APES 2A

A 163 square-kilometer (km2) small island is found 2,000km from the mainland. A second, larger, 230,000km2 island is found 1,000km from the mainland. Based on the theory of island biogeography, which of the following statements is most likely true about the small island when compared with the large island? A The rate of immigration is lower for the small island than for the large island. B The small island has niches that are more like the mainland than the large island. C The small island has more available resources than the large island. D The rate of species extinction is lower on the small island than on the large island.

A

Based on the data in the table, if the number of snakes were to suddenly decrease, which of the following changes would most likely occur in the food web of this ecosystem? A increase in number of shrews decrease in number of hawks B increase in number of hawks decrease in number of shrews C increase in number of grasshoppers decrease in number of plants D increase in number of spiders decrease in number of plants

A

Based on the data shown in the graph, which of the following events occurred after the glacial retreat? A Primary succession B Flooding C Sea level rise D Global climate change

A

Based on the diagram above, which of the following processes reduces the amount of carbon dioxide in the atmosphere? A Photosynthesis B Cellular respiration C Decomposition D Burning of fossil fuels

A

Directions: Select the choice that best fits each statement. The following question(s) refer to the following energy efficiencies, expressed percentages. (A) 100% (B) 95% (C) 30% (D) 15% (E) 1% The maximum efficiency possible in an energy-conversion process that is not limited by the second law of thermodynamics A 100% B 95% C 30% D 15% E 1%

A

Directions: Select the choice that best fits each statement. The following questions(s) refer to the following elements. (A) Carbon (B) Sodium (C) Sulfur (D) Phosphorus (E) Potassium Marine sediments that form limestone are a major sink for this element. A Carbon B Sodium C Sulfur D Phosphorus E Potassium

A

Salamanders, ospreys, snapping turtles, and beavers all live in aquatic habitats. Salamanders lay their eggs in small freshwater pools and feed on insects. Osprey habitats include rivers, bays, and swamps and the birds feed on fish and other animals in the water or on land. Snapping turtles live in fresh or brackish water and feed on plants, fish, frogs, and snakes. Beavers build lodges on islands, pond banks, and lake shores and eat a variety of shrubs, grasses, and crops. Based on the information provided above, which of the following species would best be classified as a specialist? A Salamanders B Ospreys C Snapping turtles D Beavers

A

The data shown were collected in a laboratory experiment in which the effect of pH on the survival of water fleas (Daphnia pulex) was examined. In each trial, 40 live water fleas were added to a solution with the pH as indicated. After two hours, observations were made to determine the number of fleas remaining alive in the sample. Results are presented in the table and in graphical form above. How would including a control group be useful in this experiment? A It would provide a reference for the effects of random environmental factors. B It would provide a number against which percentages can be computed. C It would provide a value for which the standard pH can be measured. D It would provide a standard number to test for statistical uncertainty. E It would provide an end data point for graphical analysis.

A

The diagrams above show an area that was once a pasture that has since undergone changes to the vegetation over time. Which of the following changes in the hydrologic cycle is most likely to occur as a result of the change in vegetation in the area? A Increased infiltration B Increased runoff C Decreased transpiration D Decreased precipitation

A

The many finch species of the Galápagos Islands evolved from a single species that immigrated to the islands from the coast of South America. These species differ primarily in beak shape, which is closely related to the type of food each species specializes in eating. Which of the following best explains why each of the finch species on the Galápagos Islands evolved to be specialists? A Islands have limited food resources, forcing species to feed on a small range of food items. B Climate on islands tends to be less variable than on the mainland, minimizing seasonal absences of food. C Reduced competition from other bird species allows finch species to focus on specific food resources. D Food resources on islands are more plentiful and nutrient rich than on the mainland, leading to specialist behaviors in feeding.

A

Which of the following is a process that indirectly removes carbon from Earth's atmosphere? A Formation of carbonate deposits B Outgassing by volcanoes C Respiration by mammals D Respiration by anaerobic bacteria E Photodissociation by ultraviolet light

A

Which of the following is an example of a carbon sink? A Deposition of organic matter on the deep ocean floor B Clearing of trees in the Amazon forest C Combustion of fossil fuels in power plants D Decomposition of food waste by bacteria E Nutrient uptake by the roots of grasses in a suburban lawn

A

Of the following organisms, which occupies the lowest trophic level? A Spider B Deer C Lion D Hawk E Snake

B

Based on the data in the table, which ecosystem is in the earliest stages of succession? A Ecosystem A (7,6,5,5) B Ecosystem B (15,18,0,0) C Ecosystem C (3,3,6,16) D Ecosystem D (3,5,9,9)

B

Based on the diagram, which of the following reservoirs contains the most phosphorus? A Plants B Sediments C Soil D Oceans

B

Highly specialized species tend to evolve on islands because of the environmental conditions and resource availability. Based on the theory of island biogeography, which of the following would most likely experience the greatest decline of specialist species if an invasive species emigrated from the mainland? A A small island a far distance from the mainland B A small island in close proximity to the mainland C A large island a far distance from the mainland D A large island in close proximity to the mainland

B

In a given ecosystem, producers convert solar energy into 15,000kcal15,000kcal of chemical energy stored in organic compounds. Which of the following is the most likely amount of energy available to secondary consumers? A 1.5 kcal B 150 kcal C 1,500 kcal D 13,500 kcal

B

Of the following ecosystems, which has the lowest net primary productivity, measured as kilocalories of energy produced per square meter per year? A Taiga (boreal forest) B Open ocean C Temperature grassland D Estuary E Agricultural land

B

The feeding relationships between several marine organisms are shown in the food web below. Based on the diagram, which of the following best describes the most likely direct effect of a decline of the small fish population on the marine food web? A The jellyfish population will experience local extinction because of a lack of food resources. B The jellyfish population will increase because of decreased predation. C The jellyfish population will migrate to an area with more available habitat for eggs. D The jellyfish population will decrease from the increase in the sea turtle and tuna populations.

B

The next questions are based on the following table of organisms in an ecological community. The X in a cell indicates that the organism is eaten by the consumer in the first column. Based on the data in the table, which of the following pairs of organisms has two ecological relationships, both competition and predation? A Spiders and shrews B Hawks and snakes C Spiders and snakes D Spiders and grasshoppers

B

The process in the hydrologic cycle in which water vapor is released from leaves into the atmosphere is called A infiltration B transpiration C sublimation D reflection E percolation

B

Which letter correctly identifies a process of the hydrologic cycle in which the phase of water is changed from a liquid to a gas? A B C D

B

Which of the following best describes the movement of energy in an ecosystem? A Energy is constantly recycled by decomposers for use by producers. B Energy is harnessed by producers, and available energy decreases with each trophic level transfer. C Energy is absorbed by plants through water and soil and then moves up the food chain through consumers. D Energy is magnified as it moves up the trophic levels, and tertiary consumers store the most energy in a food web.

B

Which of the following would best describe X in the diagram above? A Bacteria play an important role in the conversion of compounds from the atmospheric gas to the form of the compound taken up by plants. B Phosphorus and nitrogen are both required for plant growth. C Volcanic eruptions are a major source of non-anthropogenic inputs. D Processes include weathering and erosion.

B

Based on the data shown in the graph, which of the following best describes how ecologists could determine when this ecosystem is approaching a climax community? A Determine if the keystone species in the ecosystem is present two years after the volcanic eruption B Measure the biomass of the pioneer species present before and after the volcanic eruption C Record the number and type of producers present every year after the eruption D Calculate the net primary productivity of a specific indicator species every year after the eruption

C

Based on the diagram above, which process most directly results in the storage of carbon as coal and oil over millions of years? A Photosynthesis B Cellular respiration C Decomposition D Burning of fossil fuels

C

For a primary producer, the main function of photosynthesis is to manufacture A oxygen B carbon dioxide C glucose D proteins E water

C

In the nitrogen cycle illustrated above, nitrification occurs in which of the following steps? A Step 1 B Step 2 C Step 3 D Step 4

C

Nitrogen FixationN2+3H2→2NH3N2+3H2→2NH3Nitrification2NH3+3O2→2NO2+2H2O+2H+2NH3+3O2→2NO2+2H2O+2H+Denitrification2NO3−+2CH2O+2H+→N2O+2CO2+3H2O2NO3−+2CH2O+2H+→N2O+2CO2+3H2O The table above shows the balanced chemical equations that represent three processes that are part of the nitrogen cycle. Which of the following is exemplified by the equations above? A Approximately 10%10% of energy is transferred from one trophic level to the next. B In a food web, energy flows and matter is cycled. C Each biogeochemical cycle demonstrates the conservation of matter. D The major reserve for nitrogen is in the atmosphere.

C

Photosynthesis is the major source of which of the following gases in Earth's atmosphere? A CO2 B H20 (water vapor) C O2 D H2 E N2

C

Raccoons eat a variety of foods and can live in a variety of habitats, including locations near humans. Tiger salamanders eat an abundance of worms and insects and require wetland habitats so they do not dry out. Which of the following best identifies the two different species? A Raccoons are decomposers, and tiger salamanders are scavengers. B Raccoons are carnivores, and tiger salamanders are herbivores. C Raccoons are generalists, and salamanders are specialists. D Raccoons have a Type II survivorship curve, and tiger salamanders have a Type I survivorship curve.

C

Scientists calculated the net primary productivity at two different forest sites. Both forests have the same gross primary productivity. Forest AA has a net primary productivity of 1,650kcal/m2/year1,650kcal/m2/year, and forest BB has a net primary productivity of 1,110kcal/m2/year1,110kcal/m2/year. Which of the following statements is best supported by the data? A Forest AA has a higher rate of decomposition by bacteria than forest BB. B Forest AA has more biodiversity than forest BB. C Forest AA producers have lower rates of cellular respiration than forest BB producers. D Forest AA producers have more biomass than forest BB producers.

C

The table above shows the balanced chemical equations that represent three processes that are part of the nitrogen cycle. Which of the following is exemplified by the equations above? A Approximately 10%10% of energy is transferred from one trophic level to the next. B In a food web, energy flows and matter is cycled. C Each biogeochemical cycle demonstrates the conservation of matter. D The major reserve for nitrogen is in the atmosphere.

C

Which of the following best describes the net primary productivity of an ecosystem? A Net primary productivity is the amount of energy captured by producers through photosynthesis over time. B Net primary productivity is the amount of energy lost by producers through respiration over time. C Net primary productivity is the amount of energy lost through respiration by producers subtracted from the gross primary productivity of an ecosystem. D Net primary productivity is the amount of energy lost through respiration by producers added to the gross primary productivity of an ecosystem.

C

Which of the following best explains how environmental stressors, such as wildfires, can affect biodiversity in an ecosystem? A After an environmental stress, a genetic bottleneck may occur, which will increase genetic diversity. B Habitat diversity will increase the available niches if the landscape becomes more uniform after a disturbance. C Ecosystems with more species diversity are more likely to recover after a disturbance than ecosystems with low species diversity. D Smaller populations are less likely to go extinct than larger populations, so the species diversity will remain constant.

C

Which of the following best explains why decomposers in soils and water are important to ecosystems? A They remove heavy metals. B They store carbon dioxide. C They recycle nutrients. D They neutralize acid deposition. E They produce more oxygen than they consume.

C

Which of the following best explains why terrestrial trophic pyramids usually do not have levels higher than tertiary consumers? A Tertiary consumers are the largest organisms in an ecosystem and require the most space to survive. B Plants can only perform photosynthesis during the day, so tertiary consumers cannot get enough energy from consuming plants. C A large proportion of energy is lost as heat as it is transferred up the pyramid, so there is not enough energy available to support another level. D Tertiary consumers are often indicator species and are the first to be affected by environmental disturbances.

C

Which of the following claims is best supported by the data in the graph? A The temperature of Earth rises and biodiversity increases immediately after a volcanic eruption. B The carrying capacity of plants in the area is approximately 250 species. C After the volcanic eruption, pioneer species colonized the area and the ecosystem began to undergo succession. D Plant species that are well adapted will survive and reproduce, leading to a change in the ecosystem biodiversity through the process of natural selection.

C

Which of the following elements is most likely to limit primary production in freshwater lakes? A Oxygen B Calcium C Phosphorus D Carbon E Iron

C

Which of the following is a measure of the biodiversity of an ecosystem? A The total number of individuals of a single animal species B The density of individuals in a hectare C The total number of different plant species D The soil depth at which burrowing insects are located

C

Which of the following is the best explanation for why there is such a small amount of phosphorus that moves into aquatic systems? A Phosphorus is highly stable in the atmosphere and remains there for long periods of time. B The amount of phosphorus in the cycle has been greatly reduced because of the use of catalytic converters in automobiles. C There is not a gaseous phase of the phosphorus cycle, and therefore the movement of phosphorus into oceanic reservoirs is very slow. D The phosphorus cycle occurs so rapidly that it does not exist in any one reservoir for a very long time.

C

Which of the following pathways indicate how nitrogen is added to the largest nitrogen reservoir? A Nitrifying bacteria and lightning B Decomposing plant and animal material C Denitrifying bacteria and volcanic activity D Nitrates taken up by plant roots

C

According to the diagram, the movement of phosphorus between biological organisms and soil is in a steady state in an undisturbed system. Which of the following best explains the reason for this steady movement? A Phosphorus is taken up by plants during photosynthesis to create carbohydrates. B A decrease in buffer zones prevents phosphorus runoff in waterways. C There is a rapid influx of phosphorus from the weathering of rocks. D Readily available organic phosphorus in the soil is assimilated by plants.

D

Directions: Select the choice that best fits each statement. The following questions(s) refer to the following elements. (A) Carbon (B) Sodium (C) Sulfur (D) Phosphorus (E) Potassium Guano from fish-eating birds is a commercial source of this element. A Carbon B Sodium C Sulfur D Phosphorus E Potassium

D

Elements that cycle in the environment and that also have a gaseous phase at some point in their cycle include which of the following? Carbon Phosphorus Sulfur A I only B III only C I and II only D I and III only E I, II, and III

D

Estuary provides refuge after dam removal for bull trout Bull trout use a bewildering array of strategies to aid in their survival, from remaining in streams their whole lives, like rainbow trout, to spending part of their lives in the ocean before returning to streams to spawn, just as salmon do. Bull trout are present in only one of two neighboring rivers in the Olympic peninsula, Washington state, and in this one (the Elwha River), where two large dams were removed. Dam removal resulted in massive outflow of sediments, reducing the clarity of the water and also building up a large delta and expanding the size of the estuary at the mouth of the Elwha River. Sampling for bull trout before, during, and after dam removal was used to detect whether bull trout changed their use of the Elwha River estuary or moved into the adjacent Salt Creek stream where they were formerly absent. Sampling revealed no movement into Salt Creek, but numbers of bull trout in the Elwha River estuary increased greatly during and immediately after dam removal, coinciding with large sediment outflow, before returning to their original low levels. Thus, bull trout appear to have used the enlarged estuary as a refuge from the effects of dam removal, then returning to the river when the river water cleared up from the sediment. Of additional interest is the long-term response of bull trout to the additional habitat opened up above the former dams. Lincoln, A. E., J. A. Shaffer, and T. P. Quinn. 2018. Opportunistic use of estuarine habitat by juvenile Bull Trout, Salvelinus confluentus, from the Elwha River before, during, and after dam removal. Environmental Biology of Fishes 101:1559-1569 Which of the following best identifies the author's claim? A Bull trout experienced high mortality rates as a result of the formation of the estuary and sediments released during dam deconstruction. B Bull trout are adaptable to a variety of habitats and were able to survive in the river habitat during the dam deconstruction. C Bull trout remained in the estuary system after the dam deconstruction because the disruption had irreversibly altered the river habitat. D Bull trout are unable to live in high sediment loaded waters and migrated to avoid the conditions introduced during dam deconstruction.

D

Small populations of animals, such as those typically found on islands, are prone to extinction because A they contain a high degree of genetic variability B they tend to have more predators C their habitats are more stable D they are more vulnerable to unpredictable events E they are usually generalist species

D

The diagram shows the amount of phosphorus measured in teragrams (1 teragram = 10^12 grams), in the various reservoirs of the phosphorus cycle. According to the diagram, the movement of phosphorus between biological organisms and soil is in a steady state in an undisturbed system. Which of the following best explains the reason for this steady movement? A Phosphorus is taken up by plants during photosynthesis to create carbohydrates. B A decrease in buffer zones prevents phosphorus runoff in waterways. C There is a rapid influx of phosphorus from the weathering of rocks. D Readily available organic phosphorus in the soil is assimilated by plants.

D

The major reservoirs of nitrogen and sulfur in the biosphere are correctly identified by which of the following? A Nitrogen: Rocks, Sulfur: Rocks B Nitrogen: Rocks, Sulfur: Vegetation C Nitrogen: Rocks, Sulfur: Atmosphere D Nitrogen: Atmosphere, Sulfur: Rocks E Nitrogen: Atmosphere, Sulfur: Atmosphere

D

The net primary production of a pine forest on a lava flow on Mount Fuji is about 175,000kcal/m2/yr175,000kcal/m2/yr, and the plant respiration is estimated to be 115,000kcal/m2/yr115,000kcal/m2/yr. What is the total amount of energy transferred during photosynthesis for this ecosystem? A 60,000kcal/m2/yr B 115,000kcal/m2/yr C 175,000kcal/m2/yr D 290,000kcal/m2/yr

D

Which letter correctly identifies the part of the hydrologic cycle that is most directly affected by impervious building materials, such as concrete and asphalt? A B C D

D

Which of the following best describes gross primary productivity in an ecosystem? A Gross primary productivity is the total amount of energy captured by producers plus the energy used by consumers over time. B Gross primary productivity is the total amount of energy captured by producers minus the energy that producers respire over time. C Gross primary productivity is the total amount of energy lost as heat during energy transfer between trophic levels. D Gross primary productivity is the total amount of solar energy captured by producers through photosynthesis over time.

D

Which of the following explanations is best supported by the data shown in the map above? A Earth's climate has changed over geological time, and plates on Earth's crust have shifted. B Sea level rise has led to an increased concentration of wildlife inland as the coastal areas flood. C Organisms adapt to human population growth by changing at the genetic level. D Animals migrate seasonally to mate and to find food in different habitats.

D

Which of the following major storage reservoirs of carbon, stored in the form of carbon dioxide, is not represented in this diagram? A Algae B Soil bacteria C The Moon D The ocean

D

Which of the following statements about levels of biodiversity is correct? A Genetic biodiversity is a measure of the total number of genes in a community. B A narrow distribution of habitats leads to an increase in species diversity. C Global hotspots are areas where species diversity is thriving due to habitat restoration. D A population with high genetic biodiversity is better able to respond to environmental stressors.

D

Which process in the nitrogen cycle releases nitrogen gas into the atmosphere? A Leaching of fertilizers from agricultural areas B Assimilation of soil nitrates by plants C Bacteria fixation of nitrogen in soil D Denitrification of soil nitrates by bacteria

D

Correct statements about the northern spotted owl include which of the following? It is a pioneer species that is an opportunistic feeder. It is dependent on mature, old-growth forest for its habitat. It is a carnivore at or near the top of the food chain. A I only B II only C III only D I and II E II and III

E

Directions: Each of the questions or incomplete statements below is followed by five suggested answers or completions. Select the one that is best in each case. A one-hectare pond is sampled in early September. The sample yields 1 small catfish as well as 17 benthic invertebrates that represent 10 species. If the pond is resampled a year later, which of the following would best indicate that the pond had been adversely affected by adjacent development? A An uncommon species has become more numerous. B An increase in low-tolerance species has occurred. C A decrease in high-tolerance species has occurred. D Phylogenetic diversity has increased. E The biodiversity of the pond has decreased.

E

Directions: Select the choice that best fits each statement. The following question(s) refer to the graph below which shows the monthly average CO2 concentration, in parts per million, as measured at Mauna Loa Observatory in Hawaii. Which of the following is most likely a significant cause of the general trend indicated by the graph? A Reduction of ozone concentrations in the upper atmosphere B Reduction in size of polar ice caps C Increase in energy output of the Sun D Increase in evaporation of ocean water E Increase in consumption of fossil fuels

E

The annual fluctuation in carbon dioxide concentration can best be explained by the A seasonal use of fossil fuels B regularity of volcanic activity C deforestation in the tropics D El Niño events E seasonal photosynthetic activity of green plants

E

The table below shows measurements of the beak size of a sample of ten ground finches on each of two islands in the Galápagos archipelago. The two islands are about ten kilometers apart, and all the birds are the same species. Given that beak size is genetically determined, which of the following hypotheses is the most likely explanation for the differences in data between the islands? A Egg mortality differs on the islands. B Beak size exerts selective pressure on prey size. C Birds on Daphne Island live longer than birds on Santa Cruz Island. D Large-beaked birds move to Santa Cruz Island and small-beaked birds move to Daphne Island. E The types of food found on the two islands exert selective pressure on beak size.

E

The ultimate source of energy for terrestrial ecosystem is A nutrients in soil B nutrients in vegetation C primary consumers D producers E the Sun

E