2022 AP Environmental Science ® Free-Response Questions Set 1 © 2022 College Board. College Board, Advanced Placement, AP, AP Central, and the acorn logo are registered trademarks of College Board. Visit College Board on the web: collegeboard.org. AP Central is the official online home for the AP Program: apcentral.collegeboard.org. AP® Environmental Science 2022 Free-Response Questions ENVIRONMENTAL SCIENCE SECTION II Time—1 hour and 10 minutes 3 Questions Directions: Answer all three questions, which are weighted equally; the suggested time is about 22 minutes for answering each question. Write all your answers in the Free Response booklet. Where calculations are required, clearly show how you arrived at your answer. Where explanation or discussion is required, support your answers with relevant information and/or specific examples. You may plan your answers in this orange booklet, but no credit will be given for anything written in this booklet. You will only earn credit for what you write in the separate Free Response booklet. 1. Common snapping turtles, Chelydra serpentina, are primarily aquatic, but they lay their eggs on land. Researchers are interested in understanding the impact of pollution on turtle nesting sites. The researchers examined nesting sites at two agricultural areas along the floodplain of a river upstream and downstream from a chemical factory that is a known source of aqueous mercury pollution. Turtle eggs, soil, and vegetation samples taken from areas around turtle nests downstream from the chemical factory showed high levels of mercury in a previous study. Mercury was not detected in samples taken upstream from the chemical factory. © 2022 College Board. Visit College Board on the web: collegeboard.org. 2 GO ON TO THE NEXT PAGE. AP® Environmental Science 2022 Free-Response Questions (a) The map shows locations of both successful and unsuccessful turtle nests. (i) Identify the area with the greatest nest success rate, based on the information in the diagram. (ii) Identify the dependent variable in the study. (iii) Based on the information provided, identify a likely scientific question for the study. (iv) Describe why researchers measured mercury levels in locations upstream from the factory. (v) There are plans to remove trees and other vegetation along the river bank. Explain how this modification could affect the location and number of successful turtle nests in Area B. (b) Mercury can affect organisms and ecosystems in many ways. (i) Describe how a persistent pollutant, such as mercury, can negatively affect an organism. (ii) Describe how a persistent pollutant, such as mercury, can negatively affect an ecosystem. (iii) Researchers measured methylmercury in a location downstream from the factory. Explain how methylmercury could be present in the stream. (iv) Researchers claimed that the soil nearest to the river has higher levels of mercury than the field has, and those elevated levels have affected the nesting success for turtles. Explain how the pattern shown in the diagram supports or refutes this claim. (c) The turtle study was conducted in an agricultural area. Describe how a specific agricultural practice changes the soil in an area. __________________________________________________________ Begin your response to this question at the top of a new page in the separate Free Response booklet and fill in the appropriate circle at the top of each page to indicate the question number. © 2022 College Board. Visit College Board on the web: collegeboard.org. 3 GO ON TO THE NEXT PAGE. AP® Environmental Science 2022 Free-Response Questions 2. Developments in advanced hydraulic fracturing (fracking) technologies have allowed the total oil and gas production in the United States to increase rapidly. (a) The graph shows the methane concentration in drinking water from home wells and the distance to the nearest fracking well in Pennsylvania. (i) Based on the data in the graph, identify the highest methane concentration found in well water in Pennsylvania. (ii) Based on the data in the graph, describe the relationship between the concentration of methane in well water and the distance to a fracking well. (iii) Based on the data in the graph, identify the minimum safe distance that a new water well should be located from an existing fracking well. (iv) Explain how fracking fluid is used to access oil and natural gas in sedimentary rock, such as shale, during the fracking process. (v) Identify one negative geologic effect in an area where hydraulic fracturing (fracking) occurs. (b) The volume of water used for oil and gas extraction is 28 times greater than it was fifteen years ago. Much of the water used for oil and gas extraction comes from groundwater sources in arid or semiarid regions. This increased use of water for fracking may mean that less water is available for local use. (i) The use of groundwater for fracking is an example of individuals using a shared resource for their own self-interest. Identify the environmental concept illustrated by this example of overuse of a shared resource. (ii) Describe one environmental problem that may result from increased use of groundwater for fracking in arid or semiarid regions. (iii) Describe how overuse of coastal groundwater supplies can result in water that is unsuitable for human consumption. © 2022 College Board. Visit College Board on the web: collegeboard.org. 4 GO ON TO THE NEXT PAGE. AP® Environmental Science 2022 Free-Response Questions (c) In addition to water quality issues caused by fossil fuel extraction, air quality can also be negatively affected by combustion of oil and natural gas. (i) Make a claim for a realistic governmental action to improve air quality by reducing consumption of oil. (ii) Justify the action proposed in part (c)(i) by stating a potential environmental advantage of that action, other than slowing global climate change. __________________________________________________________ Begin your response to this question at the top of a new page in the separate Free Response booklet and fill in the appropriate circle at the top of each page to indicate the question number. © 2022 College Board. Visit College Board on the web: collegeboard.org. 5 GO ON TO THE NEXT PAGE. AP® Environmental Science 2022 Free-Response Questions 3. Increasing global urbanization causes associated problems such as the formation of urban heat islands. (a) Describe how urbanization leads to the formation of urban heat islands. (b) Urban heat islands have been linked to a variety of environmental problems. (i) Propose a reasonable solution that could help lower the temperature increases caused by urban heat islands. (ii) Justify the solution proposed in part (b)(i) by providing one additional benefit other than reducing temperatures in urban heat islands. (c) Urban areas are increasingly using solar energy to generate electricity for residences and businesses. (i) As a result of improved technology, the efficiency of solar panels has changed over time. In 1992 a solar cell had a maximum efficiency of 15.9%. In 2017 a solar cell prototype capable of 44.5% efficiency was produced. Calculate the percent change in efficiency from the 1992 cell to the 2017 cell. Show your work. (ii) The average home in the United States uses 12,900 kWh of electricity per year. The local power company is raising the cost of purchasing electricity from $0.11 per kWh to $0.13 per kWh. Assuming a home uses the average kWh of electricity in one year, calculate the change in electricity cost for one year for the homeowner. Show your work. (iii) The roof of a typical house in the United States receives a total of four hours of sunlight per day that can be converted by solar panels into electricity. A house has 30 solar panels on its roof, and each panel generates a maximum output of 300 watts. Calculate how many kWh can be produced by the system at maximum output in one calendar year. Show your work. (d) Explain why the Northern Hemisphere receives more solar energy from the Sun between June and August than the Southern Hemisphere receives between June and August. __________________________________________________________ Begin your response to this question at the top of a new page in the separate Free Response booklet and fill in the appropriate circle at the top of each page to indicate the question number. © 2022 College Board. Visit College Board on the web: collegeboard.org. 6 GO ON TO THE NEXT PAGE. AP® Environmental Science 2022 Free-Response Questions STOP END OF EXAM © 2022 College Board. Visit College Board on the web: collegeboard.org. 7 2022 AP Environmental Science ® Free-Response Questions Set 2 © 2022 College Board. College Board, Advanced Placement, AP, AP Central, and the acorn logo are registered trademarks of College Board. Visit College Board on the web: collegeboard.org. AP Central is the official online home for the AP Program: apcentral.collegeboard.org. AP® Environmental Science 2022 Free-Response Questions ENVIRONMENTAL SCIENCE SECTION II Time—1 hour and 10 minutes 3 Questions Directions: Answer all three questions, which are weighted equally; the suggested time is about 22 minutes for answering each question. Write all your answers in the Free Response booklet. Where calculations are required, clearly show how you arrived at your answer. Where explanation or discussion is required, support your answers with relevant information and/or specific examples. You may plan your answers in this orange booklet, but no credit will be given for anything written in this booklet. You will only earn credit for what you write in the separate Free Response booklet. 1. The dead zone in the Gulf of Mexico occurs every summer when winter snow melts and spring rain flows into the Mississippi River. Recent studies have shown that both the total area covered by algae and the depth of the algal mass in the dead zone are increasing. (a) Various land use practices can have different effects on the waters that surround a dead zone. (i) Identify the land use that covers the least amount of area in the Mississippi River watershed, based on the diagram. (ii) Describe one way that the land use practice at location X in the diagram could contribute to the dead zone in the Gulf of Mexico. (iii) Describe one way that urban areas in the Mississippi River watershed could contribute to the dead zone in the Gulf of Mexico. © 2022 College Board. Visit College Board on the web: collegeboard.org. 2 GO ON TO THE NEXT PAGE. AP® Environmental Science 2022 Free-Response Questions (b) The dead zone in the Gulf of Mexico has both economic and environmental effects for coastal communities. (i) Describe how a dead zone affects marine organisms living in the Gulf of Mexico. (ii) Describe one economic effect on communities along the Gulf of Mexico that can result from the presence of the dead zone. (iii) Describe one factor that causes the area of the dead zone in the Gulf of Mexico to increase in the summer months. (c) Researchers want to examine the effect of riparian vegetation buffers on water quality in streams in agricultural areas. Researchers will measure the water nutrient concentrations over the course of one year. The study sites are located 100 meters downstream from areas either with or without riparian vegetation buffers. (i) Identify a testable hypothesis for the study. (ii) Describe a control that the researchers could use in the study. (iii) Identify one water quality test, other than measuring nitrates or phosphates, that the researchers could use to evaluate how riparian vegetation buffers affect water quality. (iv) During the investigation, researchers discovered that some of the land next to one of the streams with a riparian vegetation buffer is going to be converted from cornfields into a large-scale concentrated animal feeding operation. Explain one way that this change in land use could alter the results of the study. __________________________________________________________ Begin your response to this question at the top of a new page in the separate Free Response booklet and fill in the appropriate circle at the top of each page to indicate the question number. © 2022 College Board. Visit College Board on the web: collegeboard.org. 3 GO ON TO THE NEXT PAGE. AP® Environmental Science 2022 Free-Response Questions 2. Biologists collected data on the abundance of lizards on several Pacific islands with and without mongoose populations. The surveys were conducted at different locations on the islands by counting the number of lizards observed per hour and included habitats with both undisturbed areas and anthropogenically disturbed areas. (a) The graph shows data collected by biologists on lizard numbers on several Pacific islands. (i) Based on the data in the graph, identify the habitat type with the greatest number of lizards. (ii) Based on the data in the graph, describe the relationship between the lizard numbers observed on islands with and without mongoose populations. Globally, islands vary in size, location, and habitat. (b) Based on the theory of island biogeography, describe the characteristics of an island with the greatest species diversity. (c) Island ecosystems are often threatened by invasive species, such as the mongoose populations studied in the survey. (i) Describe one environmental problem caused by invasive animal species. (ii) Invasive species are often pests. Make a claim that proposes one way to control pest species. (iii) Justify the solution proposed in (c)(ii) by providing an additional benefit of the solution. (d) Islands provide humans with many ecosystem services. However, humans may alter ecosystems when they obtain these services. Large-scale commercial sugarcane farming on the Pacific islands has led to significant ecological damage. (i) Identify a provisioning ecosystem service provided by primary forests. (ii) Based on the data in the graph, explain how replacing primary forests with sugarcane fields may have affected the number of lizards counted on the mongoose-free Pacific islands. (iii) The long-term use of monocultures in commercial sugarcane farming is one cause of the ecological damage. Describe one problem associated with monocultures. One solution to the ecological damage of monocultures is to use a form of crop rotation using legumes. (e) Describe an advantage of crop rotation using legumes on soil fertility. © 2022 College Board. Visit College Board on the web: collegeboard.org. 4 GO ON TO THE NEXT PAGE. AP® Environmental Science 2022 Free-Response Questions 3. North Carolina is one of the fastest-growing states by population in the United States, with most growth concentrated in major cities like Charlotte. Increased population leads to increased demands for resources such as power and water. The majority of electrical energy in North Carolina is produced during the combustion of coal. (a) Identify one negative human health effect linked to the exposure to pollutants resulting from the combustion of coal. (b) Coal ash, the powdery, solid substance that remains after coal combustion, presents a variety of potential environmental issues. Disposal of toxic coal ash is a growing concern in the state. Coal ash can be mixed with water and disposed of in large, unlined pits or as dry ash in landfills. (i) Describe an environmental problem associated with coal ash waste disposal. (ii) A proposed solution is to dispose of North Carolina’s coal ash in clay-lined pits. Justify this solution by providing one advantage of using clay soil. (c) The population of Charlotte, North Carolina, has grown over the last few decades. The table shows the increase in the population size of Charlotte from 2013 to 2019. Population of Charlotte, North Carolina, 2013–2019 Year Population 2013 757,278 2014 774,807 2015 792,137 2016 808,834 2017 826,060 2018 841,611 2019 857,425 (i) Calculate the percent change in Charlotte’s population from 2013 to 2019. Show your work. (ii) Based on Charlotte’s 2019 growth rate of 1.88%, calculate the year when the population of Charlotte will double, assuming the growth rate stays the same. Show your work. (iii) The average Charlotte resident uses 90 gallons of water per day. Calculate the gallons of water used by the population of Charlotte in the year 2018. Show your work. (d) Drought periods are becoming more frequent in North Carolina, causing water resources to become more scarce. Describe one realistic action that citizens could take to reduce domestic outdoor water use. __________________________________________________________ Begin your response to this question at the top of a new page in the separate Free Response booklet and fill in the appropriate circle at the top of each page to indicate the question number. © 2022 College Board. Visit College Board on the web: collegeboard.org. 5 GO ON TO THE NEXT PAGE. AP® Environmental Science 2022 Free-Response Questions STOP END OF EXAM © 2022 College Board. Visit College Board on the web: collegeboard.org. 6 2021 AP Environmental Science ® Free-Response Questions Set 1 © 2021 College Board. College Board, Advanced Placement, AP, AP Central, and the acorn logo are registered trademarks of College Board. Visit College Board on the web: collegeboard.org. AP Central is the official online home for the AP Program: apcentral.collegeboard.org. AP® Environmental Science 2021 Free-Response Questions ENVIRONMENTAL SCIENCE SECTION II Time—1 hour and 10 minutes 3 Questions Directions: Answer all three questions, which are weighted equally; the suggested time is about 22 minutes for answering each question. Write all your answers in the Free Response booklet. Where calculations are required, clearly show how you arrived at your answer. Where explanation or discussion is required, support your answers with relevant information and/or specific examples. You may plan your answers in this orange booklet, but no credit will be given for anything written in this booklet. You will only earn credit for what you write in the separate Free Response booklet. 1. A homeowner in the Northern Hemisphere is considering installing photovoltaic (PV) panels on the roof of the home to help provide electricity for the home. The homeowner has read conflicting reports on which compass direction the panels should face to maximize the amount of electricity (in kWh ) that the panels can produce. (a) The homeowner plans to design an experiment to determine the direction of the panels for maximal electricity production. (i) Identify the independent variable in the experiment. (ii) Identify the dependent variable in the experiment. (iii) Identify a reasonable hypothesis for the experiment. (iv) Describe one variable that was not discussed that could affect the results of the study. © 2021 College Board. Visit College Board on the web: collegeboard.org. 2 GO ON TO THE NEXT PAGE. AP® Environmental Science 2021 Free-Response Questions (b) The diagram below shows another way of generating electricity using a renewable resource. The arrows indicate the flow of water. (i) Identify the location shown in the diagram where the kinetic energy of the water is transformed into mechanical energy. (ii) Explain why the water in the storage reservoir has potential energy that is useful in hydroelectric power generation. (iii) Explain how coupling hydroelectric power with solar or wind power is an advantage to providing a constant source of electricity to a community. (iv) Explain how a hydroelectric power system, like the one depicted, may be negatively affected by climate change. (c) Over time, reservoirs that form behind dams can undergo changes. (i) Identify one advantage, other than the generation of hydroelectric power, of the formation of a reservoir behind a hydroelectric dam. (ii) Explain the effect of increased silt in the reservoir on the hydroelectric power system. __________________________________________________________ Begin your response to this question at the top of a new page in the separate Free Response booklet and fill in the appropriate circle at the top of each page to indicate the question number. © 2021 College Board. Visit College Board on the web: collegeboard.org. 3 GO ON TO THE NEXT PAGE. AP® Environmental Science 2021 Free-Response Questions 2. Pesticides have been utilized for many years to increase food production and control pest populations. Pesticide use can be both beneficial and harmful to humans and other organisms. (a) Pesticide use has advantages, disadvantages, and unintended consequences on human health. Describe one benefit to human health that can result from the use of pesticides. (b) Identify one way chemical pesticides can enter the human body. Cotton farmers in the southern United States used a chemical pesticide to control an insect cotton-crop pest over a 40-year period. To study the effectiveness of the pesticide as an insect pest-control strategy, traps were placed in treated cotton fields and the number of pests captured were compared to application rates for the pesticide. The results of the study are shown in the table below. Year Grams of Pesticide Number of Crop Insect Applied per Hectare Pests Captured 1960 0 700 1975 500 2 1980 500 3 1985 500 8 1990 550 14 1995 600 83 2000 700 150 2005 800 405 2010 900 727 2015 1,000 1,100 (c) Use the data in the table to answer the following questions. (i) Identify the year when the pesticide was most effective at reducing the size of the pest population. (ii) Describe the change in the number of crop insect pests in the cotton fields over time. (iii) Explain how the change in the cotton-crop pesticide effectiveness between the initial application in 1975 and the latest application in 2015 illustrates genetic resistance in pests, based on the data in the table. (d) Describe TWO effects of pesticide use, other than death, on nontarget wildlife. © 2021 College Board. Visit College Board on the web: collegeboard.org. 4 GO ON TO THE NEXT PAGE. AP® Environmental Science 2021 Free-Response Questions (e) There are many problems associated with the repeated application of chemical pesticides to reduce pest populations. (i) Crop rotation is often used to reduce pesticide use. Describe the process of crop rotation. (ii) Propose one reasonable method, other than crop rotation, of reducing the use of pesticides in agricultural practices while still maintaining a high crop yield. (iii) Justify how the method proposed in (e)(ii) would provide a benefit to humans. __________________________________________________________ Begin your response to this question at the top of a new page in the separate Free Response booklet and fill in the appropriate circle at the top of each page to indicate the question number. © 2021 College Board. Visit College Board on the web: collegeboard.org. 5 GO ON TO THE NEXT PAGE. AP® Environmental Science 2021 Free-Response Questions 3. Habitat destruction and fragmentation can have many different effects on species. (a) Describe a characteristic of a specialist species that would make the specialist species more likely to be negatively affected by habitat fragmentation than a generalist species. A rapidly growing suburban municipality purchases nearby forested land and proposes a newly planned housing development, which would involve clear-cutting much of the area for the construction of single-family homes. While evaluating the land, the development committee discovers that development will encroach upon the habitat of a wood thrush population. The wood thrush is a solitary, territorial bird whose preferred habitat consists of large, intact densely forested areas. Wood thrush populations are also threatened by cowbirds. A cowbird lays her egg in an existing nest of a wood thrush. After the cowbird egg hatches, the cowbird pushes the unhatched wood thrush eggs out. The wood thrush parents raise the cowbird hatchling as their own. (b) Identify the symbiotic relationship between the wood thrush and the cowbird. (c) Describe one ecological advantage of leaving areas of undeveloped forest in the development plan as compared to clear-cutting the property. (d) Propose a solution that will minimize the effect of development on the resident population of wood thrush while still meeting the municipality’s need for a housing development. (e) A male wood thrush needs a minimum of 800 m2 of territory for reproduction. The municipal development committee has set a biodiversity preservation target of 275 male wood thrush territories. Calculate the area that must be set aside to support the goal of 275 male thrush territories. Show your work. (f) A real estate developer wants to build houses on the property. The plan will support 1,000 lots with a lot size of 1,100 m2. The developer has proposed setting aside land equal to 10% of the size of each lot it sells. Calculate the maximum number of male wood thrush territories that could be created under this proposal. Show your work. (g) Calculate the percentage of each of the 1,000 lots that would need to be set aside in order to support the goal of 275 male wood thrush territories. Show your work. __________________________________________________________ Begin your response to this question at the top of a new page in the separate Free Response booklet and fill in the appropriate circle at the top of each page to indicate the question number. © 2021 College Board. Visit College Board on the web: collegeboard.org. 6 GO ON TO THE NEXT PAGE. AP® Environmental Science 2021 Free-Response Questions STOP END OF EXAM © 2021 College Board. Visit College Board on the web: collegeboard.org. 7 2021 AP Environmental Science ® Free-Response Questions Set 2 © 2021 College Board. College Board, Advanced Placement, AP, AP Central, and the acorn logo are registered trademarks of College Board. Visit College Board on the web: collegeboard.org. AP Central is the official online home for the AP Program: apcentral.collegeboard.org. AP® Environmental Science 2021 Free-Response Questions ENVIRONMENTAL SCIENCE SECTION II Time—1 hour and 10 minutes 3 Questions Directions: Answer all three questions, which are weighted equally; the suggested time is about 22 minutes for answering each question. Write all your answers in the Free Response booklet. Where calculations are required, clearly show how you arrived at your answer. Where explanation or discussion is required, support your answers with relevant information and/or specific examples. You may plan your answers in this orange booklet, but no credit will be given for anything written in this booklet. You will only earn credit for what you write in the separate Free Response booklet. 1. Soil erosion is one of the most serious soil-degrading processes. Each year tons of soil erode from cropland, pastures, forests, and other places. The amount of erosion varies dramatically among various land-use types. The figure above shows the effects of different agricultural practices and slopes on annual erosion rates. (a) Refer to the graph above for the following. (i) Identify the scientific question that resulted in the data presented in the graph. (ii) Identify the agricultural practice that could be used on a 15% slope without leading to a higher than tolerable loss of soil. (iii) Describe the effect of adding a cover crop compared to using the no-till method. (iv) Identify one natural mechanism of soil erosion. © 2021 College Board. Visit College Board on the web: collegeboard.org. 2 GO ON TO THE NEXT PAGE. AP® Environmental Science 2021 Free-Response Questions (b) Sediment from erosion can enter streams and affect water quality. One way sediment can enter a stream is from nearby road construction. Two methods to reduce sediment run-off in streams are to either put down straw bales or plant grass. The hypothesis to be tested is that straw bales reduce more sediment run-off than planted grass does. To test the hypothesis, two plots near a road under construction are measured. On one plot (A), straw bales are used to cover the soil, while a second plot (B) is planted with grass. The sediment discharge from each plot is measured after rainfall. (i) Identify the dependent variable stated in the hypothesis. (ii) Describe one way to add a control to improve the design of the study. (iii) Identify one variable that was not discussed that could affect the results of the study. Sediments reaching streams affect water clarity, which is tested by determining turbidity. Turbidity can be determined by measuring the depth at which a submerged object can no longer be seen from the surface. Sample Group Turbidity Straw bale plots (plot A) 12 cm Planted grass plots (plot B) 28 cm (iv) Based on the data in the table above, make a claim about the stated hypothesis. (c) Several fish species lay their eggs in the gravel in the streams under investigation in the study. (i) Describe the type of survivorship curve expected for these fish species. (ii) Explain why the input of sediment to a stream can negatively affect reproduction of fish that lay their eggs in the gravel of the streambed. __________________________________________________________ Begin your response to this question at the top of a new page in the separate Free Response booklet and fill in the appropriate circle at the top of each page to indicate the question number. © 2021 College Board. Visit College Board on the web: collegeboard.org. 3 GO ON TO THE NEXT PAGE. AP® Environmental Science 2021 Free-Response Questions 2. Biodiversity around the world is changing as a result of anthropogenic influences. (a) The map represents species richness of amphibians around the globe. Use the map to answer the following questions. (i) Identify the latitudinal range with the greatest amphibian species richness. (ii) Identify what biome this range most likely represents. (iii) Describe one reason amphibian species richness would tend to be highest in this region. (b) There are many environmental threats facing amphibians today, such as deforestation. Describe one possible anthropogenic reason for deforestation. (c) Many factors influence biodiversity. (i) Explain how the species richness of an ecosystem influences its response to environmental stressors. (ii) Explain why amphibian biodiversity is declining globally, other than from deforestation. (d) Currently, wildlife species are going extinct at an alarming rate. To combat this threat, governments around the world have enacted legislation and signed treaties to protect species threatened by extinction. © 2021 College Board. Visit College Board on the web: collegeboard.org. 4 GO ON TO THE NEXT PAGE. AP® Environmental Science 2021 Free-Response Questions (i) Identify one specific piece of legislation that has been designed to protect species threatened by extinction. (ii) Explain how the requirements of the legislation identified in part (d)(i) specifically protect species threatened by extinction. (e) A town is considering selling an undeveloped parcel of land along its border for residential developments. The square parcel of land consists of approximately 30% wetland and 70% pasture. The wetland runs through the middle of the property for its entire width and is home to three native frog species. (i) Propose a viable solution that will result in the protection of the native frog species while still allowing for maximum profit of the property development. (ii) Justify the solution proposed in (e)(i) by describing a potential advantage of the plan, other than frog protection. __________________________________________________________ Begin your response to this question at the top of a new page in the separate Free Response booklet and fill in the appropriate circle at the top of each page to indicate the question number. © 2021 College Board. Visit College Board on the web: collegeboard.org. 5 GO ON TO THE NEXT PAGE. AP® Environmental Science 2021 Free-Response Questions 3. Approximately 350 coal-fired power plants in the United States are older than the 30 -year anticipated life-span for a coal generator. One problem with these aging power plants is that many lack the necessary modern air pollution controls. Additionally, there are concerns about rising fuel costs, so many utility companies are planning to retire coal-fired plants and build new natural-gas power plants. (a) Describe why coal is considered a nonrenewable energy source. (b) Describe one potential environmental advantage of replacing a coal-fired power plant with a natural-gas power plant. (c) Describe one economic advantage of using natural gas, rather than coal, in producing electricity. (d) When natural gas is used to heat homes, it can produce carbon monoxide gas, which can lead to carbon monoxide poisoning in humans. Propose a solution to reduce the incidence of carbon monoxide poisoning in humans. Particulate matter is another common pollutant in emissions from vehicles, coal-fired power plants, and various other sources. One size of particulates, PM2.5 , presents a particular risk to human health. ATMOSPHERIC CONCENTRATION OF PARTICULATE MATTER IN 1990 AND 2016 Year Average Annual Atmospheric Concentration of PM2.5 (μg/m3) 1990 85 2016 188 (e) Calculate the percent change in the average annual PM2.5 concentration in the air from 1990 to 2016. Show your work. (f) Trees can remove PM2.5 from the atmosphere when particulates settle on the leaves and are subsequently washed onto soil by rain. The average annual removal of PM2.5 is 2.3 kilograms per hectare. Calculate the decrease in PM2.5 removal in kilograms if logging reduced a forested area from 50,000 hectares to 43,000 hectares. Show your work. (g) Research has shown that hospital admissions for cardiovascular problems increase 1% with every 10% increase in PM2.5 concentration. A city experienced a 23% increase in PM2.5 concentration and had 7,390 hospital admissions for cardiovascular issues over a one-year period. Calculate the anticipated increase in the number of hospital admissions for cardiovascular issues during the next year if the PM2.5 concentration continues to rise at an identical rate. Show your work. __________________________________________________________ Begin your response to this question at the top of a new page in the separate Free Response booklet and fill in the appropriate circle at the top of each page to indicate the question number. © 2021 College Board. Visit College Board on the web: collegeboard.org. 6 GO ON TO THE NEXT PAGE. AP® Environmental Science 2021 Free-Response Questions STOP END OF EXAM © 2021 College Board. Visit College Board on the web: collegeboard.org. 7 2019 AP Environmental Science ® Free-Response Questions © 2019 The College Board. College Board, Advanced Placement, AP, AP Central, and the acorn logo are registered trademarks of the College Board. Visit the College Board on the web: collegeboard.org. AP Central is the official online home for the AP Program: apcentral.collegeboard.org. 2019 AP® ENVIRONMENTAL SCIENCE FREE-RESPONSE QUESTIONS ENVIRONMENTAL SCIENCE SECTION II Time—1 hour and 30 minutes 4 Questions Directions: Answer all four questions, which are weighted equally; the suggested time is about 22 minutes for answering each question. Write all your answers on the pages following the questions in this book. Where calculations are required, clearly show how you arrived at your answer. Where explanation or discussion is required, support your answers with relevant information and/or specific examples. 1. The piping plover is a globally threatened species, with perhaps as few as 2,000 nesting pairs remaining in the Atlantic population of these migratory shorebirds. Plovers were nearly hunted to extinction in the nineteenth century. Plovers prefer to nest and search for food on open sandy beaches between sparsely vegetated sand dunes. Washovers, where sand is washed up from the beach and buries vegetated areas during big storms, are also important to plovers because they provide moist and undisturbed habitat for plover adults and their chicks. Ecologists with the Elliott Oceanographic Institute mapped the distribution of plover nests during two seasonal surveys of nesting sites over a ten-year period on Assateague Island. This is a barrier island, a long, narrow island running parallel to the Atlantic coast of Virginia. © 2019 The College Board. Visit the College Board on the web: collegeboard.org. -2- GO ON TO THE NEXT PAGE. 2019 AP® ENVIRONMENTAL SCIENCE FREE-RESPONSE QUESTIONS (a) Use the maps provided to answer the following questions. (i) Identify the preferred nesting habitat for piping plovers. (ii) Describe the change in the number of piping plover nests on Assateague Island between 1999 and 2009. (iii) Describe one likely reason for the change in the number of piping plover nests between 1999 and 2009. (b) Coastal species are affected by more than just natural events. (i) Special beach restrictions can help piping plovers during nesting season. Describe one restriction that could reasonably be implemented to help prevent the destruction of plover nests by human actions. (ii) In addition to providing habitat for piping plovers, barrier islands (and closely related landforms) are important for other reasons. Explain one way that these features help to preserve and protect the environment in coastal regions. (iii) Identify one human action that directly threatens coastal habitats and describe one impact on species, other than the piping plover, that use the habitat. Approximately 40% of the United States population resides in coastal areas, such as areas near Assateague Island, where sea level rise and shoreline erosion is occurring. (c) Identify one economic impact on coastal communities that has resulted from rising sea levels. (d) Describe TWO methods that may be used locally to protect coastal communities from rising sea levels. © 2019 The College Board. Visit the College Board on the web: collegeboard.org. -3- GO ON TO THE NEXT PAGE. 2019 AP® ENVIRONMENTAL SCIENCE FREE-RESPONSE QUESTIONS 2. As conventional sources of crude oil are depleted, unconventional sources such as oil sands (also known as tar sands) are being utilized. Oils sands contain bitumen, which can be processed into a synthetic crude oil. A region of boreal forest in Alberta, Canada, that covers a deposit of oil sands will be cut and removed during the process of bitumen extraction. It is estimated that the deposit contains 73 billion barrels of recoverable bitumen. The rate of extraction from the deposit will be approximately 1 million barrels of bitumen per day. (a) Identify one ecological benefit, other than providing habitat, that is provided by forests. (b) Identify one economic benefit that is provided by forests. (c) Describe TWO environmental consequences, other than those related to the loss of boreal forest habitat, that result from the extraction of bitumen or the transportation of synthetic oil to customers. (d) Assuming the above extraction rate, calculate how many days will be needed to extract the recoverable volume of bitumen from the oil sands. (e) Calculate how many years will be needed to fully extract the recoverable volume of bitumen from the oil sands. (f) Monthly production of synthetic crude oil is 30 million barrels. Producing one barrel of synthetic crude oil uses two barrels of heated freshwater. Calculate the number of barrels of freshwater needed each year to supply this demand. © 2019 The College Board. Visit the College Board on the web: collegeboard.org. -4- GO ON TO THE NEXT PAGE. 2019 AP® ENVIRONMENTAL SCIENCE FREE-RESPONSE QUESTIONS 3. The graph shows measurements of atmospheric levels of carbon dioxide (CO2 ) at Mauna Loa Observatory, Hawaii, and the measurements of pH levels in the ocean nearby at Station ALOHA. Measurements of pH began in 1992. (a) Use the graph above to answer the following questions. (i) Determine the concentration of CO 2 (in ppm) recorded at Mauna Loa in 2005. (ii) Determine the pH recorded at Station ALOHA in 2005. (b) Changes in atmospheric carbon dioxide affect Earth’s oceans. (i) Predict the effect of increased concentration of atmospheric CO 2 on the concentration of CO 2 in the ocean. (ii) Based on the data, identify the relationship between the concentration of atmospheric CO 2 and the pH of ocean water. (iii) Provide the complete chemical equation that represents the reaction between oceanic carbon dioxide (CO2 ) and water ( H 2 O ). (iv) Identify the specific environmental problem that directly results from the decrease in pH of Earth’s oceans. (c) Changes in pH in the world’s oceans pose a risk to many marine organisms. (i) Explain why certain organisms, in particular those with calcium carbonate shells or exoskeletons, are threatened by the decreasing pH levels measured in seawater. (ii) Other than threats posed by decreasing pH, identify an additional anthropogenic threat to the world’s coral reef ecosystems and describe how the threat damages the coral reefs and coral reef ecosystems. © 2019 The College Board. Visit the College Board on the web: collegeboard.org. -5- GO ON TO THE NEXT PAGE. 2019 AP® ENVIRONMENTAL SCIENCE FREE-RESPONSE QUESTIONS 4. One reason that people visit national parks is to view the scenery. Visibility at the four parks in the graph has been reduced over time so that by 2015 the visibility was an average of 70 miles less than the historical visibility. Regional air pollutant sources are commonly located over 100 miles away from national parks. (a) Based on the data provided in the graph, identify the national park that had the greatest loss of visibility as of 2015 when compared with the historical natural visibility. (b) Visibility in national parks can be affected by many different air pollutants. (i) Identify a primary air pollutant. (ii) Describe how a primary air pollutant becomes part of the atmosphere. (iii) Identify a secondary air pollutant. (iv) Describe how a secondary air pollutant is formed within the atmosphere. (c) In 1990 Great Smoky Mountains National Park had a visibility of 25 miles. Visibility data for 2015 can be determined from the graph above. (i) Calculate the percentage increase in visibility from 1990 to 2015. (ii) Discuss TWO specific actions that the state or federal government could take or encourage to further improve the visibility in Great Smoky Mountains National Park. (d) Excluding air pollution, discuss TWO additional ways national park ecosystems are being degraded by high levels of visitor use. STOP END OF EXAM © 2019 The College Board. Visit the College Board on the web: collegeboard.org. -6- 2018 AP Environmental Science Free-Response Questions © 2018 The College Board. College Board, Advanced Placement Program, AP, AP Central, and the acorn logo are registered trademarks of the College Board. Visit the College Board on the Web: www.collegeboard.org. AP Central is the official online home for the AP Program: apcentral.collegeboard.org. 2018 AP® ENVIRONMENTAL SCIENCE FREE-RESPONSE QUESTIONS ENVIRONMENTAL SCIENCE SECTION II Time—1 hour and 30 minutes 4 Questions Directions: Answer all four questions, which are weighted equally; the suggested time is about 22 minutes for answering each question. Write all your answers on the pages following the questions in this book. Where calculations are required, clearly show how you arrived at your answer. Where explanation or discussion is required, support your answers with relevant information and/or specific examples. 1. Read the following article from the Fremont Daily Times and answer the questions that follow. (a) The students want to reduce the school’s carbon footprint. (i) Define carbon footprint. (ii) Identify one way the school’s heating system is likely adding to the school’s carbon footprint. (iii) Describe one realistic way to reduce the contribution of the heating system to the school’s carbon footprint. (b) Identify TWO environmental benefits of a living green roof, such as that suggested by Councilperson Fassler. (c) Describe TWO practices the cafeteria’s food service could use to decrease the environmental impacts of Fremont High School. (d) Discuss TWO benefits of using native plants for landscaping at Fremont High School. (e) During the renovation, the carpeting must be replaced. Discuss one environmental benefit of using flooring made of plant material, such as cork or bamboo, instead of carpet made of synthetic fibers. © 2018 The College Board. Visit the College Board on the Web: www.collegeboard.org. -2- GO ON TO THE NEXT PAGE. 2018 AP® ENVIRONMENTAL SCIENCE FREE-RESPONSE QUESTIONS 2. An offshore wind farm project using turbines to generate electricity is to be built along the Atlantic coast of the United States. It will be located about 13 km from the coast in water with an average depth of 10 m. (a) Describe one environmental benefit associated with an offshore wind project. (b) Identify and describe one potential economic effect of an offshore wind project. (c) Describe one additional way, other than wind power, that oceans can provide renewable energy for the generation of electricity. The project will consist of 200 wind turbines, each with a capacity of 4 megawatts (MW). Each turbine costs $1.2 million to build. Electrical demand in the area to be served by the project is expected to be 2.0 × 106 MWh per year. (d) Calculate how much electricity (in MWh) the wind project needs to generate per year in order to provide 80% of the annual electrical demand in the service area. Show all work. (e) Customers in the service area pay $0.20/kWh for electricity. Calculate how much revenue will be produced if the wind turbines provide 80% of the annual electrical demand in the service area. Show all work. (f) Assuming all turbines are operating, calculate how many hours the wind turbines must operate to provide 80% of the annual electrical demand in the service area. Show all work. © 2018 The College Board. Visit the College Board on the Web: www.collegeboard.org. -3- GO ON TO THE NEXT PAGE. 2018 AP® ENVIRONMENTAL SCIENCE FREE-RESPONSE QUESTIONS 3. An Arctic food web includes the following organisms. (a) Refer to the food web above to complete the following table. Organism from Arctic food web (i) Identify a primary producer (ii) Identify a primary consumer (iii) Identify a secondary consumer (b) Other than showing which organisms are consumed by other organisms, describe what is indicated by the direction of the arrows in the diagram. © 2018 The College Board. Visit the College Board on the Web: www.collegeboard.org. -4- GO ON TO THE NEXT PAGE. 2018 AP® ENVIRONMENTAL SCIENCE FREE-RESPONSE QUESTIONS As the amount of sea ice has decreased, larger expanses of the Arctic Ocean are now completely free of sea ice for several weeks each summer. Ringed seals, the preferred prey of polar bears, come to holes in the sea ice to breathe. (c) Describe how the change in sea ice habitat is affecting polar bears’ ability to hunt and feed. (d) Explain how melting sea ice leads to a feedback loop that increases Arctic warming. (e) Many species, including some whales and birds, will travel thousands of kilometers during annual migrations. (i) Provide one reason a species may migrate a long distance. (ii) The North Atlantic right whale migrates between subtropical and polar waters annually. Nearly 50 percent of right whale deaths are due to human activities. Describe one commercial activity, other than whaling, that may result in the death of right whales. (iii) Describe one strategy that could reasonably be implemented to decrease right whale deaths caused by the commercial activity you described in part (ii). © 2018 The College Board. Visit the College Board on the Web: www.collegeboard.org. -5- GO ON TO THE NEXT PAGE. 2018 AP® ENVIRONMENTAL SCIENCE FREE-RESPONSE QUESTIONS 4. In many parts of the world, biomass like peat, wood, and animal waste is burned indoors for cooking and home heating. Combustion of these fuels releases harmful household air pollutants that pose a health threat to billions of people, mostly in less developed countries. (a) Air pollutants are released during the burning of biomass indoors for cooking and heating. (i) Identify TWO air pollutants released during the burning of biomass indoors for cooking and heating. (ii) Identify a specific human respiratory illness that one of the pollutants you identified may cause. (b) Identify one realistic approach, other than banning the practice of burning biomass indoors, that could be used to reduce the impact of biomass combustion indoors on human respiratory health. Describe how this approach could reduce the incidence of respiratory illness. In 2016 approximately four million people died from illnesses attributed to household air pollutants from burning biomass indoors. More than 10 percent of these deaths occurred in children under the age of five in less developed countries. (c) Discuss one reason children under the age of five are at a greater risk than adults for illnesses linked to household air pollutants. In more developed countries, indoor air pollution is also a problem. Common indoor air pollutants in developed countries include: • asbestos • radon • mold (d) Choose TWO of the three common indoor air pollutants (asbestos, radon, mold) listed above and complete the following table. (i) Identify a source for each indoor air pollutant. (ii) Describe a method for reducing exposure to each of the two pollutants you chose. Indoor Air Pollutant Source Method for Reducing Exposure STOP END OF EXAM © 2018 The College Board. Visit the College Board on the Web: www.collegeboard.org. -6- 2017 AP Environmental Science Free-Response Questions © 2017 The College Board. College Board, Advanced Placement Program, AP, AP Central, and the acorn logo are registered trademarks of the College Board. Visit the College Board on the Web: www.collegeboard.org. AP Central is the official online home for the AP Program: apcentral.collegeboard.org. 2017 AP® ENVIRONMENTAL SCIENCE FREE-RESPONSE QUESTIONS ENVIRONMENTAL SCIENCE SECTION II Time—90 minutes 4 Questions Directions: Answer all four questions, which are weighted equally; the suggested time is about 22 minutes for answering each question. Write all your answers on the pages following the questions in this book. Where calculations are required, clearly show how you arrived at your answer. Where explanation or discussion is required, support your answers with relevant information and/or specific examples. 1. Read the following article from the Fremont Daily Times and answer the questions that follow. © 2017 The College Board. Visit the College Board on the Web: www.collegeboard.org. -2- GO ON TO THE NEXT PAGE. 2017 AP® ENVIRONMENTAL SCIENCE FREE-RESPONSE QUESTIONS (a) Describe TWO effects that ingesting microbeads has on aquatic organisms. (b) Dr. Ewoldsen states that nitrates pose different threats to aquatic ecosystems than microbeads do. Describe how nitrate levels can negatively affect water quality in some aquatic ecosystems. (c) While wastewater treatment plants are ineffective at removing microbeads, they are very effective at removing large pieces of plastic waste and other pollutants. (i) Identify one way large pieces of plastic are removed from wastewater during primary treatment. (ii) Prior to discharge, wastewater is often disinfected. Identify one technique commonly used to disinfect wastewater. (iii) Sludge or biosolids produced during the wastewater treatment process can be spread on agricultural fields. Identify one advantage and one disadvantage of this practice. (d) Coastal ecosystems are threatened by other human activities in addition to wastewater disposal. Mangrove swamps are one such threatened ecosystem. (i) Provide one reason why mangrove trees are being removed by humans. (ii) Identify one ecosystem service provided by intact mangrove ecosystems. © 2017 The College Board. Visit the College Board on the Web: www.collegeboard.org. -3- GO ON TO THE NEXT PAGE. 2017 AP® ENVIRONMENTAL SCIENCE FREE-RESPONSE QUESTIONS 2. Populations of large terrestrial animals, such as African elephants and snow leopards, are in decline around the world. Many of these large animals are now on the verge of extinction. ESTIMATED AFRICAN ELEPHANT POPULATION ON THE AFRICAN CONTINENT Year Population 1970 2,000,000 1980 1,300,000 1990 600,000 1995 550,000 2000 400,000 2005 550,000 2010 650,000 2015 600,000 © 2017 The College Board. Visit the College Board on the Web: www.collegeboard.org. -4- GO ON TO THE NEXT PAGE. 2017 AP® ENVIRONMENTAL SCIENCE FREE-RESPONSE QUESTIONS (a) Using the data provided in the table above, plot the elephant population data as points on the grid below, placing the independent variable on the x-axis. Clearly label the axes. (b) Calculate the percent loss of elephants in Africa from 1970 to 2000. Show all work. (c) The International Union for Conservation of Nature (IUCN) estimates that the elephant population will decline by 20 percent between 2015 and 2022. Use this estimate to calculate how many elephants will be left in Africa in 2022. Show all work. (d) Most large terrestrial mammals are K-strategists. Identify one characteristic of a K-strategist and explain how the characteristic you identified can make these mammals prone to extinction. (e) Identify and discuss TWO conservation strategies that could be implemented to prevent the extinction of large terrestrial mammals, such as the African elephant or snow leopard. © 2017 The College Board. Visit the College Board on the Web: www.collegeboard.org. -5- GO ON TO THE NEXT PAGE. 2017 AP® ENVIRONMENTAL SCIENCE FREE-RESPONSE QUESTIONS 3. Haiti shares a border with the Dominican Republic on the Caribbean island of Hispaniola. (a) The border between the two countries can be seen using satellite images because of the severe deforestation in Haiti. (i) Provide one reason why deforestation commonly occurs in a less developed country such as Haiti. (ii) Describe one realistic strategy to reduce deforestation in a less developed country. (b) Deforestation can affect water quality. Identify one change that can occur in the water quality of streams within a watershed that has been deforested. Explain how deforestation can lead to this change. (c) Identify TWO environmental benefits, other than those related to water quality, of maintaining forest ecosystems. The table below contains demographic data for Haiti in 1995 and 2015. DEMOGRAPHIC DATA FOR HAITI Measure 1995 2015 Fertility rate (number of children per woman) 5.2 2.7 Life expectancy (years) 55 64 Infant mortality (deaths per 1,000) 85 48 (d) Identify and discuss one factor in a less developed country that could contribute significantly to a change in life expectancy, similar to what occurred in Haiti from 1995 to 2015. (e) Identify and discuss one economic or cultural factor in a less developed country that could contribute significantly to a change in the fertility rate, similar to what occurred in Haiti from 1995 to 2015. © 2017 The College Board. Visit the College Board on the Web: www.collegeboard.org. -6- GO ON TO THE NEXT PAGE. 2017 AP® ENVIRONMENTAL SCIENCE FREE-RESPONSE QUESTIONS 4. Dams are built by humans for various purposes including hydroelectric power generation and control of downstream flooding. (a) Explain how electricity is generated at a hydroelectric dam. (b) Identify TWO economic benefits, other than hydroelectric power generation and control of downstream flooding, associated with dams. (c) Describe one ecological benefit of seasonal flooding of the floodplain of a free-flowing river. (d) Some dams have been removed from rivers. (i) Explain how removal of a dam can benefit fish populations. (ii) Describe one negative environmental consequence of removing a dam from a river (other than effects on fish populations). (e) Dams are also built by beavers, a keystone species in some North American ecosystems. (i) Define keystone species. (ii) Describe how dams built by beavers can make beavers a keystone species in some ecosystems. STOP END OF EXAM © 2017 The College Board. Visit the College Board on the Web: www.collegeboard.org. -7- AP Environmental Science 2016 Free-Response Questions ® © 2016 The College Board. College Board, Advanced Placement Program, AP, AP Central, and the acorn logo are registered trademarks of the College Board. Visit the College Board on the Web: www.collegeboard.org. AP Central is the official online home for the AP Program: apcentral.collegeboard.org. "1¥&/7*30/.&/5"-4$*&/$&'3&&3&410/4&26&45*0/4 ENVIRONMENTAL SCIENCE SECTION II Time—90 minutes 4 Questions Directions: Answer all four questions, which are weighted equally; the suggested time is about 22 minutes for answering each question. Write all your answers on the pages following the questions in this book. Where calculations are required, clearly show how you arrived at your answer. Where explanation or discussion is required, support your answers with relevant information and/or specific examples. 1. Read the following article from the Fremont New Tribune. © 2016 The College Board. Visit the College Board on the Web: www.collegeboard.org. GO ON TO THE NEXT PAGE. -2- "1¥&/7*30/.&/5"-4$*&/$&'3&&3&410/4&26&45*0/4 (a) Diseases can devastate populations; however, most diseases do not drive their host to extinction. Provide one explanation for why diseases seldom cause extinction. (b) Dr. Serach suggests that even if the impact of WNS on little brown bat populations can be reduced and the extinction of the species avoided, the bat populations are likely to remain alarmingly small. (i) Describe TWO threats (other than WNS) to the survival of the bat species if the total number of bats becomes very small. (ii) If the little brown bat species does not become extinct and can potentially recover, the rate of recovery is likely to be slow. Discuss one aspect of bat biology that might slow the recovery of little brown bat populations to pre-WNS numbers. (c) Bats are found in ecosystems around the world. Describe TWO ways in which other organisms in an ecosystem could be affected by a decline in a bat population. (d) The Eastern deciduous forest in which the little brown bats live is an important ecosystem. Identify TWO ecosystem services that forests provide, and explain how each service benefits human society. WNS is an emerging disease in bats. Humans are also subject to emerging diseases, such as Ebola. A recent study suggests that the number of emerging infectious diseases affecting human populations has been steadily increasing in recent decades. (e) Provide a likely reason for the increase in emerging infectious diseases affecting human populations. Include an explanation for the reason you provided. © 2016 The College Board. Visit the College Board on the Web: www.collegeboard.org. GO ON TO THE NEXT PAGE. -3- "1¥&/7*30/.&/5"-4$*&/$&'3&&3&410/4&26&45*0/4 2. Iron ores are rocks from which metallic iron can be extracted for steel production. This process involves several steps. Iron ore is first mined and then turned into pig iron in a blast furnace, and some rock waste such as silicon dioxide is separated out. In the final step, the pig iron is refined into steel using a process that includes reacting the molten pig iron with oxygen to remove impurities. (a) Use the data below to respond to the following. For each calculation, show all your work. Global Iron and Steel Data 1.6 billion tons of iron ore are used yearly to make pig iron. 1.2 billion tons of pig iron are produced each year. Iron ore reserves are estimated to be 800 billion tons. 95% of iron ore that is mined is used in steel production. (i) Calculate the weight (in tons) of rock waste produced globally each year when iron ore is converted to pig iron. (ii) Calculate the weight (in tons) of pig iron that could be produced if all of the estimated global iron ore reserves were used for pig iron production. (iii) Calculate the weight (in tons) of the current global iron ore reserves that would be used to make steel if the current trends continue. Both iron ore and coal are mined for use in the manufacture of steel. It is estimated that for every ton of steel recycled, 1.25 fewer tons of iron ore and 0.7 fewer tons of coal must be mined. About 80 million tons of steel are recycled each year in North America. (b) Calculate the weight (in tons) of coal that is conserved each year in North America by recycling steel. Before the year 1900, most mining companies abandoned surface and subsurface coal mine sites once the resource was depleted. (c) Describe TWO environmental problems that are associated with abandoned coal mine sites. (d) Describe one method that can be used to mitigate one of the problems you identified in part (c). (e) Discuss one reason why surface coal mining is generally less expensive than subsurface mining. © 2016 The College Board. Visit the College Board on the Web: www.collegeboard.org. GO ON TO THE NEXT PAGE. -4- "1¥&/7*30/.&/5"-4$*&/$&'3&&3&410/4&26&45*0/4 3. Municipal solid waste (MSW) is the trash collected from households and businesses. The graph below shows MSW generation in the United States from 1960 to 2012. (a) Use the data provided in the graph above to respond to the following. (i) Explain one probable cause (other than increased composting) for the change in per capita waste generation from 2000 to 2012. (ii) Calculate the percent increase in total MSW generation from 1980 to 2012. (b) Two ways of managing MSW are incineration and disposal in landfills. (i) Identify one disadvantage of waste incineration. (ii) Identify one disadvantage of waste disposal in landfills. Trash incineration is one way to generate electricity from MSW. Electricity can also be generated from waste buried in landfills. (c) Describe the specific steps of a process used to produce electricity from waste buried in a landfill. (d) Many landfills do not accept used tires. As a result, the tires are often dumped in poorly regulated piles. Describe one human health problem associated with piles of discarded tires. (e) Composting is one way to reduce the amount of waste that enters a landfill. (i) Other than reducing the volume of waste, identify one advantage of composting. (ii) Identify one disadvantage of composting. © 2016 The College Board. Visit the College Board on the Web: www.collegeboard.org. GO ON TO THE NEXT PAGE. -5- "1¥&/7*30/.&/5"-4$*&/$&'3&&3&410/4&26&45*0/4 4. Soil is a complex mixture of living organisms and organic material, along with minerals and other abiotic components. Soils help sustain life and support ecosystem functions. (a) Describe how TWO climate factors affect the rate of soil formation. (b) As soils form, distinct layers known as horizons develop over time. One of these is the A horizon. (i) Identify one specific biotic component of the A horizon. (ii) Identify one abiotic component of the A horizon. Resources such as soil and water can be degraded by human activities. (c) Nitrate levels exceeding the United States Environmental Protection Agency’s primary drinking water standard have been found in the groundwater of areas with intensive agriculture. (i) Identify one agricultural practice that can lead to elevated nitrate levels in groundwater. (ii) Describe how the practice you identified in (c)(i) leads to elevated nitrate levels in groundwater. (d) Acid deposition has affected soil quality in many parts of the northeastern United States. (i) Explain one way acid deposition onto soil can affect plant health. (ii) Describe one method for remediating soil affected by acid deposition. (e) Climate change is causing far-reaching ecosystem changes, including soil degradation in many of the world’s biomes. Describe TWO ways that climate change can degrade soil. STOP END OF EXAM © 2016 The College Board. Visit the College Board on the Web: www.collegeboard.org. -6- AP Environmental Science 2015 Free-Response Questions ® © 2015 The College Board. College Board, Advanced Placement Program, AP, AP Central, and the acorn logo are registered trademarks of the College Board. Visit the College Board on the Web: www.collegeboard.org. AP Central is the official online home for the AP Program: apcentral.collegeboard.org. 2015 AP® ENVIRONMENTAL SCIENCE FREE-RESPONSE QUESTIONS ENVIRONMENTAL SCIENCE SECTION II Time— 90 minutes 4 Questions Directions: Answer all four questions, which are weighted equally; the suggested time is about 22 minutes for answering each question. Write all your answers on the pages following the questions in this book. Where calculations are required, clearly show how you arrived at your answer. Where explanation or discussion is required, support your answers with relevant information and/or specific examples. 1. Read the article below and answer the questions that follow. (a) Describe how TWO human activities, other than those that result in anthropogenic climate change, have resulted in a decrease in the amount of freshwater flowing into the Everglades ecosystem. (b) In addition to water quantity problems, the Everglades is faced with a variety of water quality issues. For example, phosphorus concentrations in the Everglades have increased since the 1960s. (i) Describe how one specific human activity contributes to increased phosphorus levels in the Everglades. (ii) Explain one way in which an increase in phosphorus levels can adversely affect the Everglades ecosystem. (iii) Describe one step that could be taken to reduce phosphorus inputs from the activity you identified in part (i). (c) Climate change could have a variety of impacts on water quantity, water quality, and habitat. For EACH of these three factors, identify and describe one specific example of an impact on the Everglades likely to result from climate change. (d) The article states that Governor Moss believes that the “preservation and enhancement of the Everglades, key goals of the restoration program, are absolutely essential for the continued environmental and economic health of the state.” (i) Describe one way that restoring water quantity and water quality in the Everglades is expected to improve the structure and function of the ecosystem. (ii) Describe one way that restoring the Everglades is expected to provide economic benefits to Florida. © 2015 The College Board. Visit the College Board on the Web: www.collegeboard.org. GO ON TO THE NEXT PAGE. -2- 2015 AP® ENVIRONMENTAL SCIENCE FREE-RESPONSE QUESTIONS 2. Approximately 30 million mobile devices were sold in 1998 in the United States. The number sold increased to 180 million devices in 2007. (a) Calculate the percent increase of mobile device sales from 1998 to 2007. (b) Each mobile device sold in 2007 contained an average of 0.03 gram of gold. Calculate the number of grams of gold that were used in the production of the mobile devices sold in 2007. (c) Assume that the average mass of each mobile device was 0.1 kilogram. The United States Environmental Protection Agency estimates that about 10 percent of the mobile devices sold in 2007 were recycled. Calculate the mass (in kilograms) of the mobile devices sold in 2007 that were not recycled. (d) Discarded mobile devices become part of the electronic waste stream (e-waste). Mercury is often present in e-waste. Identify one negative human health effect, other than death, associated with exposure to mercury. (e) Improper disposal of e-waste has harmed human health and caused environmental damage in developing countries. (i) State TWO reasons why large quantities of e-waste from the United States are shipped to developing countries rather than being recycled in the United States. (ii) Retailers or manufacturers could take specific steps to dramatically reduce the amount of e-waste. Describe a realistic change in current practices that would accomplish this. © 2015 The College Board. Visit the College Board on the Web: www.collegeboard.org. GO ON TO THE NEXT PAGE. -3- 2015 AP® ENVIRONMENTAL SCIENCE FREE-RESPONSE QUESTIONS 3. Oil spills can be devastating in scope and damage. Since 1900, there have been many oil spills around the world that have had significant ecological and economic impacts. (a) Using the data in the graph above, determine the maximum volume of oil estimated to have been spilled during the Deepwater Horizon (BP) incident. (b) Describe TWO environmental problems that can result from oil spills in coastal areas. (c) Identify one economic impact that results from oil spills in coastal areas. (d) Chemical dispersants have been used in cleanup efforts following major oil spills. (i) Discuss both one advantage and one disadvantage of the use of chemical dispersants for oil spill cleanup. (ii) Identify either one biological or one physical method (other than chemical dispersal) used for oil spill cleanup in coastal waters or on beaches and describe how the method is used. (e) Catastrophic spills make up less than 20 percent of the oil that pollutes marine waters. Identify one other source of oil contamination and explain how the oil from this source enters marine waters. (f) Petroleum has many uses as a raw material for consumer goods. Identify one substitute for petroleum in a specific consumer product (other than fuel). © 2015 The College Board. Visit the College Board on the Web: www.collegeboard.org. GO ON TO THE NEXT PAGE. -4- 2015 AP® ENVIRONMENTAL SCIENCE FREE-RESPONSE QUESTIONS 4. The term “urban sprawl” describes the expansion of cities into rural areas. This phenomenon has occurred around the world and has had economic, health, and environmental consequences. (a) Describe TWO causes of urban sprawl. (b) Discuss TWO human health effects associated with urban sprawl. (c) The graph below shows the relationship between population density and petroleum use in selected cities. Describe the relationship between population density and petroleum use shown in the graph. (d) Smart growth focuses on ways to encourage sustainable urban development. Describe TWO steps a municipality could take to encourage smart growth in order to limit urban sprawl. (e) Highway systems and urban sprawl often threaten wildlife populations. Describe TWO methods to reduce harmful effects on wildlife populations from highways and urban sprawl. (f) Urban sprawl often results in the loss of productive agricultural land near cities. Describe one practical way to increase food production within urban areas. STOP END OF EXAM © 2015 The College Board. Visit the College Board on the Web: www.collegeboard.org. -5- AP Environmental Science 2014 Free-Response Questions ® © 2014 The College Board. College Board, Advanced Placement Program, AP, AP Central, and the acorn logo are registered trademarks of the College Board. Visit the College Board on the Web: www.collegeboard.org. AP Central is the official online home for the AP Program: apcentral.collegeboard.org. 2014 AP® ENVIRONMENTAL SCIENCE FREE-RESPONSE QUESTIONS ENVIRONMENTAL SCIENCE SECTION II Time— 90 minutes 4 Questions Directions: Answer all four questions, which are weighted equally; the suggested time is about 22 minutes for answering each question. Write all your answers on the pages following the questions in this book. Where calculations are required, clearly show how you arrived at your answer. Where explanation or discussion is required, support your answers with relevant information and/or specific examples. 1. Read the article below and answer the questions that follow. (a) State whether you agree or disagree with each of the following remarks made by Dr. Kull. For each remark, provide one justification for your position. (i) “Nuclear power plants produce no dangerous solid waste.” (ii) “Using nuclear power avoids the release of greenhouse gases.” (b) If the plan for a nuclear power plant in Fremont is approved, it will take several years for the plant to be built. Describe TWO environmental problems that could result from the construction of the plant (i.e., prior to operation). (c) Suppose that the nuclear power plant is constructed on the Fremont River site. (i) Identify the most likely pollution threat that the plant will pose to the Fremont River as a result of the plant’s normal daily operation. (ii) Discuss one potential ecological consequence of the pollution threat that you identified in part (i). (iii) Identify a system often used in nuclear power plants to reduce the pollution you identified in part (i). (d) Describe TWO specific steps that Fremont residents and/or businesses could take to reduce the use of electricity. (e) Identify a specific nuclear power plant at which a major accident has occurred. Explain one environmental consequence (other than effects on human health) of a nuclear power plant accident. © 2014 The College Board. Visit the College Board on the Web: www.collegeboard.org. GO ON TO THE NEXT PAGE. -2- 2014 AP® ENVIRONMENTAL SCIENCE FREE-RESPONSE QUESTIONS 2. Like many communities, Fremont has a combined sewer system that collects both sewage and storm water. When storm water runs into storm drains that connect to the city’s sanitary sewer system, the storm water and sewage flow together to the Fremont Wastewater Treatment Plant (FWTP). During a major storm event, however, the combined volume of storm water and sewage may exceed the plant’s capacity, and the overflow bypasses the FWTP. The untreated overflow is discharged into Fremont Creek along with the treated waste. Recently parts of Fremont received 5 cm of rain in 60 minutes. The storm caused widespread flooding in the northeast section of town. Especially hard hit was the Shoppes at Fremont shopping center. Use the data from the table below to answer the questions that follow. Show all calculations. Fremont Water Data The shopping center’s parking lot is 200 meters long and 100 meters wide. 2 Fremont has an area of 10 km . Impervious surfaces cover 20 percent of Fremont’s area. 3 The FWTP typically treats 5,000 m of domestic sewage per day. 3 The FWTP has the capacity to treat 10,000 m of combined sewage and storm water per day. (a) Identify TWO specific pollutants in storm-water runoff that degrade the quality of surface water. 3 (b) Calculate the volume of water (in m ) that runs off the Shoppes at Fremont parking lot after a 5 cm rainfall event. Assume that all the water that falls on the parking lot runs off. 3 (c) Calculate the volume of storm-water runoff (in m ) generated in all of Fremont by the 5 cm rainfall event. Assume that only the impervious surfaces generate runoff. (d) Assume that all the runoff that you calculated in part (c) is captured by the storm sewers in one day. 3 Calculate the volume of untreated water (in m ) that bypasses the plant as a result of the storm. (Note that 3 the plant still receives 5,000 m of domestic sewage per day.) (e) Describe TWO ways that the volume of storm-water runoff can be reduced. (f) Describe one environmental problem (other than pollution from runoff and from untreated sewage) that results from having extensive paved areas. © 2014 The College Board. Visit the College Board on the Web: www.collegeboard.org. GO ON TO THE NEXT PAGE. -3- 2014 AP® ENVIRONMENTAL SCIENCE FREE-RESPONSE QUESTIONS 3. Plate-tectonic theory states that the Earth’s lithosphere is broken into very slowly moving pieces or plates. Plate movements over vast stretches of time have led to the current orientation of our continents and oceans. Individual events along plate boundaries, such as earthquakes and volcanic eruptions, pose periodic threats to human activity and ecosystems. The “Ring of Fire” is a term that describes the location of increased seismic and volcanic activity around the margins of the Pacific Ocean basin. On the map above, each dot represents a volcano or an earthquake. (a) Japan, Indonesia, and the Philippines are examples of volcanic island chains that have formed along subduction zones between plates in the western Pacific. (i) Describe what happens when two tectonic plates collide along a subduction zone. (ii) Explain how subduction leads to volcanic activity. (b) Although the landscape following a volcanic eruption may appear unable to support ecological communities, over time the area can be transformed through succession. (i) What is primary succession? (ii) Explain how primary succession can lead to soil formation on a newly formed volcanic landscape. (c) In addition to volcanic activity, highly destructive tsunamis are generated along Pacific Plate subduction zones. (i) Explain how a tsunami is generated along a subduction zone. (ii) Describe one negative ecological impact that tsunamis have on coastal environments. (d) Southern California experiences periodic devastating earthquakes along the San Andreas Fault, which is a transform boundary located along the eastern edge of the Pacific Plate. (i) Describe what happens to the tectonic plates along a transform boundary at the moment when an earthquake occurs. (ii) Describe what happens to the tectonic plates along a transform boundary during the time between earthquakes. © 2014 The College Board. Visit the College Board on the Web: www.collegeboard.org. GO ON TO THE NEXT PAGE. -4- 2014 AP® ENVIRONMENTAL SCIENCE FREE-RESPONSE QUESTIONS 4. Biogeochemical cycles describe the movement of certain elements (typically bound with other elements in compounds) through Earth’s atmosphere, hydrosphere, biosphere, and lithosphere. These elements and their compounds are necessary components of all life, and because they cycle, they can be used repeatedly by new generations of organisms. Each biogeochemical cycle has different pathways with various reservoirs (sources and sinks) where elements may reside for days or millions of years. (a) The atmosphere is one important carbon reservoir. (i) Describe a biological process by which carbon is removed from the atmosphere and converted to organic molecules. (ii) Describe a biological process by which carbon is converted from organic molecules to a gas and returned to the atmosphere. (b) Oceans and terrestrial systems are also important carbon reservoirs. (i) Explain how atmospheric carbon is incorporated into two oceanic sinks. (ii) Identify one terrestrial sink, other than fossil fuels, that stores carbon for thousands to millions of years. (c) The burning of fossil fuels has been shown to increase the concentration of carbon in the atmosphere. Discuss TWO other human activities that increase the concentration of carbon in the atmosphere. (d) Identify an environmental problem that results from elevated atmospheric carbon concentrations. Discuss one consequence of the problem you identified. (e) Phosphorus is another element important to all organisms. (i) Describe one major way in which the phosphorus cycle differs from the carbon cycle. (ii) Identify one reason that phosphorus is necessary for organisms. STOP END OF EXAM © 2014 The College Board. Visit the College Board on the Web: www.collegeboard.org. -5- AP® Environmental Science 2013 Free-Response Questions About the College Board The College Board is a mission-driven not-for-profit organization that connects students to college success and opportunity. Founded in 1900, the College Board was created to expand access to higher education. Today, the membership association is made up of more than 6,000 of the world’s leading educational institutions and is dedicated to promoting excellence and equity in education. Each year, the College Board helps more than seven million students prepare for a successful transition to college through programs and services in college readiness and college success — including the SAT® and the Advanced Placement Program®. The organization also serves the education community through research and advocacy on behalf of students, educators, and schools. © 2013 The College Board. College Board, Advanced Placement Program, AP, AP Central, SAT, and the acorn logo are registered trademarks of the College Board. Admitted Class Evaluation Service and inspiring minds are trademarks owned by the College Board. All other products and services may be trademarks of their respective owners. Visit the College Board on the Web: www.collegeboard.org. Permission to use copyrighted College Board materials may be requested online at: www.collegeboard.org/inquiry/cbpermit.html. Visit the College Board on the Web: www.collegeboard.org. AP Central is the official online home for the AP Program: apcentral.collegeboard.org. 2013 AP® ENVIRONMENTAL SCIENCE FREE-RESPONSE QUESTIONS ENVIRONMENTAL SCIENCE SECTION II Time— 90 minutes 4 Questions Directions: Answer all four questions, which are weighted equally; the suggested time is about 22 minutes for answering each question. Write all your answers on the pages following the questions in this book. Where calculations are required, clearly show how you arrived at your answer. Where explanation or discussion is required, support your answers with relevant information and/or specific examples. 1. (a) Identify TWO human activities that alter the natural flow of sediments into Gulf Coast ecosystems. Explain how each of the activities alters the flow of sediments. (b) Dr. James says that it is important to restore sediments. Describe TWO ways that the loss of natural sediment harms Gulf Coast wetland ecosystems. (c) Dr. James also indicates that it is necessary to limit fertilizer runoff into the Mississippi River. i. Describe TWO environmental impacts on the marine ecosystem that are caused by fertilizer when it flows into the Gulf of Mexico. ii. What are TWO economic consequences that result from the flow of fertilizer into the Gulf of Mexico? iii. Describe ONE strategy, other than reducing the use of fertilizer, that can be employed to reduce the flow of nutrients into the Mississippi River. © 2013 The College Board. Visit the College Board on the Web: www.collegeboard.org. GO ON TO THE NEXT PAGE. -2- 2013 AP® ENVIRONMENTAL SCIENCE FREE-RESPONSE QUESTIONS 2. Battery electric vehicles (BEVs) have been introduced to consumers as an alternative way to reduce the environmental effects caused by use of internal-combustion engine (ICE) vehicles. A comparison of both vehicle types can help determine whether the use of BEVs would be beneficial in the future. Where calculations are required, show your work. (a) Identify THREE strategies that the federal government could implement to encourage the use of BEVs. (b) Assume that the fuel efficiency of the ICE vehicle is 25 miles per gallon (mpg) and that gasoline costs $3.75 per gallon (gal). Calculate the cost of gasoline per mile. (c) The charger supplies energy to the BEV battery at an average rate of 4.0 kilowatts (kW) and fully charges the BEV battery in 7.0 hours. The car will run for 100 miles on a full charge. The cost of electricity is $0.11 per kilowatt-hour (kWh). i. Calculate the cost of the electricity to fully charge the battery. Assume that the battery is not charged to begin with. ii. Calculate the cost of electricity per mile to drive the BEV. When it is driven 100 miles, the ICE vehicle contributes 72.8 pounds (lb) of CO 2 from the burning of the gasoline. The drilling, refining, and transportation costs of getting the gasoline to the gas station add an additional 17.7 lb of CO2 per 100 miles. The BEV does not emit any CO 2 itself, but the extraction, transportation, and combustion of the coal that produced the electricity at the power plant add 63.6 lb of CO 2 for the same 100 miles. (d) Calculate the difference in the amount of CO2 that would enter the atmosphere if both cars were driven 100 miles. (e) Describe TWO economic impacts (excluding costs related to climate change resulting from CO2 emissions or the cost of gasoline at the pump) that result from an increased number of BEVs on the road. © 2013 The College Board. Visit the College Board on the Web: www.collegeboard.org. GO ON TO THE NEXT PAGE. -3- 2013 AP® ENVIRONMENTAL SCIENCE FREE-RESPONSE QUESTIONS 3. Ozone O3 is an atmospheric trace gas that occurs naturally in the stratosphere. It is also formed as a consequence of human activity in the troposphere, immediately above Earth’s surface. The location of ozone in the atmosphere determines whether the gas protects or damages the environment. (a) Identify the type of solar radiation that is absorbed by stratospheric ozone, and describe one human health benefit that results from the absorption of this solar energy. (b) The absorption of solar energy by stratospheric ozone causes ozone molecules to undergo chemical decomposition and formation. Describe the chemical processes that lead to this natural balance between decomposition and formation of stratospheric ozone (you may use chemical equations in your answer). (c) The Montreal Protocol of 1987 provided a global framework to phase out chlorofluorocarbon (CFC) production and use. Although the Montreal Protocol has led to a dramatic decrease in CFCs released into the atmosphere, stratospheric ozone destruction has decreased only slightly. i. Explain the process by which CFCs lead to the destruction of stratospheric ozone. (You may use chemical equations in your answer.) ii. Explain why the rapid decrease in CFC emissions has not led to a similarly rapid decrease in the destruction of stratospheric ozone. (d) Identify a human activity that leads to the formation of tropospheric ozone as a secondary pollutant and explain why tropospheric ozone levels peak in the daytime. (e) Identify one negative ecological impact and one negative human health impact that result from the formation of tropospheric ozone. © 2013 The College Board. Visit the College Board on the Web: www.collegeboard.org. GO ON TO THE NEXT PAGE. -4- 2013 AP® ENVIRONMENTAL SCIENCE FREE-RESPONSE QUESTIONS 4. Biological diversity, or biodiversity, has become a topic of great concern among conservationists. Biodiversity is often used by scientists and policy makers to help determine the health of ecosystems. (a) Describe TWO characteristics shared by ecosystems that have high biodiversity. (b) Identify TWO specific human activities that result in a loss of biodiversity, and explain how each activity lowers biodiversity. (c) For each human activity you discussed in (b), propose a practical strategy (other than simply banning the activity) to reduce the loss of biodiversity. (d) Describe ONE naturally occurring factor that could lead to a loss of biodiversity. (e) Describe TWO ecological benefits that greater biodiversity provides. STOP END OF EXAM © 2013 The College Board. Visit the College Board on the Web: www.collegeboard.org. -5- AP® Environmental Science 2012 Free-Response Questions About the College Board The College Board is a mission-driven not-for-profit organization that connects students to college success and opportunity. Founded in 1900, the College Board was created to expand access to higher education. Today, the membership association is made up of more than 5,900 of the world’s leading educational institutions and is dedicated to promoting excellence and equity in education. Each year, the College Board helps more than seven million students prepare for a successful transition to college through programs and services in college readiness and college success — including the SAT® and the Advanced Placement Program®. The organization also serves the education community through research and advocacy on behalf of students, educators, and schools. © 2012 The College Board. College Board, Advanced Placement Program, AP, AP Central, SAT, and the acorn logo are registered trademarks of the College Board. Admitted Class Evaluation Service and inspiring minds are trademarks owned by the College Board. All other products and services may be trademarks of their respective owners. Visit the College Board on the Web: www.collegeboard.org. Permission to use copyrighted College Board materials may be requested online at: www.collegeboard.org/inquiry/cbpermit.html. Visit the College Board on the Web: www.collegeboard.org. AP Central is the official online home for the AP Program: apcentral.collegeboard.org. 2012 AP® ENVIRONMENTAL SCIENCE FREE-RESPONSE QUESTIONS ENVIRONMENTAL SCIENCE SECTION II Time— 90 minutes 4 Questions Directions: Answer all four questions, which are weighted equally; the suggested time is about 22 minutes for answering each question. Write all your answers on the pages following the questions in this book. Where calculations are required, clearly show how you arrived at your answer. Where explanation or discussion is required, support your answers with relevant information and/or specific examples. 1. Read the following article from the Fremont Gazette and answer the questions that follow. (a) Identify and describe TWO water-related environmental problems associated with fracking. (b) Natural gas is considered to be a better fossil fuel for the environment than coal is. Discuss TWO environmental benefits of using natural gas as a fuel compared to using coal. (c) Describe TWO environmental drawbacks, not related to water use, of using the fracking process to extract natural gas from shale. (d) Describe one economic benefit to society of using fracking to obtain natural gas from shale. (e) Nuclear power is an alternative to using natural gas or coal as a fuel for generating electricity. However, there are also problems associated with nuclear power plants. Describe TWO negative environmental impacts associated with nuclear power. © 2012 The College Board. Visit the College Board on the Web: www.collegeboard.org. GO ON TO THE NEXT PAGE. -2- 2012 AP® ENVIRONMENTAL SCIENCE FREE-RESPONSE QUESTIONS 2. The Fremont School District uses oil to heat school buildings. Go Green! is a new project the district will implement. The superintendent has declared that the district will dedicate itself to reducing its carbon footprint. In addition to taking serious energy-conservation measures, the district is planning to help offset its carbon dioxide emissions by raising money to help conserve a portion of a large tract of forest land adjacent to the high school campus. (a) Describe one alternative energy source that would reduce the carbon footprint of the school district. Discuss one environmental benefit (other than reduced CO2 emissions) and one environmental drawback of using the alternative source instead of fuel oil. (b) Identify TWO ecological benefits provided by intact forest ecosystems (other than reducing CO2 levels in the atmosphere). (c) Use the assumptions below to answer the questions that follow. For each calculation, show all work. The biomass of the forest increases at an annual rate of 2.7 × 105 kg/ha. The forest biomass is 50 percent carbon by mass. Each year the district uses 3.0 × 105 gallons of fuel oil for heating and hot water. 10 kg of CO2 is produced when 1 gallon of fuel oil is burned. 1.0 kg of CO2 contains 0.27 kg of carbon. The cost of putting 1 ha of the forest into conservancy is $12,000. (i) Calculate the mass of carbon, in kg, that is accumulated and stored in 1.0 ha of forest in one year. (ii) Calculate the mass of carbon, in kg, that is emitted by the school as a result of its fuel-oil consumption in one year. (iii) Calculate the number of hectares of forest the school district needs to conserve in order to offset the carbon released in one year by the school burning its fuel oil. (iv) Calculate the amount of money the school district must raise for the conservation project. © 2012 The College Board. Visit the College Board on the Web: www.collegeboard.org. GO ON TO THE NEXT PAGE. -3- 2012 AP® ENVIRONMENTAL SCIENCE FREE-RESPONSE QUESTIONS 3. The active ingredients in many pesticides are chemical compounds that kill organisms such as insects, molds, and weeds. Proponents claim that the use of pesticides improves crop yields and thus protects land and soil by reducing the conversion of forests and wetlands to cropland. Opponents of pesticide use claim that pesticides degrade water and soil quality and that other modern agricultural techniques and practices are responsible for the improved crop yields in recent years. (a) Design a laboratory experiment to determine whether or not a new pesticide (product X) is toxic to minnows, a type of small fish. For the experiment you design, be sure to do all of the following. (i) State the hypothesis. (ii) Describe the method you would use to test your hypothesis. (iii) Identify the control. (iv) Identify the dependent variable. (b) Describe experimental results that would lead you to reject your hypothesis in part (a)(i). (Be specific.) (c) One strategy for dealing with agricultural pests is integrated pest management (IPM). (i) Describe IPM. As part of your description, include TWO specific pest-control approaches that are part of IPM. (ii) Identify one environmental benefit of using IPM. (d) Describe TWO agricultural practices, other than those involving pest control, that increase crop yields. © 2012 The College Board. Visit the College Board on the Web: www.collegeboard.org. GO ON TO THE NEXT PAGE. -4- 2012 AP® ENVIRONMENTAL SCIENCE FREE-RESPONSE QUESTIONS 4. Wetlands were once considered to be wastelands. Over 50 percent of the United States original wetlands have been destroyed. (a) Describe TWO characteristics that are used by scientists to define an area as a wetland. (b) Wetlands are highly productive ecosystems with complex food webs. (i) Complete the diagram of the wetland food web below by drawing arrows that show the direction of energy flow. (ii) Explain why it takes many hectares of wetland to support a pair of eagles. (c) Describe TWO economic benefits (other than those related to water quality) that wetlands provide. (d) Describe one specific human activity that degrades wetlands. (e) Wastewater treatment plants perform some of the same water-quality improvement functions that natural wetlands perform. Explain how wetlands perform the equivalent of (i) primary treatment, and (ii) secondary treatment. STOP END OF EXAM © 2012 The College Board. Visit the College Board on the Web: www.collegeboard.org. -5- AP® Environmental Science 2011 Free-Response Questions About the College Board The College Board is a mission-driven not-for-profit organization that connects students to college success and opportunity. Founded in 1900, the College Board was created to expand access to higher education. Today, the membership association is made up of more than 5,900 of the world’s leading educational institutions and is dedicated to promoting excellence and equity in education. Each year, the College Board helps more than seven million students prepare for a successful transition to college through programs and services in college readiness and college success — including the SAT® and the Advanced Placement Program®. The organization also serves the education community through research and advocacy on behalf of students, educators and schools. © 2011 The College Board. College Board, Advanced Placement Program, AP, AP Central, SAT and the acorn logo are registered trademarks of the College Board. Admitted Class Evaluation Service and inspiring minds are trademarks owned by the College Board. All other products and services may be trademarks of their respective owners. Visit the College Board on the Web: www.collegeboard.org. Permission to use copyrighted College Board materials may be requested online at: www.collegeboard.org/inquiry/cbpermit.html. Visit the College Board on the Web: www.collegeboard.org. AP Central is the official online home for the AP Program: apcentral.collegeboard.com. 2011 AP® ENVIRONMENTAL SCIENCE FREE-RESPONSE QUESTIONS ENVIRONMENTAL SCIENCE SECTION II Time— 90 minutes 4 Questions Directions: Answer all four questions, which are weighted equally; the suggested time is about 22 minutes for answering each question. Write all your answers on the pages following the questions in the pink booklet. Where calculations are required, clearly show how you arrived at your answer. Where explanation or discussion is required, support your answers with relevant information and/or specific examples. 1. Read the following article from the Fremont Inquirer and answer the questions that follow. (a) As mentioned in the article, there are several possible explanations for the increase in mountain pine beetles. (i) Provide one reason why fire-suppression policies lead to increased beetle activity. (ii) Reduced winter mortality of beetle larvae is likely a consequence of global climate change. Describe TWO ways that the activities of the beetles might enhance climate change. © 2011 The College Board. Visit the College Board on the Web: www.collegeboard.org. GO ON TO THE NEXT PAGE. -2- 2011 AP® ENVIRONMENTAL SCIENCE FREE-RESPONSE QUESTIONS (b) The widespread death of trees leads to a series of changes in a forest ecosystem. Identify TWO physical changes that occur in the forest ecosystem as the result of the death of mature trees. For each physical change you identify, describe an impact of that change on the forest ecosystem. (c) As the article states, the number of managed honeybee colonies has dropped significantly over the past few decades. Describe TWO specific economic consequences of the collapse of the managed honeybee colonies. (d) Pollination by native insects is considered an ecosystem service. Identify a different ecosystem service and explain how that service benefits human society. 2. Coral reefs are produced when corals acquire calcium ions (Ca2+) and carbonate ions (CO32−) from seawater and deposit solid CaCO3 to form their exoskeletons. Scientists are concerned that relatively rapid decreases in ocean water pH will hinder the deposition of CaCO3. The graph above shows the amount of CO2 dissolved in ocean water and ocean water pH (shown in parentheses) since 1850 and the predicted changes through 2100. (a) Explain how an increase in the amount of dissolved CO2 in ocean water results in a decrease in the pH of ocean water. (b) Explain why the movement of carbon into the ocean has been increasing since 1850. © 2011 The College Board. Visit the College Board on the Web: www.collegeboard.org. GO ON TO THE NEXT PAGE. -3- 2011 AP® ENVIRONMENTAL SCIENCE FREE-RESPONSE QUESTIONS (c) In order to model the effects of ocean acidification on coral reefs, some simplifying assumptions can be made. Use the assumptions in the table below to perform the calculations that follow. Assume that the total global area of corals growing in reefs is 2.5 × 1011 m2. Assume that corals grow only vertically and that the average vertical growth rate of corals is 3 mm/year. Assume that the average density of CaCO3 in corals is 2 × 103 kg/m3. (i) Calculate the current annual global increase in volume, in m3, of CaCO3 in coral reefs. Show all steps in your calculation. (ii) Calculate the current annual global increase in mass, in kg, of CaCO3 in coral reefs. Show all steps in your calculation. (iii) Because of ocean acidification, it is expected that in 2050 the mass of CaCO3 deposited annually in coral reefs will be 20 percent less than is deposited currently. Calculate how much less CaCO3 , in kg, is expected to be deposited in 2050 than would be deposited if ocean water pH were to remain at its current value. (d) Identify and describe one likely negative environmental impact of the loss of coral reefs. (e) Identify one environmental problem (other than one due to ocean acidification or loss of coral reefs) that affects marine ecosystems on a global scale. © 2011 The College Board. Visit the College Board on the Web: www.collegeboard.org. GO ON TO THE NEXT PAGE. -4- 2011 AP® ENVIRONMENTAL SCIENCE FREE-RESPONSE QUESTIONS 3. Shown above is a graph of the gross domestic product (GDP) per capita versus the annual electrical energy consumption per capita for nine countries in 2009. (a) Iceland’s position on the graph is due in part to its access to geothermal energy sources. Describe how electricity is generated from a geothermal source. (b) Despite its low GDP per capita and low annual electrical energy consumption per capita, China has become the world’s largest emitter of CO2 . Explain this apparent contradiction. (c) In addition to contributing to increased atmospheric CO2 concentrations, China is facing other air pollution issues related to the generation of electricity. Identify one such issue and describe the impact it has on human health. (d) Two countries shown on the graph have developed domestic energy sources: sugarcane in Brazil and tar sands in western Canada. (i) Choose EITHER sugarcane or tar sands, then briefly describe the process of fuel production from that energy source. (ii) Describe TWO disadvantages of using the energy source that you chose in part (d)(i). (iii) Which of the two energy sources is more sustainable? Justify your answer with an explanation. © 2011 The College Board. Visit the College Board on the Web: www.collegeboard.org. GO ON TO THE NEXT PAGE. -5- 2011 AP® ENVIRONMENTAL SCIENCE FREE-RESPONSE QUESTIONS 4. As the world’s population increases and availability of new arable land decreases, providing sufficient food for the world’s human population is becoming increasingly difficult. The table below shows the area of land needed to feed the world’s population from 1900 projected to the year 2060. Year 1900 1940 1980 2020 2060 Land Area Needed (billion hectares) 0.40 0.60 1.25 2.50 4.75 (a) On the graph below, plot the data from the table above and draw a smooth curve. (b) Assume that the maximum arable land area on Earth is 4.00 billion hectares. Using the smooth curve that you created above, determine the year in which the human population is likely to run out of arable land for agriculture. (c) Soil quality is a critical factor in agriculture. Identify TWO physical and/or chemical properties of soils and describe the role of each property in determining soil quality. (d) Describe TWO viable strategies for reducing the amount of land needed for agriculture. © 2011 The College Board. Visit the College Board on the Web: www.collegeboard.org. GO ON TO THE NEXT PAGE. -6- 2011 AP® ENVIRONMENTAL SCIENCE FREE-RESPONSE QUESTIONS (e) One problem that can result from agriculture is soil salinization. (i) Describe how salinization occurs. (ii) Describe one method to prevent or remediate soil salinization. STOP END OF EXAM © 2011 The College Board. Visit the College Board on the Web: www.collegeboard.org. -7- AP® Environmental Science 2010 Free-Response Questions The College Board The College Board is a not-for-profit membership association whose mission is to connect students to college success and opportunity. Founded in 1900, the College Board is composed of more than 5,700 schools, colleges, universities and other educational organizations. Each year, the College Board serves seven million students and their parents, 23,000 high schools, and 3,800 colleges through major programs and services in college readiness, college admission, guidance, assessment, financial aid and enrollment. Among its widely recognized programs are the SAT®, the PSAT/NMSQT®, the Advanced Placement Program® (AP®), SpringBoard® and ACCUPLACER®. The College Board is committed to the principles of excellence and equity, and that commitment is embodied in all of its programs, services, activities and concerns. © 2010 The College Board. College Board, ACCUPLACER, Advanced Placement Program, AP, AP Central, SAT, SpringBoard and the acorn logo are registered trademarks of the College Board. Admitted Class Evaluation Service is a trademark owned by the College Board. PSAT/NMSQT is a registered trademark of the College Board and National Merit Scholarship Corporation. All other products and services may be trademarks of their respective owners. Permission to use copyrighted College Board materials may be requested online at: www.collegeboard.com/inquiry/cbpermit.html. Visit the College Board on the Web: www.collegeboard.com. AP Central is the official online home for the AP Program: apcentral.collegeboard.com. 2010 AP® ENVIRONMENTAL SCIENCE FREE-RESPONSE QUESTIONS ENVIRONMENTAL SCIENCE SECTION II Time— 90 minutes 4 Questions Directions: Answer all four questions, which are weighted equally; the suggested time is about 22 minutes for answering each question. Write all your answers on the pages following the questions in the pink booklet. Where calculations are required, clearly show how you arrived at your answer. Where explanation or discussion is required, support your answers with relevant information and/or specific examples. 1. Read the following article from the Fremont Gazette and answer the questions that follow. (a) Choose any ONE of the three pollutants mentioned above and respond to each of the following. (i) Describe one specific source, other than the local chemical plants, for the toxic pollutant you chose. (ii) Describe how the pollutant you chose enters the human body and one specific effect it can have on human health. (iii) Describe TWO specific steps, other than an outright ban, that a city or nation can take to reduce the threat posed by this pollutant. © 2010 The College Board. Visit the College Board on the Web: www.collegeboard.com. GO ON TO THE NEXT PAGE. -2- 2010 AP® ENVIRONMENTAL SCIENCE FREE-RESPONSE QUESTIONS (b) Give one reason why Dr. Egguen is correct in asserting that children are particularly susceptible to toxic pollutants. (c) An important contributor to global climate change is the release of CO2 from the rapidly increasing number of coal-burning power plants in China. Assume that the coal burned at these plants to provide the power to manufacture a single MP3 player releases 40 kg of CO2 and that it costs $0.75 to capture 1 kg of CO2 and keep it from entering the atmosphere. Determine the cost, in dollars, to capture the total amount of CO2 released from manufacturing one MP3 player. (d) Coal-burning power plants also release other pollutants, including nitrogen oxides (NOx ), sulfur oxides (SOx ), and particulates. Select one of these pollutants and identify one technology that can be used to remove it from the waste stream of coal-burning power plants. (e) Discuss TWO reasons why a multinational company would choose to build a manufacturing facility in India and/or China rather than in the United States or Europe. © 2010 The College Board. Visit the College Board on the Web: www.collegeboard.com. GO ON TO THE NEXT PAGE. -3- 2010 AP® ENVIRONMENTAL SCIENCE FREE-RESPONSE QUESTIONS 2. Termites are social insects that are essential decomposers in tropical rain forest ecosystems. Termites may account for up to 95 percent of insect biomass in tropical rain forests. Termites consume vast amounts of dead and decomposing plant material, thanks to the work of mutualistic cellulose-digesting microorganisms that inhabit their guts. In addition to their roles as important decomposers, termites digest plant materials and directly contribute to carbon dioxide and methane emissions into the atmosphere. It is likely that, like many insect species, termites and their symbionts may be sensitive to changes in their microclimate caused by global climate change, especially with regard to temperature and humidity. Temperature Relative Humidity 50% 70% 90% 20°C 0.04 0.05 0.05 25°C 0.05 0.07 0.10 30°C 0.12 0.13 0.27 35°C 0.09 0.13 0.15 40°C 0.00 0.00 0.00 (a) Respond to the following using the data in the table above, which gives the rate of wood consumption by termites, in mg per day per termite, under various temperature and relative humidity conditions. Under optimal conditions, the emission rate of methane by termites is approximately 70 kilograms of CH4 per year per 1,000 termites. (i) According to the data, what are the optimal temperature and relative humidity for termite activity? (ii) Given a density of 4.5 × 107 termites per hectare and optimal conditions, calculate the annual amount of methane emitted, in kilograms, by the termites inhabiting a 2,000-hectare tropical rain forest. (iii) Suppose the temperature increases to 35°C and the relative humidity decreases to 50 percent. Using the data provided, determine the amount of methane, in kilograms, that would be emitted by the termites in the 2,000-hectare tropical rain forest. (iv) Explain why the population size of termites is also affected by temperature and humidity. (b) It has been observed that soon after a tropical rain forest is cleared, termite density increases to an estimated 6.8 × 107 termites per hectare. Thereafter, the termite population size decreases dramatically. (i) What is the most likely reason that the density of the termites increases when a tropical rain forest is cleared? (ii) Why do the termite populations eventually decrease dramatically? (c) Describe one way, other than changes in termite activity, that tropical rain forest destruction contributes to anthropogenic climate change. © 2010 The College Board. Visit the College Board on the Web: www.collegeboard.com. GO ON TO THE NEXT PAGE. -4- 2010 AP® ENVIRONMENTAL SCIENCE FREE-RESPONSE QUESTIONS 3. The zebra mussel, a mollusk native to Eurasia, was first discovered in the Great Lakes of North America in 1988. Zebra mussels attach to solid substrates and are filter feeders. Adult zebra mussels can survive for several days or even weeks out of water if the temperature and humidity are favorable. An adult female zebra mussel can produce as many as one million eggs per year. The recent range of occurrence of zebra mussels in the United States is indicated by shading in the map above. (a) Why are zebra mussels located primarily in areas in the eastern United States rather than in the western United States? (b) How are zebra mussels introduced into isolated lakes? Describe one viable method for preventing the spread of zebra mussels into isolated lakes. (c) Identify and explain one impact that zebra mussels can have on aquatic ecosystems. (d) Identify another invasive species, either terrestrial or aquatic, and describe one negative impact it has had. (e) One strategy for controlling an invasive species has been to introduce another nonnative species to control it; this strategy can often have unintended results. Give a specific example of the use of this strategy and discuss a negative impact of introducing a nonnative species to control an invasive species. (f) Discuss TWO specific characteristics of invasive species that enable them to thrive in new environments. © 2010 The College Board. Visit the College Board on the Web: www.collegeboard.com. GO ON TO THE NEXT PAGE. -5- 2010 AP® ENVIRONMENTAL SCIENCE FREE-RESPONSE QUESTIONS 4. Scientific evidence shows a direct relationship between sea level and the global mean atmospheric temperature at Earth’s surface. Increases in the global mean atmospheric temperature during the past century have been accompanied by a gradual increase in sea level; currently the average rate of increase in sea level is 3.0 mm/yr. Additional increases in sea level are expected during the next century as global mean atmospheric temperatures continue to rise. These increases in sea level will affect coastal ecosystems as well as human activity along coastal margins. (a) Based on the rate cited above, calculate the expected increase in sea level, in meters, during the next 50 years. (b) Identify TWO phenomena that result from an increase in global mean atmospheric temperature and that contribute to increases in sea level. For each phenomenon that you identify, explain how it causes sea level to increase. (c) Describe TWO environmental impacts that increasing sea level will have on an estuarine ecosystem such as those in the Mississippi Delta, Chesapeake Bay, and San Francisco Bay. (d) Although sea level has been rising for over a century, human populations in coastal areas have increased dramatically during this period. (i) Describe one negative economic impact that an increase in sea level will have on people who live along a coastline. (ii) Describe TWO viable strategies that governments could use to discourage people from moving to coastal areas. STOP END OF EXAM © 2010 The College Board. Visit the College Board on the Web: www.collegeboard.com. -6- AP® Environmental Science 2009 Free-Response Questions The College Board The College Board is a not-for-profit membership association whose mission is to connect students to college success and opportunity. Founded in 1900, the association is composed of more than 5,600 schools, colleges, universities and other educational organizations. Each year, the College Board serves seven million students and their parents, 23,000 high schools and 3,800 colleges through major programs and services in college readiness, college admissions, guidance, assessment, financial aid, enrollment, and teaching and learning. Among its best-known programs are the SAT®, the PSAT/NMSQT® and the Advanced Placement Program® (AP®). The College Board is committed to the principles of excellence and equity, and that commitment is embodied in all of its programs, services, activities and concerns. © 2009 The College Board. All rights reserved. College Board, Advanced Placement Program, AP, AP Central, SAT, and the acorn logo are registered trademarks of the College Board. PSAT/NMSQT is a registered trademark of the College Board and National Merit Scholarship Corporation. Permission to use copyrighted College Board materials may be requested online at: www.collegeboard.com/inquiry/cbpermit.html. Visit the College Board on the Web: www.collegeboard.com. AP Central is the official online home for the AP Program: apcentral.collegeboard.com. 2009 AP® ENVIRONMENTAL SCIENCE FREE-RESPONSE QUESTIONS ENVIRONMENTAL SCIENCE SECTION II Time— 90 minutes 4 Questions Directions: Answer all four questions, which are weighted equally; the suggested time is about 22 minutes for answering each question. Write all your answers on the pages following the questions in the pink booklet. Where calculations are required, clearly show how you arrived at your answer. Where explanation or discussion is required, support your answers with relevant information and/or specific examples. 1. Read the article below from the Fremont Free Press and answer the questions that follow. (a) Support Councilwoman Smith’s statement that nitrogen-based fertilizers cause other environmental problems by describing one such problem. (b) Identify a nitrogen-containing primary pollutant that contributes to the formation of photochemical smog. Describe how that primary pollutant forms and explain why Councilman Budd was wrong. (c) Identify one secondary pollutant that is a component of photochemical smog and describe the following. (i) How the secondary pollutant forms (ii) ONE human health effect of the pollutant (iii) ONE environmental effect of the pollutant (d) Earth’s natural nitrogen cycle occurs in several steps. Describe one chemical transformation that occurs in the natural nitrogen cycle and discuss the importance of that transformation to an ecosystem. © 2009 The College Board. All rights reserved. Visit the College Board on the Web: www.collegeboard.com. GO ON TO THE NEXT PAGE. -2- 2009 AP® ENVIRONMENTAL SCIENCE FREE-RESPONSE QUESTIONS 2. Anaerobic methane digesters have been used for many years to reduce energy costs on farms throughout Europe and on some large farms in the United States. The digesters operate by using anaerobic bacteria to break down animal waste. During the process, which typically uses a tank heated to about 100°F (38ÁC) to speed the reactions, raw manure is broken down and methane is produced. The methane can then be used to generate electricity or produce heat. For a certain dairy farm with 500 cows, the cost of installing a digester is approximately $400,000. Assume that the farm uses 800,000 kilowatt-hours (kWh) of electricity each year at a cost of $0.10 per kWh. The waste from a single cow can produce 3.0 kWh of electricity each day. (a) Describe the steps by which methane produced in the digester can be used to generate electricity. (b) Discuss TWO environmental benefits that may result from the installation of an anaerobic methane digester. (c) Assuming that the cost of electricity remains constant and the farmer starts using the manure from the cows in an anaerobic digester to produce electricity on the farm, calculate: (i) The number of kWh of electricity that can be produced in one year (ii) The amount of money the farmer can save in one year, NOT counting the installation cost of the digester. (You may round your answer to the nearest $1,000.) (iii) The amount of time, in years, that it will take to recover the cost of installing an anaerobic digester on the farm. (You may round your answer to the nearest whole number of years.) (d) Calculate the minimum number of cows the farm would need to produce 800,000 kWh of electricity per year. 3. The Colorado River flows from the Colorado Rockies to the Gulf of California. The primary source of Colorado River water is melting Rocky Mountain snowpack. Once the river descends from the Rockies, it flows through a landscape that is dominated by desert. Colorado River water carries a high load of sediment. (a) Multiple dams have been erected along the Colorado River. Identify TWO benefits other than agriculture and recreation that people derive from that system of dams. (b) Discuss TWO potential environmental consequences of damming a major river. (c) Competition for access to Colorado River water has increased dramatically due to increased population size and intensive agricultural use. Describe TWO conservation strategies for reducing agricultural water consumption. (d) Identify TWO possible environmental consequences of climate change on the hydrology of the Colorado River system. (e) In addition to impacts on the Colorado River system, climate change is impacting the hydrology of coastal ecosystems. Identify and describe TWO possible consequences of climate change on coastal ecosystems. © 2009 The College Board. All rights reserved. Visit the College Board on the Web: www.collegeboard.com. GO ON TO THE NEXT PAGE. -3- 2009 AP® ENVIRONMENTAL SCIENCE FREE-RESPONSE QUESTIONS 4. The major issues in modern agriculture include the use of genetically modified (GM) crops and the implementation of sustainable agricultural practices. The following graph shows the increase in the use of GM crops in both developing and industrialized countries from 1995 to 2004. (a) Reply to the following questions based on the data in the graph above. (i) Calculate the increase in the area of land used for growing GM crops in developing countries from 1999 to 2003. Express your answer as a percentage of the 1999 value. (ii) Calculate the annual rate of increase in land area used for growing GM crops in industrialized countries from 1997 to 1999. (iii) Using the rate you calculated in part (ii), project the area of land that would have been expected to be used for GM crops in industrialized countries in 2004. (iv) Identify one likely cause for the difference between the projected land area for GM crops in industrialized countries in 2004 and the actual land area for GM crops in industrialized countries in 2004. © 2009 The College Board. All rights reserved. Visit the College Board on the Web: www.collegeboard.com. GO ON TO THE NEXT PAGE. -4- 2009 AP® ENVIRONMENTAL SCIENCE FREE-RESPONSE QUESTIONS (b) Describe one environmental advantage and one environmental disadvantage of using GM crops. (c) Describe one economic advantage and one economic disadvantage of using GM crops. (d) A healthy soil ecosystem is of primary importance in sustainable agriculture. Describe TWO viable agricultural practices that farmers can use to maintain or improve soil quality. (e) Identify and describe one environmental advantage and one economic advantage of consuming locally grown produce. STOP END OF EXAM © 2009 The College Board. All rights reserved. Visit the College Board on the Web: www.collegeboard.com. -5- AP® Environmental Science 2008 Free-Response Questions The College Board: Connecting Students to College Success The College Board is a not-for-profit membership association whose mission is to connect students to college success and opportunity. Founded in 1900, the association is composed of more than 5,000 schools, colleges, universities, and other educational organizations. Each year, the College Board serves seven million students and their parents, 23,000 high schools, and 3,500 colleges through major programs and services in college admissions, guidance, assessment, financial aid, enrollment, and teaching and learning. Among its best-known programs are the SAT®, the PSAT/NMSQT®, and the Advanced Placement Program® (AP®). The College Board is committed to the principles of excellence and equity, and that commitment is embodied in all of its programs, services, activities, and concerns. © 2008 The College Board. All rights reserved. College Board, Advanced Placement Program, AP, AP Central, SAT, and the acorn logo are registered trademarks of the College Board. PSAT/NMSQT is a registered trademark of the College Board and National Merit Scholarship Corporation. Permission to use copyrighted College Board materials may be requested online at: www.collegeboard.com/inquiry/cbpermit.html. Visit the College Board on the Web: www.collegeboard.com. AP Central is the official online home for the AP Program: apcentral.collegeboard.com. 2008 AP® ENVIRONMENTAL SCIENCE FREE-RESPONSE QUESTIONS ENVIRONMENTAL SCIENCE SECTION II Time— 90 minutes 4 Questions Directions: Answer all four questions, which are weighted equally; the suggested time is about 22 minutes for answering each question. Write all your answers on the pages following the questions in the pink booklet. Where calculations are required, clearly show how you arrived at your answer. Where explanation or discussion is required, support your answers with relevant information and/or specific examples. 1. Read the article below and answer the questions that follow. © 2008 The College Board. All rights reserved. Visit apcentral.collegeboard.com (for AP professionals) and www.collegeboard.com/apstudents (for students and parents). GO ON TO THE NEXT PAGE. -2- 2008 AP® ENVIRONMENTAL SCIENCE FREE-RESPONSE QUESTIONS (a) Calculate the number of acres required to produce 1,000 gallons of oil in one year from (i) microalgae (ii) soybeans (b) Describe TWO environmental advantages that biodiesel production from microalgae offers over biodiesel production from the other crops listed in the table. (c) Explain why burning biodiesel fuel has a different impact on atmospheric CO2 concentrations than does burning fossil fuels. (d) Discuss TWO benefits, other than those related to atmospheric impacts, of increased reliance on biodiesel fuels over the next 50 years. (e) Describe TWO economic or societal problems associated with producing fuel from corn. © 2008 The College Board. All rights reserved. Visit apcentral.collegeboard.com (for AP professionals) and www.collegeboard.com/apstudents (for students and parents). GO ON TO THE NEXT PAGE. -3- 2008 AP® ENVIRONMENTAL SCIENCE FREE-RESPONSE QUESTIONS 2. The city of Fremont operates a municipal solid-waste landfill. As represented in the diagram above, the annual precipitation in Fremont is 200 mm/year: 50 percent of this water infiltrates through the landfill cover soil into the waste, and 50 percent drains off the landfill. A drainage system withdraws 90 percent of the leachate generated within the landfill for treatment. The rest of the leachate travels through the bottom liner of the landfill into the surrounding soil. Most of the cadmium disposed of in the landfill remains in the landfill; the leachate withdrawn from the landfill by the drainage system has an average cadmium concentration of 2.0 g/m3. Pumped to a treatment station, the leachate is treated at a cost of $10/m3. (a) Calculate the volume, in m3, of each of the following: (i) The water infiltrated through the landfill per year (ii) The leachate that is treated per year (b) Given that the cadmium concentration in the water draining from the landfill is 2.0 g/m3, calculate the mass, in kg, of cadmium that is released into the surrounding soil per year. (c) What is the annual cost of treating the leachate from the drainage system? (d) Discuss TWO viable methods for reducing the amount of cadmium entering the municipal waste input. (e) Explain a shortcoming of ONE of the methods that you identified in part (d). © 2008 The College Board. All rights reserved. Visit apcentral.collegeboard.com (for AP professionals) and www.collegeboard.com/apstudents (for students and parents). GO ON TO THE NEXT PAGE. -4- 2008 AP® ENVIRONMENTAL SCIENCE FREE-RESPONSE QUESTIONS 3. For decades, forest fires in the United States have been suppressed. In 2003 legislation was passed under the Healthy Forests Initiative (HFI) in response to the record-breaking wildfires that had occurred in the early 2000s. Some environmental and conservation groups fear that negative impacts could result if timber companies are encouraged to harvest medium- and large-size trees in federally owned forests while clearing away the smaller trees and underbrush. (a) Identify TWO characteristics of forests that develop when fires are suppressed, and explain why the practice of fire suppression does not reduce, but actually increases, the risk of intense and extensive forest fires. (b) The effects of the HFI are expected to extend beyond fire reduction. Excluding fire reduction, describe ONE positive and ONE negative effect likely to result from the implementation of the provisions of the HFI. (c) Describe TWO ecosystem services provided for humans by forests. Explain how clear-cutting would affect each ecosystem service you describe. (d) Identify a specific type of plant community or biome (other than a forest) that is naturally maintained by fire. Explain how the fire maintains the community or biome. © 2008 The College Board. All rights reserved. Visit apcentral.collegeboard.com (for AP professionals) and www.collegeboard.com/apstudents (for students and parents). GO ON TO THE NEXT PAGE. -5- 2008 AP® ENVIRONMENTAL SCIENCE FREE-RESPONSE QUESTIONS 4. Answer the following regarding world human population. (a) Create a graph of the data from table 1 below on the axes provided. Table 1: Worldwide Total Fertility Rate (TFR) Year TFR 1950 5.0 1960 4.9 1970 4.7 1980 3.7 1990 3.4 2000 3.0 (b) Identify and discuss TWO of the causes for the trend in the worldwide TFR that you graphed in part (a). © 2008 The College Board. All rights reserved. Visit apcentral.collegeboard.com (for AP professionals) and www.collegeboard.com/apstudents (for students and parents). GO ON TO THE NEXT PAGE. -6- 2008 AP® ENVIRONMENTAL SCIENCE FREE-RESPONSE QUESTIONS Table 2: Population Data for Selected Nations (2005) Country TFR Crude Birth Rate* Crude Death Rate* Infant Mortality Rate* (U.S. dollars) Per Capita Income China 1.6 12 7 27 6,500 Japan 1.3 9 8 2.8 31,400 Kenya 5.9 43 19 100 1,000 United States 2.0 14 8 6.7 42,000 * rates are per thousand per year (c) Consider the data in table 2 above. Identify and discuss TWO economic or societal factors that account for the difference between the TFR of Kenya and that of the United States. (d) Describe TWO human activities related to the rapidly growing world population that are having an impact on Earth’s biodiversity. STOP END OF EXAM © 2008 The College Board. All rights reserved. Visit apcentral.collegeboard.com (for AP professionals) and www.collegeboard.com/apstudents (for students and parents). -7- AP® Environmental Science 2007 Free-Response Questions The College Board: Connecting Students to College Success The College Board is a not-for-profit membership association whose mission is to connect students to college success and opportunity. Founded in 1900, the association is composed of more than 5,000 schools, colleges, universities, and other educational organizations. Each year, the College Board serves seven million students and their parents, 23,000 high schools, and 3,500 colleges through major programs and services in college admissions, guidance, assessment, financial aid, enrollment, and teaching and learning. Among its best-known programs are the SAT®, the PSAT/NMSQT®, and the Advanced Placement Program® (AP®). The College Board is committed to the principles of excellence and equity, and that commitment is embodied in all of its programs, services, activities, and concerns. © 2007 The College Board. All rights reserved. College Board, Advanced Placement Program, AP, AP Central, SAT, and the acorn logo are registered trademarks of the College Board. PSAT/NMSQT is a registered trademark of the College Board and National Merit Scholarship Corporation. Permission to use copyrighted College Board materials may be requested online at: www.collegeboard.com/inquiry/cbpermit.html. Visit the College Board on the Web: www.collegeboard.com. AP Central is the official online home for the AP Program: apcentral.collegeboard.com. 2007 AP® ENVIRONMENTAL SCIENCE FREE-RESPONSE QUESTIONS ENVIRONMENTAL SCIENCE SECTION II Time—90 minutes 4 Questions Directions: Answer all four questions, which are weighted equally; the suggested time is about 22 minutes for answering each question. Write all your answers on the pages following the questions in the pink booklet. Where calculations are required, clearly show how you arrived at your answer. Where explanation or discussion is required, support your answers with relevant information and/or specific examples. 1. Read the Fremont Examiner article below and answer the questions that follow. (a) Identify ONE component of the sewage that is targeted for removal by primary treatment and ONE component of the sewage that is targeted for removal by secondary treatment. (b) For EACH of the pollutants that you identified in part (a), describe how the pollutant is removed in the treatment process. (c) Explain how sewage treatment plants create the solid waste problem that Dr. Goodwin mentioned in the article. (d) Two common methods of disposing of solid waste from sewage treatment plants are transporting it to a landfill or spreading it onto agricultural lands. Describe an environmental problem associated with EACH of these methods. (e) The final step in sewage treatment is disinfection. Identify ONE pollutant that is targeted during disinfection and identify ONE commonly used method of disinfection. (f) Identify ONE United States federal law that requires monitoring the quality of the treated sewage that is discharged into the Fremont River. © 2007 The College Board. All rights reserved. Visit apcentral.collegeboard.com (for AP professionals) and www.collegeboard.com/apstudents (for students and parents). GO ON TO THE NEXT PAGE. -2- 2007 AP® ENVIRONMENTAL SCIENCE FREE-RESPONSE QUESTIONS 2. The Cobb family of Fremont is looking at ways to decrease their home water and energy usage. Their current electric hot-water heater raises the water temperature to 140°F, which requires 0.20 kWh/gallon at a cost of $0.10/kWh. Each person in the family of four showers once a day for an average of 10 minutes per shower. The shower has a flow rate of 5.0 gallons per minute. (a) Calculate the following. Be sure to show all your work and include units with your answers. (i) The total amount of water that the family uses per year for taking showers (ii) The annual cost of the electricity for the family showers, assuming that 2.5 gallons per minute of the water used is from the hot-water heater (b) The family is considering replacing their current hot-water heater with a new energy-efficient hot-water heater that costs $1,000 and uses half the energy that their current hot-water heater uses. How many days would it take for the new hot-water heater to recover the $1,000 initial cost? (c) Describe TWO practical measures that the family could take that would reduce their overall water use at home. (d) Describe TWO conservation measures (other than reducing hot water use) that the family could take to reduce the total amount of energy that they use at home. 3. In the mid 1970s, Sherwood Rowland and Mario Molina predicted a thinning of the stratospheric ozone layer over Antarctica. The thinning was confirmed in the late twentieth century and has continued into the twenty-first century. (a) Identify the class of chemical compounds that is primarily responsible for the thinning of the stratospheric ozone layer and describe TWO major uses for which these chemicals were manufactured. (b) Describe how the chemical compounds that you identified in part (a) destroy stratospheric ozone molecules. You may include chemical equations as part of your answer. (c) Identify the major environmental consequence of the depletion of stratospheric ozone and describe TWO effects on ecosystems and/or human health that can result. (d) Ozone formed at ground level is a harmful pollutant. Describe TWO effects that ground-level ozone can have on ecosystems and/or human health. © 2007 The College Board. All rights reserved. Visit apcentral.collegeboard.com (for AP professionals) and www.collegeboard.com/apstudents (for students and parents). GO ON TO THE NEXT PAGE. -3- 2007 AP® ENVIRONMENTAL SCIENCE FREE-RESPONSE QUESTIONS 4. Some scientists estimate that by 2025 over 60 percent of the global human population will live in urban areas. Urban residents experience a variety of problems related to the physical environment. (a) Describe how the temperature of urban areas like Atlanta, Philadelphia, and Chicago differs from that of surrounding rural areas. (b) Identify and describe TWO differences between urban and surrounding rural areas that contribute to the temperature difference between them. (c) Urban areas typically have levels of air pollution that are significantly higher than those found in surrounding rural areas. Identify a characteristic of the urban microclimate that leads to higher levels of air pollution and describe how that characteristic contributes to the increase. (d) Identify and describe TWO actions that local governments in urban areas could take to reduce outdoor air pollution. (e) Identify and describe TWO ways in which the local hydrologic cycle of urban areas differs from that of nearby rural areas. STOP END OF EXAM © 2007 The College Board. All rights reserved. Visit apcentral.collegeboard.com (for AP professionals) and www.collegeboard.com/apstudents (for students and parents). -4- AP® Environmental Science 2006 Free-Response Questions The College Board: Connecting Students to College Success The College Board is a not-for-profit membership association whose mission is to connect students to college success and opportunity. Founded in 1900, the association is composed of more than 5,000 schools, colleges, universities, and other educational organizations. Each year, the College Board serves seven million students and their parents, 23,000 high schools, and 3,500 colleges through major programs and services in college admissions, guidance, assessment, financial aid, enrollment, and teaching and learning. Among its best-known programs are the SAT®, the PSAT/NMSQT®, and the Advanced Placement Program® (AP®). The College Board is committed to the principles of excellence and equity, and that commitment is embodied in all of its programs, services, activities, and concerns. © 2006 The College Board. All rights reserved. College Board, AP Central, APCD, Advanced Placement Program, AP, AP Vertical Teams, Pre-AP, SAT, and the acorn logo are registered trademarks of the College Board. Admitted Class Evaluation Service, CollegeEd, connect to college success, MyRoad, SAT Professional Development, SAT Readiness Program, and Setting the Cornerstones are trademarks owned by the College Board. PSAT/NMSQT is a registered trademark of the College Board and National Merit Scholarship Corporation. All other products and services may be trademarks of their respective owners. Permission to use copyrighted College Board materials may be requested online at: www.collegeboard.com/inquiry/cbpermit.html. Visit the College Board on the Web: www.collegeboard.com. AP Central is the official online home for the AP Program: apcentral.collegeboard.com. 2006 AP® ENVIRONMENTAL SCIENCE FREE-RESPONSE QUESTIONS ENVIRONMENTAL SCIENCE SECTION II Time—90 minutes 4 Questions Directions: Answer all four questions, which are weighted equally; the suggested time is about 22 minutes for answering each question. Write all your answers on the pages following the questions in the pink booklet. Where calculations are required, clearly show how you arrived at your answer. Where explanation or discussion is required, support your answers with relevant information and/or specific examples. 1. Upon receiving notice from their electric utility that customers with solar power systems are permitted to sell excess power back to the utility, an Arizona family is considering the purchase of a photovoltaic solar energy system for their 2,700-square-foot suburban home. The initial costs of the systems they are considering range from $7,000 to $30,000. While gathering information prior to making a decision, the homeowners find the following information at the Web site of the United States Department of Energy. Stand-Alone vs. Grid-Connected Systems Stand-alone systems produce power independently of the utility grid. In some off-the-grid locations as near as one-quarter mile from the power lines, stand-alone photovoltaic systems can be more costeffective than extending power lines. Direct-coupled systems need no electrical storage because they operate only during daylight hours, but most systems rely on battery storage so that energy produced during the day can be used at night. Some systems, called hybrid systems, combine solar power with additional power sources such as wind or diesel. Grid-connected photovoltaic systems supply surplus power back through the grid to the utility and take from the utility grid when the home system’s power supply is low. These systems remove the need for battery storage, although arranging for the grid interconnection can be difficult. In some cases, utilities allow net metering, which allows the owner to sell excess power back to the utility. (a) Describe one environmental benefit and one environmental cost of photovoltaic systems. (b) From the two types of solar systems described on the government Web site, select the system (either standalone or grid-connected) that you think best meets the needs of the homeowners. Write an argument to persuade them to purchase the system you selected. Include the pros and cons of each system in your argument. (c) Describe TWO ways that government or industry could promote the use of photovoltaic power systems for homeowners in the future. (d) Describe TWO ways that homeowners could use passive solar designs and/or systems and, for each way, explain how it would reduce the homeowners’ energy costs. © 2006 The College Board. All rights reserved. Visit apcentral.collegeboard.com (for AP professionals) and www.collegeboard.com/apstudents (for students and parents). GO ON TO THE NEXT PAGE. 2 2006 AP® ENVIRONMENTAL SCIENCE FREE-RESPONSE QUESTIONS 2. According to atmospheric temperature and CO2 concentration records derived from Antarctic ice cores, Earth’s climate has undergone significant changes over the past 200,000 years. Two graphs are shown below. The upper graph shows the variation in atmospheric CO2 concentration, and the lower graph shows the variation in air temperature. Both graphs cover the same time period from approximately 200,000 years ago up until the year 1950, which is represented as year 0 on the graphs. (a) Answer the following questions that relate to the graphs above. Remember that for any calculations you must clearly indicate how you arrived at your answer. Answers must also include appropriate units. (i) Determine the net change in atmospheric CO2 concentration between 140,000 years ago and 125,000 years ago. (ii) Calculate the ratio of the change in mean global temperature to the change in atmospheric CO2 concentration between 140,000 years ago and 125,000 years ago. (iii) Scientists predict that between 1950 and 2050, the atmospheric CO2 concentration will increase by 200 ppm. Predict the change in mean global temperature between 1950 and 2050 using the ratio that you calculated in part (ii). (iv) Describe one major assumption that was necessary to make the prediction in part (iii) above. Discuss the validity of the assumption. © 2006 The College Board. All rights reserved. Visit apcentral.collegeboard.com (for AP professionals) and www.collegeboard.com/apstudents (for students and parents). GO ON TO THE NEXT PAGE. 3 2006 AP® ENVIRONMENTAL SCIENCE FREE-RESPONSE QUESTIONS (b) Identify and describe TWO major causes for the predicted 200 ppm increase in atmospheric CO2 concentration between 1950 and 2050. (c) Identify TWO gases other than CO2 that contribute to the anthropogenic increase in mean global temperature. For each gas, describe a major human activity that leads to its release. 3. The city of Fremont has a large brownfield located along the Fremont River. The brownfield is a former industrial site where contamination by hazardous chemicals impedes redevelopment. The city council is considering two options for reclaiming the brownfield. The first option is to excavate and remove the contaminated soil, and the second option is to decontaminate the soil on the site using vegetation. (a) Assume that the city council chooses the first option. Describe TWO problems that result from removing the contaminated soil from the brownfield. (b) Assume that the city council chooses the second option. Explain how vegetation could be used to decontaminate the soil. Discuss one advantage and one disadvantage of using this reclamation method. (c) Describe and explain one environmental benefit and one societal benefit of brownfield reclamation. (d) Identify and describe (i) one method currently used to reduce the production of hazardous waste and (ii) one method of legally disposing of hazardous waste. © 2006 The College Board. All rights reserved. Visit apcentral.collegeboard.com (for AP professionals) and www.collegeboard.com/apstudents (for students and parents). GO ON TO THE NEXT PAGE. 4 2006 AP® ENVIRONMENTAL SCIENCE FREE-RESPONSE QUESTIONS 4. The graph above shows the decline in the catch of groundfish (such as cod, haddock, and flounder) from Georges Bank from 1965 to 1995. This decline in the fish harvest resulted in the closure of large portions of the fishery. (a) Identify the five-year period during which the greatest rate of decline in the fish harvest took place. For that five-year period, calculate the rate of decline in the fish harvest, in metric tons per year. Show clearly how you determined your answer. (b) Choose any TWO commercial fishing practices from the list below. For each of your choices, describe the practice and explain the role it plays in the depletion of marine organisms. • Bottom trawling • Long-line fishing • Using drift nets/gill nets/purse seines • Using sonar (c) Identify one international regulation or United States federal law that applies to the harvesting of marine food resources and explain how that regulation or law helps to manage marine species. (d) The oceans of the world are often referred to as a commons. Give an example of one other such commons, explain how human activities affect that commons, and suggest one practical method for managing that commons. STOP END OF EXAM © 2006 The College Board. All rights reserved. Visit apcentral.collegeboard.com (for AP professionals) and www.collegeboard.com/apstudents (for students and parents). 5 AP® Environmental Science 2005 Free-Response Questions The College Board: Connecting Students to College Success The College Board is a not-for-profit membership association whose mission is to connect students to college success and opportunity. Founded in 1900, the association is composed of more than 4,700 schools, colleges, universities, and other educational organizations. Each year, the College Board serves over three and a half million students and their parents, 23,000 high schools, and 3,500 colleges through major programs and services in college admissions, guidance, assessment, financial aid, enrollment, and teaching and learning. Among its best-known programs are the SAT®, the PSAT/NMSQT®, and the Advanced Placement Program® (AP®). 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Visit the College Board on the Web: www.collegeboard.com. AP Central is the official online home for the AP Program and Pre-AP: apcentral.collegeboard.com. 2005 AP® ENVIRONMENTAL SCIENCE FREE-RESPONSE QUESTIONS ENVIRONMENTAL SCIENCE SECTION II Time—90 minutes 4 Questions Directions: Answer all four questions, which are weighted equally; the suggested time is about 22 minutes for answering each question. Write all your answers on the pages following the questions in this booklet. Where calculations are required, clearly show how you arrived at your answer. Where explanation or discussion is required, support your answers with relevant information and/or specific examples. 1. Read the following article from the Fremont Examiner. (a) For one new disease and one old disease named in the article above, explain how the disease is transmitted through the human population and describe an effective method for controlling the spread of the disease. (b) For one of the two diseases you chose in part (a), identify one environmental factor that contributed to the emergence or reemergence of the disease and explain how that factor influenced the increased incidence of the disease. (c) Provide a rationale to support Dr. Amodie’s statement as quoted in the article. Copyright © 2005 by College Entrance Examination Board. All rights reserved. Visit apcentral.collegeboard.com (for AP professionals) and www.collegeboard.com/apstudents (for AP students and parents). GO ON TO THE NEXT PAGE. 2 2005 AP® ENVIRONMENTAL SCIENCE FREE-RESPONSE QUESTIONS (d) The graphs above show the mortality from infectious diseases in the United States since 1900. Identify an infectious disease that made an important contribution to the trend of increasing mortality rates that began in about 1980 and explain one major cause of the increased rate of mortality from that disease. 2. Between 1950 and 2000, global meat production increased from 52 billion kilograms to 240 billion kilograms. During this period, the global human population increased from 2.6 billion to 6.0 billion. (a) Calculate the per capita meat production in 1950 and in 2000. (b) Use the values from part (a) to calculate the change in global per capita meat production during this 50-year period as a percentage of the 1950 value. (c) Discuss why it is more efficient to produce grain for human consumption than to produce meat for human consumption. In your answer, consider both land use and energy use. (d) Describe TWO environmental consequences of the increase in the production of meat for human consumption. (e) Identify and explain one potential advantage and one potential disadvantage for human health of a diet that contains very little meat. Copyright © 2005 by College Entrance Examination Board. All rights reserved. Visit apcentral.collegeboard.com (for AP professionals) and www.collegeboard.com/apstudents (for AP students and parents). GO ON TO THE NEXT PAGE. 3 2005 AP® ENVIRONMENTAL SCIENCE FREE-RESPONSE QUESTIONS 3. Most of the coal mined in the United States today comes from surface (strip) mines. In surface mining, the vegetation, soil, and rock covering the coal (referred to as overburden) are removed and set aside. After the coal has been hauled away, good conservation practices require that the overburden be replaced and the surface be restored to its original condition. Land restoration may be difficult in some regions, due to factors such as the local climate, the thickness of the coal seam, the extent of the overburden, and the sulfur content of the coal. (a) Describe the steps that should be taken to restore the land after the overburden has been replaced. (b) Explain why the restoration of the land would likely be more difficult in an arid climate (less than ten inches of precipitation per year). (c) Describe one environmental impact that the sulfur content of the remaining coal and the tailings would have on the reclamation process and suggest a possible remedy. (d) Other than mining and reclamation, describe TWO environmental impacts of using coal for energy. (e) Explain why per capita coal consumption in the United States is likely to increase. 4. The Alaskan National Wildlife Refuge (ANWR) on Alaska’s North Slope is frequently in the news because petroleum geologists estimate that there are billions of barrels of economically recoverable oil beneath the surface of its frozen tundra. According to a 1998 United States Geological Survey (USGS) estimate, ANWR could contain up to 10 billion barrels of technically recoverable oil. Oil company officials advocate opening the refuge to oil exploration and the subsequent development of its petroleum resources. Environmentalists argue that oil exploration and development will damage this fragile ecosystem and urge Congress to protect ANWR by designating it as a wilderness area. (a) The United States consumes approximately 20 million barrels of oil per day. According to the USGS estimate, for how many days would the technically recoverable oil resource in ANWR supply the total United States demand for oil? (b) Describe TWO characteristics of arctic tundra that make it fragile and explain how these two characteristics make the tundra particularly susceptible to damage from human impacts. (c) Identify TWO activities that would be associated with the development of ANWR petroleum resources and describe a substantial environmental impact of each in ANWR. (d) Identify and describe TWO major end uses of the 20 million barrels of oil that the United States consumes each day and for each use describe a conservation measure that would substantially reduce United States consumption. END OF EXAM Copyright © 2005 by College Entrance Examination Board. All rights reserved. Visit apcentral.collegeboard.com (for AP professionals) and www.collegeboard.com/apstudents (for AP students and parents). 4 AP® Environmental Science 2004 Free-Response Questions The materials included in these files are intended for noncommercial use by AP teachers for course and exam preparation; permission for any other use ® must be sought from the Advanced Placement Program . Teachers may reproduce them, in whole or in part, in limited quantities, for face-to-face teaching purposes but may not mass distribute the materials, electronically or otherwise. This permission does not apply to any third-party copyrights contained herein. These materials and any copies made of them may not be resold, and the copyright notices must be retained as they appear here. The College Board is a not-for-profit membership association whose mission is to connect students to college success and opportunity. Founded in 1900, the association is composed of more than 4,500 schools, colleges, universities, and other educational organizations. Each year, the College Board serves over three million students and their parents, 23,000 high schools, and 3,500 colleges through major programs and services in college admissions, guidance, assessment, financial aid, enrollment, and teaching and learning. Among its best-known programs are the SAT®, the PSAT/NMSQT®, and the Advanced Placement Program® (AP®). The College Board is committed to the principles of excellence and equity, and that commitment is embodied in all of its programs, services, activities, and concerns. For further information, visit www.collegeboard.com Copyright © 2004 College Entrance Examination Board. All rights reserved. College Board, Advanced Placement Program, AP, AP Central, AP Vertical Teams, APCD, Pacesetter, Pre-AP, SAT, Student Search Service, and the acorn logo are registered trademarks of the College Entrance Examination Board. PSAT/NMSQT is a registered trademark jointly owned by the College Entrance Examination Board and the National Merit Scholarship Corporation. Educational Testing Service and ETS are registered trademarks of Educational Testing Service. Other products and services may be trademarks of their respective owners. For the College Board’s online home for AP professionals, visit AP Central at apcentral.collegeboard.com. 2004 AP® ENVIRONMENTAL SCIENCE FREE-RESPONSE QUESTIONS ENVIRONMENTAL SCIENCE SECTION II Time—90 minutes 4 Questions Directions: Answer all four questions, which are weighted equally; the suggested time is about 22 minutes for answering each question. Write all your answers on the pages following the questions in the pink booklet. Where calculations are required, clearly show how you arrived at your answer. Where explanation or discussion is required, support your answers with relevant information and/or specific examples. 1. Read the editorial below and answer the questions that follow. (a) On the basis of the article above, indicate one human activity that releases mercury into the environment. Describe how mercury is transported from that source and enters aquatic systems, often hundreds of miles away. (b) Describe TWO ways that the amount of mercury released into the environment from the source in part (a) could be reduced. (c) Explain why there are greater health risks associated with eating large predatory fish, such as tuna and sea bass, than from eating small nonpredatory fish. (d) Identify a toxic metal other than mercury that has a negative impact on human health and describe how it is introduced into the environment. Describe an acute sublethal effect on humans that results from exposure to this metal. Copyright © 2004 by College Entrance Examination Board. All rights reserved. Visit apcentral.collegeboard.com (for AP professionals) and www.collegeboard.com/apstudents (for AP students and parents). GO ON TO THE NEXT PAGE. 2 2004 AP® ENVIRONMENTAL SCIENCE FREE-RESPONSE QUESTIONS 2. West Fremont is a community consisting of 3,000 homes. A small coal-burning power plant currently supplies electricity for the town. The capacity of the power plant is 12 megawatts (MW) and the average household consumes 8,000 kilowatt hours (kWh) of electrical energy each year. The price paid to the electric utility by West Fremont residents for this energy is $0.10 per kWh. The town leaders are considering a plan, the West Fremont Wind Project (WFWP), to generate their own electricity using 10 wind turbines that would be located on the wooded ridges surrounding the town. Each wind turbine would have a capacity of 1.2 MW and each would cost the town $3 million to purchase, finance, and operate for 25 years. (a) Assuming that the existing power plant can operate at full capacity for 8,000 hrs/yr, how many kWh of electricity can be produced by the plant in a year? (b) At the current rate of electrical energy use per household, how many kWh of electrical energy does the community consume in one year? (c) Compare your answers in (a) and (b) and explain why you would or would not expect the numbers to be the same. (d) Assuming that the electrical energy needs of the community do not change during the 25-year lifetime of the wind turbines, what would be the cost to the community of the electricity supplied by the WFWP over 25 years? Express your answer in dollars/kWh. (e) Identify and explain TWO environmental benefits to West Fremont of switching from coal to wind power and TWO environmental costs to West Fremont of switching from coal to wind power. 3. Radioactive isotopes are widely used in the field of medicine, in the generation of electricity, and in the military. The use of radioactive isotopes has increased significantly over the past fifty years, leading to a corresponding increase in the amount of radioactive waste produced. The question of how to deal with radioactive waste is a topic of ongoing environmental concern. (a) Explain how the properties of low-level radioactive waste differ from those of high-level radioactive waste and how these properties lead to different storage requirements. For one of the two types of radioactive waste, give an example of a specific isotope that may be present in the waste, and explain how human activity generates the waste. (b) The United States Department of Energy recently chose Yucca Mountain in Nevada as the site for the deep underground burial of high-level radioactive waste. Describe THREE characteristics of an ideal deep underground storage site for high-level radioactive waste. (c) Identify TWO other options that have been suggested for the long-term management of radioactive waste. Discuss the feasibility of each method. (d) Exposure to high levels of ionizing radiation has adverse effects on human health and can result in immediate death. Identify one sublethal adverse effect on human health that can result from exposure to ionizing radiation, and explain how this effect is caused by the radiation. Copyright © 2004 by College Entrance Examination Board. All rights reserved. Visit apcentral.collegeboard.com (for AP professionals) and www.collegeboard.com/apstudents (for AP students and parents). GO ON TO THE NEXT PAGE. 3 2004 AP® ENVIRONMENTAL SCIENCE FREE-RESPONSE QUESTIONS 4. Suppose that you have just started a summer internship working for a cooperative extension service, where you will collect soil samples, conduct laboratory and field tests, and make recommendations on soil conservation and agricultural practices. (a) Identify and describe one chemical soil test and one physical soil test that could be performed and explain how the results of these tests will allow the cooperative extension service to make specific recommendations for sustainable agriculture. (b) Explain one advantage and one disadvantage to using inorganic commercial fertilizers. (c) Describe TWO soil conservation practices that are designed to decrease soil erosion. (d) Identify one biome that is characterized by soil that is rich in humus. Describe how humus originated in the soils of this biome and TWO ways that humus improves soil conditions for plant growth. END OF EXAMINATION 4 AP® Environmental Science 2003 Free-Response Questions The materials included in these files are intended for use by AP teachers for course and exam preparation; permission for any other use must be sought from the Advanced Placement Program®. Teachers may reproduce them, in whole or in part, in limited quantities for noncommercial, face-to-face teaching purposes. This permission does not apply to any third-party copyrights contained herein. This material may not be mass distributed, electronically or otherwise. These materials and any copies made of them may not be resold, and the copyright notices must be retained as they appear here. These materials were produced by Educational Testing Service® (ETS®), which develops and administers the examinations of the Advanced Placement Program for the College Board. The College Board and Educational Testing Service (ETS) are dedicated to the principle of equal opportunity, and their programs, services, and employment policies are guided by that principle. The College Board is a national nonprofit membership association whose mission is to prepare, inspire, and connect students to college and opportunity. Founded in 1900, the association is composed of more than 4,300 schools, colleges, universities, and other educational organizations. Each year, the College Board serves over three million students and their parents, 22,000 high schools, and 3,500 colleges through major programs and services in college admissions, guidance, assessment, financial aid, enrollment, and teaching and learning. Among its best-known programs are the SAT®, the PSAT/NMSQT®, and the Advanced Placement Program® (AP®). The College Board is committed to the principles of equity and excellence, and that commitment is embodied in all of its programs, services, activities, and concerns. For further information, visit www.collegeboard.com Copyright © 2003 College Entrance Examination Board. All rights reserved. College Board, Advanced Placement Program, AP, AP Vertical Teams, APCD, Pacesetter, Pre-AP, SAT, Student Search Service, and the acorn logo are registered trademarks of the College Entrance Examination Board. AP Central is a trademark owned by the College Entrance Examination Board. PSAT/NMSQT is a registered trademark jointly owned by the College Entrance Examination Board and the National Merit Scholarship Corporation. Educational Testing Service and ETS are registered trademarks of Educational Testing Service. Other products and services may be trademarks of their respective owners. For the College Board’s online home for AP professionals, visit AP Central at apcentral.collegeboard.com. 2003 AP® ENVIRONMENTAL SCIENCE FREE-RESPONSE QUESTIONS ENVIRONMENTAL SCIENCE SECTION II Time—90 minutes 4 Questions Directions: Answer all four questions, which are weighted equally; the suggested time is about 22 minutes for answering each question. Write all your answers on the pages following the questions in the pink booklet. Where calculations are required, clearly show how you arrived at your answer. Where explanation or discussion is required, support your answers with relevant information and/or specific examples. 1. Read the following article from the Fremont Examiner. (a) Support Dr. Tate’s assertion that “the leaf litter is critical to the survival of local species of forest plants.” Include in your discussion the roles of leaf litter in a deciduous forest ecosystem. (b) Describe THREE abiotic changes that would be likely to result if the exotic worms consumed all the leaf litter in a single year. (c) For one of the changes you identified in part (b), explain how the change could set the stage for the takeover of Japanese stilt grass or other exotic species. (d) Design a controlled experiment to determine whether the worms, in fact, do change the forest ecosystem. Identify the environmental factor you will measure, and include the specific hypothesis you will test and the data you will collect. Copyright © 2003 by College Entrance Examination Board. All rights reserved. Available to AP professionals at apcentral.collegeboard.com and to students and parents at www.collegeboard.com/apstudents. GO ON TO THE NEXT PAGE. 2 2003 AP® ENVIRONMENTAL SCIENCE FREE-RESPONSE QUESTIONS 2. A certain fictional country called Industria is tracking its population data. In 1855, the first year vital statistics were reported for the country, the population was 1.6 million, with a crude birth rate of 43 per 1,000. At that time the population of Industria was growing quite slowly, because of the high death rate of 41 per 1,000. In 1875 the population began to grow very rapidly as the birth rate remained at its 1855 level, while the crude death rate dropped dramatically to 20 per 1,000. Population growth continued to increase in the small country into the late 1800’s, even though birth rates began to decline slowly. In 1895 the crude birth rate had dropped to 37, and the death rate to 12 per 1,000. In that year (1895) a complete census revealed that the population of Industria had grown to 2.5 million. By 1950 population growth gradually began to decline as the death rate remained at its 1895 level, while the birth rate continued to decline to 22 per 1,000. In 1977 vital statistics revealed that the death rate was 10 per 1,000, and that population growth had slowed even more to an annual rate of 0.4%. By 1990 Industria had reduced its birth rate to that of its now constant, low death rate, and the population transition was complete. (a) On the axes below, plot the crude birth-rate data from 1855 to 1990. Now plot the crude death-rate data on the same axes. Clearly label the axes and the curves. (b) What was the annual growth rate of Industria in 1950 ? What was the birth rate in Industria in 1977 ? (c) Indicate TWO factors that might have accounted for the rapid decline in the death rate in Industria between 1855 and 1895. Indicate one specific reason why the birth rate might have been so high in 1855 and was so slow to decrease between 1855 and 1950. (d) Determine what the population size of Industria would have been in 1951 if the population had continued to grow at the annual rate of growth recorded for Industria in 1895. Copyright © 2003 by College Entrance Examination Board. All rights reserved. Available to AP professionals at apcentral.collegeboard.com and to students and parents at www.collegeboard.com/apstudents. GO ON TO THE NEXT PAGE. 3 2003 AP® ENVIRONMENTAL SCIENCE FREE-RESPONSE QUESTIONS 3. Environmental conditions in coastal estuaries vary hourly and seasonally. (a) Discuss TWO important causes for the variation in the temperature and/or salinity of an estuary. Be sure to include the connection between each cause and temperature and/or salinity. (b) Discuss TWO roles that coastal wetlands play that are ecologically important, and TWO roles that wetlands play that are economically important. (c) Identify and explain THREE ways in which humans have had a negative impact on or have degraded coastal wetlands. (d) Choose one of the negative human impacts you identified in part (c), and explain one environmental policy and one economic incentive that could have prevented it. 4. The American whooping crane and the California condor are two of North America’s largest birds. Although both are rare and endangered, they are protected, and large preserves are available for them. The two species, however, seem to be responding differently to these conservation efforts. In 1937, the whooping crane population was reduced to 14 individuals. It has since recovered; currently more than 200 birds live and breed in the wild. In the preservation of endangered species, the whooping crane is a success story. On the other hand, the California condor population declined rapidly so that no birds remained in the wild between 1987 and 1992. Condors were reintroduced into the wild after 1992 and approximately 50 condors currently live in the wild in California and Arizona. However, the recovery program cannot yet be considered a success. (a) Identify and describe TWO major causes for the original decline of these species. (You may describe one cause for each species or two causes for one species.) (b) Describe TWO measures that have been taken to protect these species. (Specify which of the species benefited from each measure.) (c) Describe TWO important characteristics of an endangered species that would cause it to be slow to recover. (d) Make one economic or ecological argument for protecting the condor, the whooping crane, or another endangered species that you identify and make one economic or ecological argument against protecting it. END OF EXAMINATION Copyright © 2003 by College Entrance Examination Board. All rights reserved. Available to AP professionals at apcentral.collegeboard.com and to students and parents at www.collegeboard.com/apstudents. 4 $3Environmental Science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® ENVIRONMENTAL SCIENCE FREE-RESPONSE QUESTIONS ENVIRONMENTAL SCIENCE SECTION II Time—90 minutes 4 Questions Directions: Answer all four questions, which are weighted equally; the suggested time is about 22 minutes for answering each question. Write all your answers on the pages following the questions in this booklet. Where calculations are required, clearly show how you arrived at your answer. Where explanation or discussion is required, support your answers with relevant information and/or specific examples. 1. Electric vehicles often have been proposed as an environmentally sound alternative to the gasoline engine for transportation. In response to state initiatives, several car manufacturers now include electric vehicles among their available models. In spite of these state initiatives, the penetration of electric vehicles into the transportation sector of the United States, as well as other countries, remains modest. (a) Identify and describe two environmental benefits to using electric vehicles in place of gasoline-powered engines for transportation. (b) Estimate the potential reduction in petroleum consumption (in gallons of gasoline per year) that could be achieved in the United States by introducing electric vehicles under the following assumptions: 1. The mileage rate for the average car is 25 miles per gallon of gasoline. 2. The average car is driven 10,000 miles per year. 3. The United States has 150 million cars. 4. 10 percent of United States cars could be replaced with electric vehicles. (c) Some people have suggested that electric vehicles only shift the emission of air pollutants from dispersed sources to point sources. Explain and defend or refute this statement. (d) Propose two potential new United States government policies that would encourage the widespread use of electric vehicles. Explain. 2. The Colorado River runs 1,450 miles from the headwaters of the Rocky Mountains to the Gulf of California. The river has many dams, aqueducts, and canals that divert water in order to supply water for electricity, irrigation, recreation, and domestic use. (a) Describe and discuss two environmental problems that are associated with water diversion. (b) If there is a shortage of water, choices will have to be made as to whether water should be diverted to urban areas, agricultural areas, or natural ecosystems. Make an argument for diverting water for urban consumption and an argument for permitting the flow of water to natural areas. (c) Identify another example (other than the Colorado River) of a large-scale water-diversion project. Discuss two environmental problems that have resulted, or might result, from this project. Copyright © 2002 by College Entrance Examination Board. All rights reserved. Advanced Placement Program and AP are registered trademarks of the College Entrance Examination Board. 2 GO ON TO THE NEXT PAGE. 2002 AP® ENVIRONMENTAL SCIENCE FREE-RESPONSE QUESTIONS 3. An experiment is performed to test the toxicity of copper sulfate (CuSO4) using brine shrimp as a test organism. Six different concentrations of CuSO4 solution are prepared in separate petri dishes, and 100 brine shrimp are placed in each dish. After 48 hours, the number of brine shrimp that have died is counted and recorded. The results of this experiment are shown in the table below. CuSO4 Concentration (%) Number of Dead Brine Shrimp < 0.0001 0.001 0.01 0.1 1 10 10 10 20 55 90 100 (a) Plot these data on the blank semi-log graph provided below. Draw a smooth curve through the data points to illustrate the overall trend of the data. (b) Explain the meaning of the term LD50 (ED50). What is the LD50 concentration of CuSO4 for brine shrimp? (c) Explain the meaning of the term “threshold level of toxicity”. What is the threshold level of toxicity of CuSO4 for brine shrimp? Label this point on the graph. (d) Provide one argument for extending these toxicity results to humans and one argument against doing so. Copyright © 2002 by College Entrance Examination Board. All rights reserved. Advanced Placement Program and AP are registered trademarks of the College Entrance Examination Board. 3 GO ON TO THE NEXT PAGE. 2002 AP® ENVIRONMENTAL SCIENCE FREE-RESPONSE QUESTIONS 4. Read the article below and answer the questions that follow. (a) Describe what an El Niño is and clearly indicate where it occurs. (b) Describe the connection between the climate change associated with an El Niño and the transmission of diseases. Explain whether the article is correct in its reporting of the various disease epidemics that occur in response to an El Niño. (c) People in what part of the world would be most likely to be affected by this link between El Niño and disease? (d) Clearly describe two other important environmental problems associated with ENSOs. END OF EXAMINATION Copyright © 2002 by College Entrance Examination Board. All rights reserved. Advanced Placement Program and AP are registered trademarks of the College Entrance Examination Board. 4 AP Environmental Science 2001 Free-Response Questions The materials included in these files are intended for use by AP teachers for course and exam preparation in the classroom; permission for any other use must be sought from the Advanced Placement Program. Teachers may reproduce them, in whole or in part, in limited quantities, for face-to-face teaching purposes but may not mass distribute the materials, electronically or otherwise. These materials and any copies made of them may not be resold, and the copyright notices must be retained as they appear here. This permission does not apply to any third-party copyrights contained herein. These materials were produced by Educational Testing Service (ETS), which develops and administers the examinations of the Advanced Placement Program for the College Board. The College Board and Educational Testing Service (ETS) are dedicated to the principle of equal opportunity, and their programs, services, and employment policies are guided by that principle. The College Board is a national nonprofit membership association dedicated to preparing, inspiring, and connecting students to college and opportunity. Founded in 1900, the association is composed of more than 3,900 schools, colleges, universities, and other educational organizations. Each year, the College Board serves over three million students and their parents, 22,000 high schools, and 3,500 colleges, through major programs and services in college admission, guidance, assessment, financial aid, enrollment, and teaching and learning. Among its best-known programs are the SAT®, the PSAT/NMSQT™, the Advanced Placement Program® (AP®), and Pacesetter®. The College Board is committed to the principles of equity and excellence, and that commitment is embodied in all of its programs, services, activities, and concerns. Copyright © 2001 by College Entrance Examination Board. All rights reserved. College Board, Advanced Placement Program, AP, and the acorn logo are registered trademarks of the College Entrance Examination Board. 2001 AP® ENVIRONMENTAL SCIENCE FREE-RESPONSE QUESTIONS ENVIRONMENTAL SCIENCE SECTION II Time—90 minutes NO CALCULATORS MAY BE USED ON THIS EXAMINATION 4 Questions Directions: Answer all four questions, which are weighted equally; the suggested time is about 22 minutes for answering each question. Write all your answers on the pages following the questions in the pink booklet. Where calculations are required, clearly show how you arrived at your answer. Where explanation or discussion is required, support your answers with relevant information and/or specific examples. 1. Answer the questions below regarding the heating of a house in the Midwestern United States. Assume the following. • The house has 2,000 square feet of living space. • 80,000 BTUs of heat per square foot are required to heat the house for the winter. • Natural gas is available at a cost of $5.00 per thousand cubic feet. • One cubic foot of natural gas supplies 1,000 BTUs of heat energy. • The furnace in the house is 80 percent efficient. (a) Calculate the following, showing all the steps of your calculations, including units. (i) The number of cubic feet of natural gas required to heat the house for one winter (ii) The cost of heating the house for one winter (b) Identify and describe three actions the residents of the house could take to conserve heat energy and lower the cost of heating the house. (c) The residents decide to supplement the heating of the house by using a wood-burning stove. Discuss two environmental impacts, one positive and one negative, of using the wood-burning stove. Copyright © 2001 by College Entrance Examination Board. All rights reserved. Advanced Placement Program and AP are registered trademarks of the College Entrance Examination Board. GO ON TO THE NEXT PAGE. 2 2001 AP® ENVIRONMENTAL SCIENCE FREE-RESPONSE QUESTIONS 2. After reading the following excerpt from an article about the interrelationships among organisms in an oak forest, answer parts (a), (b), and (c), which follow. Chain Reactions Linking Acorns to Gypsy Moth Outbreaks and Lyme Disease Risk Oak trees (Quercus spp.) produce large autumnal acorn crops every two to five years, and produce few or no acorns during intervening years. Acorns are a critical food for white-footed mice (Peromyscus leucopus). Mice are important predators of the pupal stage of the gypsy moth (Lymantria dispar). This introduced insect periodically undergoes outbreaks that defoliate millions of hectares of oak forests, decreasing tree growth, survival, and acorn crop production. An abundance of acorns provides food for white-tailed deer (Odocoileus virginianus). Mice and deer are the primary hosts of the black-legged tick (Ixodes scapularis), which carries Lyme disease. (a) In the space provided below, diagram a food web based on the interrelationships of the organisms identified in the excerpt. (b) Design a controlled experiment that tests the relationship between acorn production and gypsy moth population. Include the hypothesis that the experiment tests. (c) Briefly describe a strategy that uses integrated pest management for the control of the black-legged tick population. Copyright © 2001 by College Entrance Examination Board. All rights reserved. Advanced Placement Program and AP are registered trademarks of the College Entrance Examination Board. GO ON TO THE NEXT PAGE. 3 2001 AP® ENVIRONMENTAL SCIENCE FREE-RESPONSE QUESTIONS 3. In recent years, results from scientific studies have increased public awareness of the possible damage to human health from exposure to indoor air pollution. (a) Identify two specific indoor air pollutants and, for each, discuss the following. (i) The type of building most affected by the pollutant (ii) Source(s) of the pollutant (iii) The pollutant’s effects on human health (iv) The method(s) of prevention or cleanup of the pollutant (b) According to the Environmental Protection Agency, at least 17 percent of the four million commercial buildings in the United States can be considered “sick buildings.” (i) Explain what is meant by the term “sick building.” (ii) Describe the criteria used for determining whether a building is “sick.” Copyright © 2001 by College Entrance Examination Board. All rights reserved. Advanced Placement Program and AP are registered trademarks of the College Entrance Examination Board. GO ON TO THE NEXT PAGE. 4 2001 AP® ENVIRONMENTAL SCIENCE FREE-RESPONSE QUESTIONS 4. Students in an environmental science class at Fremont High School tested the water quality in a stream near their school. They were concerned about the possible pollution of the stream, which flows through a farm on which hogs are raised. Shown below are a diagram that indicates the sites where the students collected water samples (labeled A through D, upstream to downstream) and a table of the results of the students’ water tests. Results of Water Tests A B C D Dissolved Oxygen (ppm) 6.4 ± 0.3 2.5 ± 0.1 3.0 ± 0.2 5.8 ± 0.2 Phosphate (ppm) 0.9 ± 0.05 1.2 ± 0.09 1.1 ± 0.08 1.0 ± 0.09 Nitrate (ppm) 0.9 ± 0.3 19.3 ± 1.1 12.5 ± 1.0 6.2 ± 0.5 pH 5.5 5.4 5.6 5.4 (a) Assess the likelihood that animal waste is contaminating the water. Discuss the scientific basis of your assessment. (b) Describe two additional tests that could be used in monitoring the quality of the water in the stream. For each test, describe the patterns you would expect from sites A through D. (c) Describe a sequence of ecological changes that might result from the discharge of animal waste into a body of water. (d) The Clean Water Act was first passed in the United States in 1972 and has been amended several times since then. Describe two specific provisions of this legislation that would be likely to apply to the quality of the stream water. END OF EXAMINATION Copyright © 2001 by College Entrance Examination Board. All rights reserved. Advanced Placement Program and AP are registered trademarks of the College Entrance Examination Board. 5 2000 Advanced Placement Program® Free-Response Questions The materials included in these files are intended for use by AP® teachers for course and exam preparation in the classroom; permission for any other use must be sought from the Advanced Placement Program. Teachers may reproduce them, in whole or in part, in limited quantities, for face-to-face teaching purposes but may not mass distribute the materials, electronically or otherwise. These materials and any copies made of them may not be resold, and the copyright notices must be retained as they appear here. This permission does not apply to any third-party copyrights contained herein. These materials were produced by Educational Testing Service (ETS), which develops and administers the examinations of the Advanced Placement Program for the College Board. The College Board and Educational Testing Service (ETS) are dedicated to the principle of equal opportunity, and their programs, services, and employment policies are guided by that principle. The College Board is a national nonprofit membership association dedicated to preparing, inspiring, and connecting students to college and opportunity. Founded in 1900, the association is composed of more than 3,800 schools, colleges, universities, and other educational organizations. Each year, the College Board serves over three million students and their parents, 22,000 high schools, and 5,000 colleges, through major programs and services in college admission, guidance, assessment, financial aid, enrollment, and teaching and learning. Among its best-known programs are the SAT®, the PSAT/NMSQT®, the Advanced Placement Program® (AP®), and Pacesetter®. The College Board is committed to the principles of equity and excellence, and that commitment is embodied in all of its programs, services, activities, and concerns. Copyright © 2000 by College Entrance Examination Board and Educational Testing Service. All rights reserved. College Board, Advanced Placement Program, AP, and the acorn logo are registered trademarks of the College Entrance Examination Board. 2000 AP® ENVIRONMENTAL SCIENCE FREE-RESPONSE QUESTIONS ENVIRONMENTAL SCIENCE SECTION II Time—90 minutes 4 Questions Directions: Answer all four questions, which are weighted equally; the suggested time is about 22 minutes for answering each question. Write all your answers on the pages following the questions in this booklet, NOT on the green insert. Where calculations are required, clearly show how you arrived at your answer. Where explanation or discussion is required, support your answers with relevant information and/or specific examples. 1. A large, coal-fired electric power plant produces 12 million kilowatt-hours of electricity each day. Assume that an input of 10,000 BTU’s of heat is required to produce an output of 1 kilowatt-hour of electricity. (a) Showing all steps in your calculations, determine the number of (i) BTU’s of heat needed to generate the electricity produced by the power plant each day, (ii) pounds of coal consumed by the power plant each day, assuming that one pound of coal yields 5,000 BTU’s of heat, (iii) pounds of sulfur released by the power plant each day, assuming that the coal contains one percent sulfur by weight. (b) The Environmental Protection Agency (EPA) standard for power plants such as this one is that no more than 1.2 pounds of sulfur be emitted per million BTU’s of heat generated. Using the results in part (a), determine whether the power plant meets the EPA standard. (c) Describe two ways by which a fuel-burning electric power plant can reduce its sulfur emissions. (d) Discuss why sulfur emissions from coal-fired power plants are considered an environmental problem and describe one negative effect on an ecosystem that has been associated with sulfur emissions. Copyright © 2000 College Entrance Examination Board and Educational Testing Service. All rights reserved. AP is a registered trademark of the College Entrance Examination Board. GO ON TO THE NEXT PAGE. -2- 2000 AP® ENVIRONMENTAL SCIENCE FREE-RESPONSE QUESTIONS 2. After reading the following editorial from The Fremont Daily, answer the questions that follow. IS RECYCLING SMART ECONOMICS? Debates about recycling often become highly charged and passionate. Over the past decade some headlines have heralded that “trash is treasure” while others have proclaimed that “recycling is garbage.” The antagonists in these debates are disagreeing over public policy and its role in shaping decisions about resource use. Both sides in these debates frequently have broad policy agendas that go far beyond choosing the most efficient way to manage solid waste. Both sides also promote their political agendas with unsupported assertions and incomplete information. Determining what amount of recycling will result in efficient resource use requires systematic analysis. Proponents of recycling argue that recycling saves resources. For example, most manufacturers of aluminum cans currently depend on recycled aluminum for more than 50% of their needs. This recycled input reduces the economic and environmental costs associated with mining and landfills. A common argument for the antirecycling side is that recycling wastes resources. It takes resources to recycle. For example, it takes human effort to sort aluminum cans from other trash and energy to move aluminum cans from the consumer back to the manufacturer. It may not make economic sense to recycle all materials or all of any single material, but numerous studies have shown that there are net benefits to society at low or modest levels of recycling most materials. The question is, Which has the higher environmental cost: using recovered materials or using virgin materials? Do recovered or virgin materials cost more in resources? The answer is complex and changing. Your next environmental decision is fast approaching. Should you put this copy of The Fremont Daily in the recycling bin or should you put it in the trash? (a) Consider the arguments regarding aluminum presented in the editorial, then make (i) a similar argument in favor of recycling the newspaper, and (ii) a similar argument against recycling the newspaper. (b) For each of the following, describe two pieces of scientific information that would be needed to evaluate (i) the environmental benefits of recycling the newspaper, and (ii) the environmental costs of recycling the newspaper. (c) If a community can afford to begin a recycling program for either aluminum or newspaper, but not both, which one would you recommend to be recycled? Provide two reasons why your recommendation is better than the alternative. (d) Discuss two difficulties that the community might face in implementing the recycling program in part (c). Copyright © 2000 College Entrance Examination Board and Educational Testing Service. All rights reserved. AP is a registered trademark of the College Entrance Examination Board. GO ON TO THE NEXT PAGE. -3- 2000 AP® ENVIRONMENTAL SCIENCE FREE-RESPONSE QUESTIONS 3. Species such as the dusky seaside sparrow, the passenger pigeon, and the woolly mammoth are extinct. Populations of other species have declined to the point where they are designated as threatened or endangered. (a) Identify one threatened or endangered species and explain why its population has declined. (b) Describe three characteristics of organisms that would make them particularly vulnerable to extinction. (c) Present three arguments in favor of the maintenance of biodiversity. (d) Name and describe one United States federal law or one international treaty that is intended to prevent the extinction of species. Copyright © 2000 College Entrance Examination Board and Educational Testing Service. All rights reserved. AP is a registered trademark of the College Entrance Examination Board. GO ON TO THE NEXT PAGE. -4- 2000 AP® ENVIRONMENTAL SCIENCE FREE-RESPONSE QUESTIONS 4. The figures above show the age structures of human populations in three countries, X, Y and Z. (a) Which of the three countries has the largest rate of population growth? Which has the smallest rate? Explain. (b) Compare the infant mortality rates that are likely in Countries X and Y. Explain your reasoning. (c) Describe the changes in both the birth rate and the death rate for a country making the transition from a preindustrial society to an industrial society. (d) Describe one incentive that the government of a country could offer its citizens that would favor a reduction in the growth rate of its population. Explain how this incentive would work, and describe one possible drawback. END OF EXAMINATION Copyright © 2000 College Entrance Examination Board and Educational Testing Service. All rights reserved. AP is a registered trademark of the College Entrance Examination Board. -5- AP Environmental Science 1999 Free-Response Questions The materials included in these files are intended for non-commercial use by AP teachers for course and exam preparation; permission for any other use must be sought from the Advanced Placement Program. Teachers may reproduce them, in whole or in part, in limited quantities, for face-to-face teaching purposes but may not mass distribute the materials, electronically or otherwise. These materials and any copies made of them may not be resold, and the copyright notices must be retained as they appear here. This permission does not apply to any third-party copyrights contained herein. These materials were produced by Educational Testing Service (ETS), which develops and administers the examinations of the Advanced Placement Program for the College Board. The College Board and Educational Testing Service (ETS) are dedicated to the principle of equal opportunity, and their programs, services, and employment policies are guided by that principle. The College Board is a national nonprofit membership association dedicated to preparing, inspiring, and connecting students to college and opportunity. Founded in 1900, the association is composed of more than 3,900 schools, colleges, universities, and other educational organizations. Each year, the College Board serves over three million students and their parents, 22,000 high schools, and 3,500 colleges, through major programs and services in college admission, guidance, assessment, financial aid, enrollment, and teaching and learning. Among its best-known programs are the SAT®, the PSAT/NMSQT™, the Advanced Placement Program® (AP®), and Pacesetter®. The College Board is committed to the principles of equity and excellence, and that commitment is embodied in all of its programs, services, activities, and concerns. Copyright © 2001 by College Entrance Examination Board. All rights reserved. College Board, Advanced Placement Program, AP, and the acorn logo are registered trademarks of the College Entrance Examination Board. -2ENVIRONMENTAL SCIENCE SECTION II Time—90 minutes 4 Questions Directions: Answer all four questions, which are weighted equally; the suggested time is about 22 minutes for answering each question. Write all your answers on the pages following the questions in the pink booklet, NOT on the green insert. Where calculations are required, clearly show how you arrived at your answer. Where explanation or discussion is required, support your answers with relevant information and/or specific examples. 1. On a field trip to two local ponds, a group of students observed a difference between the two ponds in the diversity of worms and insect larvae living in the mud and debris near the edges of the ponds. Numerous factors, both biotic and abiotic, influence the distribution of aquatic organisms. (a) The students decided that they would investigate some of the abiotic factors. List three water-quality tests that could be conducted and explain what information each test provides. Include in your answers a description of the impact of each factor on the distribution of aquatic organisms. (b) Larvae of a certain insect are found in pond A but not in pond B. Design a controlled experiment that would help explain the observed distribution of these insect larvae. Be sure to include the following in your design. 1. 2. 3. 4. Formulate a hypothesis. Identify the variable that will be manipulated. Outline the field and/or laboratory procedures that will be followed. Describe what data you will collect. Discuss the possible results and relate them to the distribution of the insect. (c) What are indicator species and how are they used to assess environmental quality? Give a specific example of such a species and its use. 2. The development of plans for long-term resource management depends on understanding the patterns and consequences of resource use. (a) Describe what makes a resource renewable or nonrenewable. Give a specific example of a renewable resource and of a nonrenewable resource. (b) Describe and compare total resource use per capita in developed and developing countries. (c) What is meant by sustainable resource use? Give an example. (d) Economic policies and practices affect society’s progress toward achieving sustainable resource use. Discuss one policy or practice that facilitates this progress, and one that impedes it. -3- Ozone Carbon Monoxide Carbon Monoxide 0.160 0.140 0.120 0.100 0.080 0.060 0.040 0.020 0.000 19 1976 1977 1978 7 19 9 1980 1981 1982 19 83 19 84 8 19 5 1986 1987 1988 8 19 9 1990 1991 9 19 2 19 93 19 94 95 Ozone (ppm) ATMOSPHERIC CONCENTRATIONS OF OZONE AND CARBON MONOXIDE Year Particulates Lead Particulates 1.600 1.400 1.200 1.000 0.800 0.600 0.400 0.200 0.000 19 1976 1977 1978 7 19 9 1980 1981 1982 19 83 19 84 8 19 5 1986 1987 1988 8 19 9 1990 1991 9 19 2 19 93 19 94 95 Lead (µg m–3) ATMOSPHERIC CONCENTRATIONS OF LEAD AND PARTICULATE MATTER Year 3. The six criteria pollutants used by the Environmental Protection Agency to assess air quality in the United States are NO 2 , SO 2 , carbon monoxide, lead, ozone, and particulates. The graphs above show trends in the concentration of four of these in a certain city in the United States. (a) Describe and compare the concentration trends for ozone and lead. Calculate the percentage change in each from 1978 to 1988. (b) For either ozone or lead, identify the major source(s) of that pollutant and describe the main physiological effects in humans. (c) For either particulates or carbon monoxide, identify the major source(s) of that pollutant and describe the most effective method of reducing the concentration of the pollutant in the atmosphere. -44. The following is an excerpt from a newspaper article describing a controversy. Pesticide Use in Agriculture—A Controversy Recently, Jonesville County inhabitants have been embroiled in a controversy regarding the use of pesticides on crops grown in the county. The Jonesville Express interviewed county residents for opinions on pesticide use. Below is a sampling of their responses. Charles Ehler, farmer: “I’m not going to use those pesticides because I don’t want to end up with leukemia.” Maurice Gordon, farmer: “The people who oppose the use of pesticides should have to decide which third of the world would starve.” Wendell Mullison, chemical salesman: “The health risks are minimal because these chemicals have been intensively tested by the chemical companies.” Robert Rodriguez, Environmental Protection Agency employee: “I worry about pesticides that find their way into groundwater. My agency has trouble keeping up with the new developments in farm chemistry. We don’t even test the water for most of the pesticides that are in use today.” Bessie Smith, 80-year-old resident: “I’m against pesticides. When those planes spray on the farm next to me, most of those chemicals end up in my yard.” Alice Evans, farmer: “I couldn’t earn a living without pesticides. My farm would not make a profit.” Judy Johnson, college professor: “We’re in a vicious cycle. We develop pesticides, apply them, and the pests evolve resistance. Then we have to do it all over again.” Ben Jackson, librarian: “Pesticides are much safer than they used to be. The newer pesticides only affect specific pests and break down more quickly in the environment.” (a) Select four of the people interviewed. Provide a concise argument, based on scientific principles, that supports or refutes each individual’s viewpoint. (b) Identify one specific pest and explain its adverse effects on either agriculture or human health. Describe a viable method, other than the use of pesticides, of controlling this pest. END OF EXAMINATION • MAKE SURE YOU HAVE COMPLETED THE IDENTIFICATION INFORMATION AS REQUESTED ON THE BACK COVER OF THIS BOOKLET. • CHECK TO SEE THAT YOUR AP NUMBER APPEARS IN THE BOX ON THE BACK COVER. • MAKE SURE YOU HAVE USED THE SAME SET OF AP NUMBER LABELS ON ALL AP EXAMINATIONS YOU HAVE TAKEN THIS YEAR.