APES UNIT 8

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?

55mg1kg×0.02kg

The graph below shows the dose response curves for four different chemicals, labeled A — D, in a dose-response study on the effects of the chemicals on mortality in amphibians. All dose experiments began at 0 units of each chemical. Based on the data in the graph, which of the four chemicals is the most toxic to amphibians regardless of dose?

A

Which of the following correctly identifies both a nonpoint source and a point source of pollution?

D

Which of the following components, which are not shown on the diagram, are part of the tertiary treatment of wastewater?

Disinfectants

Which of the following best describes the action of endocrine disruptors in organisms?

Endocrine disruptors mimic naturally occurring hormones in animals, leading to developmental disorders.

Which of the following strategies will best help to protect mangrove habitats?

Limiting coastal development and maintain a shoreline buffer zone

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.

Based on the data in the table, which of the following concentrations of sodium chloride is most toxic to brine shrimp?

0mg100mL/

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]

140lb×1kg2.2lb×13mg1kg×1g1,000mg

The graph below shows the LD50 for two different species of mice after being exposed to a mutagen for 30 days. 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?

575mg - 490mg

A scientist investigated the radiation sensitivity of different mammals to x-rays to determine the LD50 within 30 days. Results from the study are included below. Based on the LD50 data in the table, which of the following equations should be used to calculate how many times greater the resistance of a rabbit to x-rays is than that of a dog?

800/325

Researchers are evaluating the waste treatment facility located on the Moose River in the northeastern United States. They are sampling the river and its tributaries at several locations, as shown on the map below. Water from which of the following locations on the map would best serve as a control group for the study?

A

A scientist wanted to investigate the effect of tropospheric ozone on the respiratory function of mice. Twenty female mice were placed in one of five different field environments that mimicked the natural habitats of the mice. Each environment had a tube connected to it that would pump in a set level of ozone measured in ppm. In each field environment, the scientist measured the average respiratory output for the twenty mice over a three-month time frame. Which of the following should be added to the study to best serve as the control group?

A group of twenty mice that were not exposed to ozone

Which of the following is an example of a point source of pollution?

A leaking septic tank

Which of the following best describes the action of an endocrine disruptor?

An endocrine disruptor blocks the receptor protein binding site of a hormone so that the cell cannot receive a signal.

A biologist is studying a small food web in which phytoplankton are eaten by krill, krill are eaten by fish, and fish are eaten by seals. During their study of the ecosystem, the biologist discovers that PCBs are present in measurable levels in the water and wants to examine how PCBs could vary in different trophic levels. Which of the following best identifies a testable hypothesis for the study?

Biomagnification will cause the seals to have the highest amount of PCBsPCBs in their tissues.

At what step in the diagram would the last solid waste be removed from the wastewater in the treatment plant?

C

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

Which of the following approaches would best decrease the impact of frequent flooding in a community that is subject to the hazard of flooding?

Construct wetland areas near the rivers and streams.

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 the source of persistent organic pollutants (POPs) that could accumulate in the tissues of a top predator?

DDTDDT and other pesticides that are sprayed to control for mosquitoes

Which of the following is the most likely impact of thermal pollution from power plants on a river ecosystem?

Decreased oxygen levels because warm water holds less dissolved gas than cold water does

Based on the diagram, which of the following is an expected consequence of runoff and sewage in an aquatic environment?

Decreased oxygen production by seaweed on the seafloor from an increase in turbidity

Scientists are interested in studying the bioaccumulation of mercury in different species of dolphins exposed to the same concentration of mercury. The dolphins in the study will be of similar age and living in the same habitat. Which of the following best identifies a testable hypothesis for the study?

Different species of dolphins will have different levels of mercury in their fatty tissues depending on the species' ability to absorb and excrete mercury.

Based on the pathways shown in the diagram, which of the following best describes how climate change will most likely increase the transmission rates of the Zika virus?

Expanded mosquito ranges will increase human exposure to the virus.

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

Which of the following examples includes both a point and a nonpoint source of pollution?

Fertilizer from suburban lawns and wastewater from a water treatment plant

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

Endocrine disruptors directly affect which of the following in an organism?

Hormones

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?

Which of the following is the most likely consequence of runoff transporting chemicals that are endocrine disruptors to a pond?

Increased frequency of birth defects in fish populations in the pond

Based on the data in the graph, which of the following solutions most likely led to the decrease in the amount of waste sent to landfills from 1990 to 2015 ?

Increased recycling of waste

Which of the following is a way to potentially eliminate one of the greatest threats to the world's mangrove wetlands?

Integrate ecologically sound shrimp aquacultural practices with mangrove management.

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 diagram, which of the following is the vector that transmits the Zika virus to humans?

Mosquitoes

A scientist is studying the correlation between air pollution and cardiovascular disease in humans. Which of the following measures would best show a link between air pollution and cardiovascular disease?

Occurrences of emergency room visits by individuals with cardiovascular disease on days with a high air quality index value

A beach community was recently negatively affected by a hurricane. Community leaders are looking for a potential solution to prevent damage from future hurricanes. Below is a list of their concerns as well as how important each issue is to the community. Which of the following solutions would best address the issues of greatest concern in the community?

Planting mangrove forests

The diagram below depicts a surface water source that has undergone cultural eutrophication. Based on the diagram, which of the following processes most likely caused the algal bloom in the lake?

Runoff carried excess fertilizer from the cornfield into the water.

Cholera is an acute infection of the digestive system that is caused by the bacterium Vibrio cholerae. Infected individuals can experience a range of symptoms, including diarrhea, vomiting, muscle cramps, low blood pressure, rapid heart rate, and extreme thirst. If symptoms persist and severe dehydration results, an infected individual can die within hours of symptom onset. The diagram below shows how cholera is transmitted. 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, organic solids that have settled to the bottom of the treatment tanks in step B are transferred to which of the following for further processing?

Sludge treatment tanks

Which of the following statements best describes how the Clean Water Act legislation aims to protect wetlands from being lost?

The Clean Water Act requires wetlands to be constructed to mitigate the effect of newly drained wetlands.

Based on the diagram, which of the following processes most likely caused the bottom-dwelling plants in the lake to die?

The algal bloom prevented sunlight from reaching the bottom-dwelling plants, which reduced the rates of photosynthesis.

A massive bluegill fish kill was observed in a lake near a power plant during the winter months. It was determined that the plant was releasing large amounts of hot water into the lake. Which of the following explains what likely caused the death of so many bluegills in the lake?

The influx of warmer water caused an unexpected increase in the metabolic rate of the bluegills, which led to increased physiological stress from limited resource availability.

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.

Based on the diagram, which of the following processes most likely caused the fish in the lake to die?

The remains of the bottom-dwelling plants and algae decomposed, depleting the amount of oxygen in the water.

The two pie charts show municipal solid waste (MSW) in the United States, 2015. 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; Compared to the other choices, wood does not make up the largest percentage of MSW, but it is the best candidate for incineration because it is easily combustible and has less harmful air pollutants than other materials.

Significant increases in water temperature can drastically change dissolved oxygen (DO) levels in a lake. Why does the combined effect of these two environmental changes result in algal blooms?

Low dissolved oxygen leads to death for aerobic organisms, like fish, whose decomposition provides an overabundance of nutrients for the algae, resulting in the large blooms.

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

Which of the following practices would best help to protect against inland and coastal flooding in urban areas?

Preserving wetland and coastal mangrove habitats

Which of the following would best be described as a point source of pollution from a farm?

Runoff from the waste lagoons of Concentrated Animal Feeding Operations, which enters local waterways after a flooding event

The graph below depicts the dose response curves for three common bacteria and a newly discovered bacterium found in streams near certain agricultural properties. 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 .

When water used to cool power plants during normal plant operations is released into adjacent waterways, which of the following is most likely to occur as a result?

The dissolved oxygen in the adjacent waterways would decrease because used coolant water is warm and leads to thermal pollution.

Based on the image, which of the following conclusions can best be drawn to describe the conditions in the Long Island Sound?

The sound has large numbers of phytoplankton blooms that are decomposing and consumed by respiring bacteria.

One benefit of solid waste disposal in landfills is that the methane produced from decomposition can be harnessed for energy. Based on the data in the graph, methane production from waste management most likely peaked during which of the following years?

1990

A scientist wants to study the effect of DDT in a fish-eating bird species. She measures a variety of variables in a population of birds over a period of ten years to determine how levels of DDT affect bird survival and reproduction. Which of the following identifies a scientific question she could ask to best evaluate the effect of DDT on the bird species?

Does the persistence of DDTDDT lead to eggshell thinning or developmental deformities in the bird species?

At what step in the diagram would wastewater most likely be treated with chlorine or UV light to remove bacteria?

During step D

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

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

Which of the following pollutants would most likely be responsible for gender imbalance in a population of frogs in which all observed frogs are female?

Endocrine disruptors

Which of the following is a point source pollutant that would likely affect the ecosystem health of a coral reef?

Excess nutrients introduced by fertilization of farmland

Based on the data in the graph, which of the following likely occurred from 1960 to 2015 because of changes in solid waste disposal methods?

Fewer natural resources needed to be extracted.

Based on the diagram, which of the following is one way that the Zika virus can be spread within the human population?

From a mother to her unborn child

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

According to the World Health Organization, persistent organic pollutants (POPs) are found in nearly all tested organism tissues and environmental samples. Which characteristic of POPs accounts for their presence in living tissues and in environmental samples?

POPsPOPs are released in to the air, water, and land, which allows them to be transported and incorporated in multiple ways.

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 correctly identifies an example of an endocrine disruptor and the effect it might have on the human body?

Phthalates in cosmetics and shampoos reduce fertility.

Long Island Sound is a body of water off the northeast coast of the United States. Over nine million people live in the small watershed area that feeds into the sound. To determine the effect of the population density on the watershed, scientists measured the oxygen content of bottom waters in the sound. The data from late summer 2013 are displayed in the map below. Which of the following factors would most likely contribute to the conditions observed in the Long Island Sound?

Restricted circulation; The enclosed shape of the sound could result in reduced circulation, meaning that oxygen-rich waters would not reach bottom waters where phytoplankton do not photosynthesize. The shape could also prevent water movement from increasing the amount of oxygen in the water. This is the most likely factor to contribute to the hypoxic conditions in the sound.

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; This is depicted in steps 3 and 4 of the diagram. In areas with poor sanitation, it is more likely that water sources contaminated with the bacteria are used for bathing, drinking, and food preparation. Without proper water treatment, more individuals would be infected with the disease.

The table below shows the number of brine shrimp that hatched over 72 hours in three different concentrations of salt water. All tanks had 50 eggs at the start of the study. Which of the following claims about brine shrimp is best supported by the data in the table?

The optimal salinity for brine shrimp hatching is 30mg100mL30mg100mL.

A small lake, located downstream of a power plant, recently experienced a die-off of multiple aquatic species. Environmentalists had been monitoring the temperature of the lake for several months prior to the die-off and noticed a significant spike in the temperature of the lake immediately preceding the die-off event. Which of the following best explains why the die-off event occurred in the lake following the increased water temperature?

The warm water decreased the amount of dissolved oxygen in the water, which led to an increase in the respiration rate of the aquatic organisms.

Which of the following best describes why persistent organic pollutants (POPs) are toxic to organisms?

They do not break down easily and can accumulate in the fat tissue of an organism.

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.

Which of the following best describes how thermal pollution from power plants can affect aquatic ecosystems?

Warm water discharged into rivers and streams decreases the oxygen content of the water, which reduces the number of fish species.

A scientist wanted to investigate the effect of tropospheric ozone on the respiratory function of mice. Twenty female mice were placed in one of five different field environments that mimicked the natural habitats of the mice. Each environment had a tube connected to it that would pump in a set level of ozone measured in ppm. In each field environment, the scientist measured the average respiratory output for the twenty mice over a three-month time frame. Which of the following describes the independent variable in the experiment?

The different levels of ozone introduced into the environments