs increase in concentration as they move up the food chain.
Mercury concentrations were measured in freshwater shrimp populations in two different ponds, one polluted with mercury and one unpolluted, with a similar food web in each pond. Which of the following best identifies the scientific question that would guide this investigation?
How much mercury accumulates in the tissues of freshwater shrimp living in a polluted pond?
A scientist is studying PCBs in tertiary consumers. She wants to determine if PCBs can be found in tertiary consumers even though these compounds were banned in the United States in the 1970s. Which of the following best identifies a testable hypothesis for the study?
PCBs are persistent organic compounds that are fat-soluble, so they should be found in the fatty tissues of tertiary consumers even though the compounds have been banned for decades.
Scientists are interested in determining if selenium, from a nearby mine, magnifies in the tissues of fish living in a lake. Which of the following best describes a testable hypothesis for the study?
Selenium will be at a higher concentration in fish tissue than in the tissue of fish prey.
Incineration is one solution to reduce the volume of municipal solid waste. Municipal solid waste can be used to produce energy at waste-to-energy plants. Based on the data in the graphs, which of the following materials would be best suited for incineration to reduce total volume, produce energy, and have minimal release of air pollutants?
Wood
Based on the data in the graphs, which of the following would result in the largest reduction in volume of municipal solid waste disposed of in landfills?
Introduce composting programs for yard trimmings and food waste
Based on the data in the graphs, which of the following strategies would best increase the total volume of municipal solid waste being recycled?
Enacting a single-stream recycling program and providing bins to residential homes
Based on the diagram, which of the following best describes how a malfunctioning air compressor would affect the process of sewage treatment?
Fewer bacteria would be available to absorb dissolved organics in the tank.
Based on the diagram, which of the following is associated with the primary treatment of sewage?
Grit chamber
Which of the following components, which are not shown on the diagram, are part of the tertiary treatment of wastewater?
Disinfectants
If all four of the bacteria species shown in the graph are equally likely to contaminate agricultural products at a dose of 102 CFU, regulating which of the following species would have the greatest effect in reducing the likelihood of illness in humans?
Salmonella spp.
Some drinking water standards allow bacteria in water at dosages up to the 10% probability of illness. Which of the following statements is best supported by the data in the graph?
The newly discovered bacterium would have the lowest allowable dosage to meet the drinking water standards.
An individual is exposed to the water in the stream from which the sample show in the graph was taken. If the individual was exposed to the highest dose of the bacteria, which of the following bacteria would have the lowest probability of causing illness if ingested?
C. jejuni
The LD50 for arsenic in humans is 13mg/kg. Which of the following approaches should be used to calculate the number of grams of arsenic it would take to reach the LD50 in a 140-pound person? [Note: 1kg=2.2pounds]
140 lb X 1kg/2.2lb X 13mg/1kg X 1g/1,000mg
A pesticide was applied to a population of roaches, and it was determined that the LD50 was 55mgkg. If the average mass of a roach was 0.02kg, which of the following approaches will determine the dose in mg per roach?
55mg/1kg X 0.02 kg
Based on the data in the graph, which of the following should be used to calculate the difference in LD50 for the two different species of mice?
575 mg - 490 mg
Water from which of the following locations on the map would best serve as a control group for the study?
A
Researchers suspect that sewage leaked into the Moose River. Rates for which of the following diseases should be used to determine whether the human population using the river as a source of drinking water was exposed to sewage?
Dysentery
Which of the following water quality tests would best indicate if sewage from the wastewater treatment plant has contaminated the Moose River?
Fecal coliform measured at site B
Based on the diagram, which of the following is the most likely reason that a community with good sanitation could still have individuals who contract cholera?
Runoff from a nearby agricultural field pollutes a reservoir used for drinking water.
Based on the diagram above, which of the following best describes why a population in an area that has poor sanitation can be particularly at risk for a cholera outbreak?
The bacterium that causes cholera is spread through ingestion of contaminated water or food.
Based on the diagram above, which of the following is the most likely reason that V. cholerae can spread rapidly through a population?
V. cholerae is a microscopic bacterium that can survive in various aquatic environments for prolonged periods of time and can cause a delayed onset of visible symptoms.