APES Unit 1 - Multiple Choice

ANSWERS: 1. B—Nitrifying bacteria or lighting converts atmospheric nitrogen N2 to ammonia. 2. A—Certain bacteria are specialized in fixing nitrogen, in association with plants such as soybeans and other legumes. Other types of bacteria perform nitrification: converting ammonium ions into nitrite ions, and then into nitrate ions. Finally, other bacteria perform denitrification, the reduction of nitrates back into nitrogen gas. 3. C—The largest reservoir of nitrogen is the atmosphere, which is about 80% free nitrogen (N2) and contains 3,870,000,000 tetragrams of nitrogen. 4. B—The Sun powers the movement of water through evaporation and transpiration. 5. C—Ice caps (and glaciers) store almost 70% of the Earth’s total freshwater. 6. B—Arrows in a food web depict the flow of energy between trophic levels. 7. D—The amount of energy available decreases up the food chain, so the organisms at the highest trophic level would have the fewest kilojoules of energy available. The killer whale is a top predator (quaternary consumer). 8. D—Assuming only approximately 10% of biomass is available to be transferred to the next trophic level, 1,000kg of phytoplankton would be needed because of the four different energy transfers in this food web. [1,000kg phytoplankton ×0.10=100kg available to herbivorous zooplankton; 100kg zooplankton ×0.10=10kg available to small fish; 10kg small fish ×0.10=1kg of large fish biomass] 9. D—Since both species eat the same food, there is competition for a limited resource in the confined space. 10. C—The two organisms both benefit from the relationship. 11. A—The two bird species are using the same resource in slightly different ways to reduce the negative impact of competition on the two species. 12. A—Warmer average global temperatures would expand the range of biomes currently found at midlatitudes. 13. B—Net primary productivity (NPP) is higher in biomes that are warm year-round and receive abundant rainfall and sunlight to encourage the growth of producers, which are all characteristics of tropical rain forests. 14. B—Tropical rain forests have a yearlong growing season and more than 60 inches of rain per year. The warm climate and the rainfall leads to high levels of photosynthesis in the numerous plant species that inhabit the biome. 15. B—Freshwater wetlands have trees with roots that are submerged in water. The trees drop their leaves, and the water traps organic materials released from decomposition. The wetlands also trap pollutants. 16. A—Corals live in vast colonies off the coast and create a reef that provides habitat for a variety of organisms, including algae, tropical fish, and birds. 17. D—Rivers carry runoff from rain or snow. Turbulent water, known as rapids, form from the fast-moving water flow. 18. A—Carbon is converted from atmospheric CO2 to organic carbon compounds via photosynthesis, and carbon sequestered by the ocean buffers ocean pH. 19. D—Burning fossil fuels is a source because it releases carbon that has been stored in coal, oil, or natural gas, which are carbon sinks. 20. A—Carbon dioxide can move into plants to be stored as glucose much more quickly than sedimentary rocks and fossil fuels can be stored. Carbon compounds are held for the shortest amount of time in vegetation. 21. C—The phosphorus cycle does not have an atmospheric sink and is driven by weathering and upli. 22. B—The phosphates absorbed by animal tissue through consumption eventually return to the soil through the excretion of plants and animals and their decomposition aer death. 23. B—Phosphorus is a limiting factor in biological systems. By decreasing the amount of erosion, less phosphorus will run off into waterways and be available to algae to use for growth. 24. A—The ocean is the largest reservoir and over 70% of the Earth’s surface of water and therefore the greatest source for evaporation. 25. B—Gross primary productivity is defined as the total rate of photosynthesis in a given area. 26. D—Cellular respiration does not require sunlight, so it can be measured in the dark. 27. C—Net primary productivity is the rate of energy storage by photosynthesizers aer subtracting energy used for cellular respiration in plants. 28. D—Through the process of photosynthesis, plants convert solar energy into chemical energy, which moves through the food chain when one organism feeds on another. 29. A—Net primary productivity is highest in areas where temperatures are warm and water and solar energy are abundant and encourage the growth of producers. 30. A—Phytoplankton uses solar energy to produce food; it is a producer. 31. A—10% of the kilocalories from net primary productivity would be available (2,000kilocalories/meter2/year×0.10=200kilocalories/meter2/year) 32. B—Energy lost is 90% per trophic level so 10% is transferred. If level 1 (primary producer) stores 10,000kcal of energy, then level 2 (primary consumer) would have 1,000kcal of energy available, level 3 (secondary consumer) would have 100kcal of energy available, and level 4 (tertiary consumer) would have 10kcal of energy available. (10,000kcal×0.10×0.10×0.10=10kcal) 33. C—The energy flows up the food web through trophic levels based on feeding relationships. APES Unit 1: Multiple Choice from AP Classroom Questions 1–3 refer to this diagram: 1. Which of the following processes is illustrated by the downward arrows from the atmosphere that show the conversion of nitrogen gas into usable forms available to producers? a. Nitrogen Assimilation b. Nitrogen fixation c. Photosynthesis d. Weathering 2. Which of the following types of organisms are required to complete the nitrogen cycle, including the process of denitrification? a. Bacteria b. Producers c. Consumers d. Fungi 3. The majority of the nitrogen on Earth can be found in which of the following reservoirs? a. Terrestrial plants b. Soil bacteria c. The atmosphere d. Sedimentary rock Questions 4–5 refer to this diagram: 4. Which of the following best identifies a key component of the hydrologic cycle that powers the movement of water and is missing from the diagram? a. Terrestrial animals b. The Sun c. Bacteria d. Volcanoes 5. Which of the following major reservoirs of freshwater are missing from the diagram? a. Fossil fuels b. Rocks c. Ice caps d. Algae Questions 6–8 refer to this diagram: 6. Which of the following best describes what is represented by the arrows in the food web? a. The photosynthesis rates of producers b. The flow of energy c. The movement of predators d. The decomposition of matter 7. Which trophic level has the least available energy in kilojoules in this food web? a. Phytoplankton b. Herbivorous zooplankton c. Baleen whale d. Killer whale 8. Based on the second law of thermodynamics, how much biomass of phytoplankton would be needed to produce 1 kilogram (kg) of large fish in this food web? a. 1g b. 10g c. 100kg d. 1,000kg Question 9 refers to this study: Six white-tailed deer and six sika deer were enclosed in a pasture for observation during an eight-year study in central Texas. White-tailed deer are a native species to central Texas, while sika deer are a nonnative species to central Texas. White-tailed deer feed on flowering plants and the tips of trees and shrubs but do not eat grass. Sika deer feed on flowering plants, the tips of trees and shrubs, and grass. All other grazing animals were kept out of the pasture during the study. The number of sika deer more than doubled aer the eight years, while the population of white-tailed deer decreased by 50 percent. 9. Which of the following statements best supports the results from the study? a. The sika deer are generalists, while the white-tailed deer are specialists. b. The sika deer out competed the white-tailed deer in consuming flowering plants and shrubs. c. Parasites infected the sika deer population but did not infect the white-tailed deer population. d. Change in the local climate reduced the availability of food resources for the white-tailed deer population. 10. In reef ecosystems, corals oen have microalgae living inside them. The algae supply the corals with nutrients, and the coral give shelter to the algae. Which of the following interactions best describes the relationship between the corals and the algae? a. Competition b. Predation c. Mutualism d. Parasitism 11. Which of the following best describes an example of resource partitioning in an ecosystem? a. Two different bird species feed from the same oak tree; one eats acorns, and the other eats insects in the bark. b. A tick uses a white-tailed deer as its host, consuming the deer’s blood as food. c. Two individuals from the same population of barn owls hunt for the same species of mouse during the night. d. A mason bee pollinates a variety of flowers in a botanical garden. 12. Which of the following describes the most likely change to terrestrial biomes resulting from warmer average global temperatures? a. The global distribution of midlatitude biomes, such as grasslands and temperate rain forests, would increase. b. Deciduous trees found in temperate seasonal forests would flower later in the year. c. The latitude range of tropical rain forests would narrow closer to the equator. d. High-latitude biomes, such as the tundra, would experience a decrease in net primary productivity. 13. Which of the following terrestrial biomes has the highest net primary productivity? a. Desert b. Tropical Rainforest c. Taiga d. Savanna 14. Which of the following terrestrial biomes has the highest primary productivity per unit area? a. Desert b. Tropical Rainforest c. Boreal forest d. Savanna 15. This biome contains a nutrient-rich environment created by falling leaves and trapped organic materials from the large trees, and it provides the ecosystem service of filtering pollutants from water. a. Coral reefs b. Freshwater wetlands c. Open ocean d. Rivers 16. This biome is found in shallow waters off the coastline and is Earth’s most biologically diverse marine biome. a. Coral reefs b. Freshwater wetlands c. Open ocean d. Rivers 17. This freshwater biome is characterized by fast-flowing water that can originate from underground springs or runoff, which carries sediment and organic material. a. Coral reefs b. Freshwater wetlands c. Open ocean d. Rivers Question 18 refers to this diagram: 18. Which of the following biogeochemical cycles includes the processes of buffering ocean pH and photosynthesis, as shown in the diagram? a. The Carbon Cycle b. The Nitrogen Cycle c. The Phosphorus Cycle d. The Potassium Cycle Questions 19 & 20 refer to this diagram: 19. Which of the following boxes represents a carbon source? a. A b. B c. C d. D 20. Which box represents a carbon sink that holds carbon compounds for the shortest period of time? a. A b. B c. C d. D Question 21 refers to this diagram: 21. The diagram above best illustrates major processes in which of the following biogeochemical cycles? a. The Carbon Cycle b. The Nitrogen Cycle c. The Phosphorus Cycle d. The Water Cycle Question 22 refers to this diagram: 22. Which of the following statements is best supported by the diagram of the phosphorus cycle? a. The largest reservoir of phosphorus is in the atmosphere. b. The phosphates absorbed by animal tissue through consumption eventually return to the soil. c. Plants take up the phosphate ions primarily from the metamorphic rocks. d. Phosphates are not soluble in water. Question 23 refers to this diagram: 23. Farmers in a suburban coastal town started using no-till agriculture, a practice that reduces soil erosion from their farmland. Use the image above to determine which of the following long-term effects no-till agriculture will have on the ecosystem surrounding the farmland. a. There will be an increased need for fertilizer on farmlands. b. There will be less algal growth in the nearby ocean. c. There will be less phosphorus pollution in the atmosphere. d. There will be an increased deposition of phosphorus-rich sediments. Question 24 refers to this diagram: 24. Based on the diagram, which of the following statements about the hydrologic cycle is true? a. Water from the ocean evaporates and condenses in the atmosphere. b. Surface runoff is the primary recharge of groundwater. c. Infiltration of water into the ground prevents water from returning to the oceanic reservoir. d. Evapotranspiration from plants decreases atmospheric water vapor. 25. The total rate of photosynthesis in a given area. a. Primary productivity b. Gross primary productivity c. Net primary productivity d. Cellular respiration 26. This rate of reaction can be measured in the dark by determining the amount of oxygen gas consumed in a period of time. a. Primary productivity b. Gross primary productivity c. Net primary productivity d. Cellular respiration 27. The energy available to consumers determined by subtracting the energy used by plants from the total energy transformed by the process of photosynthesis. a. Primary productivity b. Gross primary productivity c. Net primary productivity d. Cellular respiration 28. Which of the following best describes the flow of energy in most terrestrial and near-surface marine ecosystems? a. Decomposers break down dead or decaying organisms to release energy and nutrients to be used by producers. b. Chemoautotrophs use inorganic energy sources, such as hydrogen sulfide, to create organic compounds from carbon dioxide. c. Apex predators feed on other organisms, which releases heat that can be used by producers and primary consumers. d. Producers use energy from the sun to make organic matter, such as sugars, from carbon dioxide and water and are then consumed by organisms higher in the food chain. 29. Which of the following best describes a terrestrial ecosystem that will have the highest net primary productivity? a. Warm temperatures, high rainfall, and consistent sunlight b. Hot temperatures, low rainfall, and consistent sunlight c. Cold temperatures, high rainfall, and inconsistent sunlight d. Warm temperatures, low rainfall, and inconsistent sunlight 30. Which of the following trophic levels represents a primary producer in an aquatic food chain? a. Phytoplankton b. Herbivorous zooplankton c. Carnivorous zooplankton d. Baleen whale 31. A temperate grassland biome has a gross primary productivity of 3,480kilocalories/meter2/year and a net primary productivity of 2,000kilocalories/meter2/year. Which of the following is the approximate number of kilocalories/meter2/year available to herbivores in that biome? a. 200kilocalories/meter2/year b. 1,480kilocalories/meter2/year c. 2,000kilocalories/meter2/year d. 5,480kilocalories/meter2/year 32. Energy is transferred along food chains from one stage to the next. Which statement best explains how the energy is transferred? a. If a primary consumer stores 100kcal of energy, then a secondary consumer that feeds on the primary consumer will also have 100kcal of energy available. b. If a primary producer stores 10,000kcal of energy, then a tertiary consumer will have 10kcal of energy available. c. If a primary producer stores 100,000kcal of energy, then a secondary consumer will have 10,000kcal of energy available. d. If a secondary consumer stores 500kcal of energy, then a tertiary consumer that feeds on the secondary consumer will have 5,000kcal of energy available. Question 33 refers to this diagram: 33. Based on the food web shown above, which of the following correctly describes the flow of energy through the trophic levels from producers to quaternary consumers? a. Red-tailed hawk, grasshopper mouse, grasshopper, rattlesnake, brittlebrush b. Red-tailed hawk, rattlesnake, grasshopper mouse, grasshopper, brittlebrush c. Brittlebrush, grasshopper, grasshopper mouse, rattlesnake, red-tailed hawk d. Brittlebrush, red-tailed hawk, rattlesnake, grasshopper mouse, grasshopper