In the American Southwest, annually emerging cicadas are dependent upon the cottonwood trees in the floodplain. Adult male cicadas perch in the cottonwood trees and chirp to attract females. Females lay their eggs in the branches of the cottonwoods, and, upon hatching, the cicada nymphs drop to the ground, burrow into the soil, feed on the tree roots, and later emerge as adults. Other organisms in the floodplain community prey on the cicadas, as shown in the food web. Arrows extend from the cicada to a yellow billed cuckoo, a sparrow, a lizard, a wasp, a black widow, and a kestrel. An arrow extends from a cottonwood to the cicada. An arrow extends from a lizard to a kestrel. An arrow extends from a sparrow to a kestrel. An arrow extends from a yellow billed cuckoo to a kestrel. Figure 1. Food web in floodplain community Human activity has caused a decrease in the amount of flooding and an increase in the incidence of wildfires in the floodplain. In an investigation into the recent changes in the floodplain ecosystem, researchers monitored the soil temperature, amount of cottonwood ground coverage (i.e., area of the ground that is shaded by leaves), and cicada emergence for a period from mid-June until late July. The results of the investigation are represented in Figure 2 and Figure 3. The horizontal axis is labeled “Cottonwood Ground Coverage, in percent,” and the numbers O through 100, in increments of 20, are indicated. The vertical axis is labelled “Mean June Soil Temperature, in degrees Celsius,” and the numbers 18 through 28, in increments of 2, are indicated. The line of best fit is shown. The line begins at the point with coordinates 2 percent of cottonwood ground coverage comma 25 degrees Celsius and moves directly downward and to the right ending at the point with coordinates go percent cottonwood ground coverage and 19 degrees Celsius. Figure 2. Effect of cottonwood ground coverage on soil temperature The horizontal axis is labeled “Mean June Soil Temperature, in degrees Celsius,’ and the numbers 18 through 28, in increments of 2, are indicated. The vertical axis is labeled “Mean Emergence Date,’ and the dates 6 13 through 7 23, in increments of 5 days, are indicated. The line of best fit is shown. The line begins at the point with coordinates 19 degrees Celsius comma the date 7 21 and moves directly downward and to the right ending at the point with coordinates 26 point 5 degrees Celsius comma the date 6 13. Figure 3. Relationship between soil temperature and cicada emergence date To assess the impact of wildfires on soil temperature and cicada emergence, the researchers compared mean emergence dates for two natural sites where portions had been affected by wildfire. In addition, cicada emergence was monitored at an experimental site where the soil temperature was experimentally maintained. The data are shown in the table. MEAN CICADA EMERGENCE DATES AT SITES AFFECTED BY WILDFIRES OR WITH EXPERIMENTALLY CONTROLLED SOIL TEMPERATURE The table shows Mean cicada emergency dates for Natural Site 1, Natural Site 2, and Experimental Site. For Natural Site 1, the Mean Emergency Date for Unburned is July 8, and for Burned is June 18. For Natural Site 2, the Mean Emergency Date for Unburned is July 15, and for Burned is July 3. For Experimental Site, the Mean Emergency Date for 24 degree Celsius is July 14, and for 27 degree Celsius is July 5. Based upon the data, which of the following best describes the effect on the timing of cicada emergence if the cottonwood ground cover decreases from 50 percent to 25 percent?

Researchers studied the diversity of macroscopic invertebrates in different areas of watershed ecosystems. They collected samples from 58 sites along 11 streams in the same geographical area. Their data were classified by stream type and can be found in Figure 1. The stream-type classifications range from the perennial stream type, which always has water, to the intermittent stream type, which is dry for more than nine months during the year. The horizontal axis is labeled Stream Type, and the 4 bars indicated along it are labeled Perennial, Transitional, Seasonal, and Intermittent respectively. An error range is given for each bar. The vertical axis is labeled Simpson’s Diversity Index, and the numbers 0 through 0.45, in increments of 0.05, are indicated. Each bar is described as follows. Note that all values are approximate. Perennial. 0.40, plus or minus 0.02. Transitional. 0.34, plus or minus 0.5. Seasonal. 0.39, plus or minus 0.2. Intermittent. 0.32, plus or minus 0.4. Figure 1. Diversity of macroscopic invertebrates in different stream types. Error bars represent a 95% confidence interval (±two Standard Errors from the mean). Which of the stream types had a statistically lower macroscopic invertebrate species diversity than the seasonal streams?

The specimens are arranged in three rows that read: Bottom Row: Mussels, Giant Tubeworms, and Shrimp. Middle Row: Zoarcid Fish and Dandelion Siphonophores. Top Row: Octopuses and Blind Crabs. In the bottom row, there is one arrow from Mussels to Octopuses; there is one arrow from Giant Tubeworms to Zoarcid Fish; and there are three arrows from Shrimp to Zoarcid Fish, Dandelion Siphonophores, and Blind Crabs. In the middle row, there is one arrow from Zoarcid Fish to Octopuses; and there is one arrow from Dandelion Siphonophores to Blind Crabs. In the top row, there is one horizontal arrow from Blind Crabs to Octopuses. The food web above represents feeding relationships in a biological community near a deep-sea hydrothermal vent. Hydrothermal vents are geysers on the seafloor that gush super-heated, mineral-rich water. The seawater surrounding hydrothermal vents typically contains carbon dioxide (CO2), molecular hydrogen (H2), hydrogen sulfide (H2S), and methane (CH4). Sunlight, however, fails to reach the seafloor where deep-sea hydrothermal vents are located. As part of an investigation, researchers collected living specimens from an area near a deep-sea hydrothermal vent. Mussels in the collection were found to be dependent on molecular hydrogen in seawater. Also, the researchers discovered multiple species of bacteria living in the gills of the mussels. Mussels use gills for filter-feeding and gas exchange with the surrounding seawater. On the basis of their experimental results, the researchers hypothesized that some bacteria living in the gills of the mussels are capable of chemosynthesis. To refine their model of deep-sea biological communities, the researchers investigated areas of the seafloor that are distant from any active hydrothermal vents. Which of the following is the best interpretation of the observation that some octopus species are only found near active hydrothermal vents?

Populations of organisms have the potential to increase at exponential rates, yet most population growth fits a logistic model of growth. Why is this?

The diagram below shows a simple food web.   At the bottom of the diagram is a box labeled “Grass.” From the grass box, three arrows point upward to three boxes arranged horizontally in the middle level: “Rabbits” on the left, “Mice” in the center, and “Squirrels” on the right. From each of these three boxes, arrows point upward and converge on a single box at the top labeled “Foxes.” The arrows indicate that grass is consumed by rabbits, mice, and squirrels, and that all three of these herbivores are consumed by foxes. Which group of organisms is expected to have the highest overall productivity?

When two species are in competition for the same resource, which of the following is not a likely outcome?

______ is a process in which organisms rapidly diversify into a variety of new forms. This happens particularly when environmental changes make new resources available, such as a mass extinction event.

Percent of Moths Recaptured in Two Different Environments Trial Moth Color and Environment Percent of Released Moths Recaptured I Light-colored moths were released in an unpolluted environment. 13% II Light-colored moths were released in a polluted environment. 12% III Dark-colored moths were released in an unpolluted environment. 7% IV Dark-colored moths were released in a polluted environment. 28% A researcher released large numbers of moths into different environments in an attempt to better understand a mechanism of evolution. The moths were released in four trials as described in the table above. Each of the released moths had a small mark on the underside of a wing for identification. After an appropriate amount of time, the researcher recaptured as many of the released moths as possible. Data from the experiment are included in the table above. Which of the following claims is best supported by the data?

A moth’s color is controlled by two alleles, G and g, at a single locus. G (gray) is dominant to g (white). A large population of moths was studied, and the frequency of the G allele in the population over time was documented, as shown in the figure below. In 1980 a random sample of 2,000 pupae was collected and moths were allowed to emerge. Each figure shows an image of a stickleback fish with a genetic structure below it. The left figure is labeled Figure 1. Marine stickleback. A long Pelvic Spine on the fish is labeled. The genetic structure below the fish contains three enhancers, a promoter, and a gene. From left to right, the Enhancer Sequences are labeled Hindlimb, Pituitary, and Jaw. To the right of the Enhancer Sequences is a Promoter with an arrow moving up and to the right, over the top of the Pitx1 gene. The right figure is labeled Figure 2. Freshwater stickleback. A short Pelvic Spine on the fish is labeled. The genetic structure below the fish contains three enhancers, a promoter, and a gene. From left to right, the Enhancer Sequences are labeled Hindlimb, Pituitary, and Jaw. The Hindlimb enhancer is crossed out with an X, and it is labeled Disabled Due to Mutation. To the right of the Enhancer Sequences is a Promoter with an arrow moving up and to the right, over the top of the Pitx1 gene. Assuming that the population was in Hardy-Weinberg equilibrium for the G locus, what percentage of moths in the natural population was white in 1962?

Simpsons Diversity Index is a way to quantify the diversity of a community.  The equation can be written as: D = N(N-1) / ∑ n ( n– 1)  Where: D = Diversity index N = Total number of individuals of all species n = Number of individuals of a specific species   Community A has 3 species (A, B, C). There are 5 individuals of each species. (N=15) Community B has 6 species (A, B, C, D, E). There are 3 individuals each of species A, B, and C. There are 2 individuals each of species D, E, and F. (N=15) Community C has 5 species (A, B, C, D, E). There are 3 individuals each of species. (N=15)   What is the species diversity of Community C?