topics 2.4-2.7 Flashcards
Little is known about Africa’s elusive aardvarks, but new research says they are vulnerable to climate change like many other species.
Hotter temperatures are taking their toll on the aardvark, whose diet of ants and termites is becoming scarcer in some areas because of reduced rainfall.
Drought in the Kalahari Desert killed five out of six aardvarks that were being monitored for a year, as well as 11 others in the area.
The aardvarks’ body temperatures plummeted during the night because they were not getting enough energy from diminished food sources. They tried to conserve energy by looking for insects during the warmer daytime, but their efforts to adapt could not save them.
Researchers said some birds, reptiles and other animals use aardvark burrows to escape extreme temperatures, reproduce, and hide from predators. They could have fewer refuges available if aardvark populations shrink because of rising temperatures, they said.
The aardvark, which lives in many parts of sub-Saharan Africa, is identified as an animal of “least concern” on an international “red list” of threatened species. There are no indications that the population is changing significantly in southern Africa, though it is speculated that numbers may be declining elsewhere because of habitat destruction, the bushmeat trade and other factors.
“Study Finds aardvarks suffering as African climate heats up,” Christopher Torchia, Phys.org, July 31, 2017.
Which of the following best identifies the author’s claim?
a. Aardvarks are shifting the location of their territories as a response to global climate change.
b. Aardvarks are a keystone species and their decline could have a trophic cascade effect on the ecosystem.
c. The loss of aardvarks described in the study was an isolated incident because most aardvark populations are increasing globally.
d. Providing aardvarks with more burrows will help them maintain their body temperature and increase survival rates.
b. Aardvarks are a keystone species and their decline could have a trophic cascade effect on the ecosystem.
Living organisms must acquire energy from their environment. Examples of adaptations that help organisms acquire this energy include which of the following?
I. The dark, heat-absorbing coloration of a reptile.
II. The fangs and claws of a lion
III. The light coloration of a peppered moth
a. I only
b. II only
c. I and II only
d. II and III only
e. I, II, and III
c. I and II only
Which of the following was the average beak size of finches on the island of Daphne Major in 1976?
a. 8.8 mm
b. 9.5 mm
c. 10.2 mm
d. 13.8 mm
b. 9.5 mm
Which of the following statements best explains the changes in the size and composition of the population of finches after the drought?
a. The total number of finches in the population increased, and the smaller-beaked finches were more successful in the drier environment.
b. The total number of finches in the population increased, and the larger-beaked finches were more successful in the drier environment.
c. The total number of finches in the population decreased, and the smaller-beaked finches were more successful in the drier environment.
d. The total number of finches in the population decreased, and the larger-beaked finches were more successful in the drier environment.
d. The total number of finches in the population decreased, and the larger-beaked finches were more successful in the drier environment.
Which of the following was the number of finches in the population with a beak size of 10.2 mm in 1978?
a. 8
b. 12
c. 40
d. 65
b. 12
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. Bull trout are unable to live in high sediment loaded waters and migrated to avoid the conditions introduced during dam deconstruction.
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. Record the number and type of producers present every year after the eruption
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. After the volcanic eruption, pioneer species colonized the area and the ecosystem began to undergo succession.
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. It would provide a reference for the effects of random environmental factors.
On the basis of the data, the best prediction of the pH of the water in which Daphnia normally are found in the wild is
a. 1
b. 3
c. 5
d. 7
e. 9
d. 7
The pH at which 50 percent of the Daphnia survive after 2 hours of exposure can be predicted from the data. This pH is closest to
a. 2.5
b. 3.5
c. 4.5
d. 7.5
e. 8.5
c. 4.5
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 types of food found on the two islands exert selective pressure on beak size.
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. primary succession
Scientists at the National Oceanic and Atmospheric Administration
(
NOAA
)
are forecasting this summer’s Gulf of Mexico hypoxic zone or “dead zone”—an area of low to no oxygen that can kill fish and other marine life—to be approximately
7
,829
square miles, or roughly the size of Massachusetts. The annual prediction is based on United States Geological Survey river flow and nutrient data.
The 2019 forecast is close to the record size of
8
,776
square miles set in 2017 and larger than the five-year average measured size of
5
,770
square miles.
The annually recurring Gulf of Mexico hypoxic zone is primarily caused by excess nutrient pollution from human activities, such as urbanization and agriculture, occurring throughout the Mississippi River watershed. Once the excess nutrients reach the gulf, they stimulate an overgrowth of algae, which eventually die, then sink and decompose in the water. The resulting low oxygen levels near the bottom are insufficient to support most marine life and have long-term impacts on living marine resources that are unable to leave the area.
A major factor contributing to the large dead zone this year is the high amount of spring rainfall in many parts of he Mississippi River watershed, which led to record high river flows and much larger nutrient loading to the Gulf of Mexico. This past May, discharge in the Mississippi and Atchafalaya rivers was about
67
percent above the long-term average between 1980 and 2018. The latest National Climate Assessment predicts an increase in the frequency of very heavy precipitation events in the Midwest, Great Plains, and Southeast regions, which would impact nutrient input to the northern Gulf of Mexico and the size of the hypoxic zone.”
News release adapted from the United States Geological Survey
Which of the following best identifies the author’s claim?
a. The increased size of the hypoxic zone in the Gulf of Mexico is forecasted to benefit the fishing industry in the United States.
b. The increased rainfall events in the United States are decreasing the tolerance of fish and other marine species in the Gulf of Mexico because of a decreased concentration of oxygen.
c. Many marine species are migrating away from the Gulf of Mexico as a result of increased nutrient pollution from increased rainfall events.
d. The large hypoxic zone in the Gulf of Mexico is directly linked to climate change in the Mississippi River watershed.
b. The increased rainfall events in the United States are decreasing the tolerance of fish and other marine species in the Gulf of Mexico because of a decreased concentration of oxygen.
A North Carolina timber company proposes to clear-cut 45 hectares of oak-hickory deciduous forest in the Appalachian Mountains. The company has said that the forest will regrow naturally, and 50 years after the clear-cutting the company plans to harvest again, cutting all the oaks and hickories that have at least a 40-centimeter diameter. A local citizens’ group claims that this is not a realistic plan. Which of the following, if true, best supports the claim of the citizens’ group?
a. Harvesting oak and hickory will disrupt the soil in the first year after clear-cutting; oaks and hickories cannot germinate that first year.
b. Oak and hickory are late-successional species; pioneer species will dominate for many decades before the oaks and hickories are reestablished.
c. Coniferous forests can regrow after having been clear-cut; the biome will change to a boreal forest after clear-cutting.
d. Populations of large carnivores in the forest will decline after clear-cutting occurs; deer hunting will suffer as a result.
e. Erosion rates on the slopes of the Appalachian Mountains will decrease after clear-cutting; many new species will move into the forest.
b. Oak and hickory are late-successional species; pioneer species will dominate for many decades before the oaks and hickories are reestablished.
