Section Exam #5 Ecology, 252 exam 4, Exam 1 252, Biology 252 - Midterm #3, BIOL 252 - Exam 2

The Lotka-Volterra predator-prey model of population growth does not depend on the availability of the predator's resources. is independent on the prey's resources. does not change when the predator population declines. assumes that when predators are absent the prey population grows exponentially.

assumes that when predators are absent the prey population grows exponentially.

The map is of an imaginary planet that is roughly the same as Earth. Like Earth, it is tilted on its axis by about 23°, and it rotates around a sun-like star in approximately one year. Which site would mostly likely have the greatest variation in temperature during the year? Site D Site C Site B Site A

site D

Some slow-growing trees have leaves that are high in lignin. The most likely advantage of lignin to such trees is that lignin has high concentrations of phosphorus, which is necessary for slow-growing trees. slows the rate of decomposition, thereby lowering the fertility of the soil and allowing the trees to outcompete plants with high growth rates. has a low C:N ratio, and thus it enriches the soil in its immediate vicinity. kills certain microorganisms that are needed for plants with high growth rates, protecting the trees from competitive exclusion.

slows the rate of decomposition, thereby lowering the fertility of the soil and allowing the trees to outcompete plants with high growth rates.

Leaves that are comparatively _______ and _______ lose the most heat to wind because they have _______ boundary layers than other leaves. large; rough; thinner small; smooth; thinner small; smooth; thicker large; rough; thicker

small; smooth; thinner

Suppose that the mean residence time of nitrogen in a section of soil is 3.5 years, and the mean rate of input is 150 kilograms per year. If rates of input and output as well as the total pool size have remained roughly constant, what is the expected size of the total pool of nitrogen in that soil? 525 kg 150 kg 1,050 kg 300 kg

525kg

Individuals of a plant species are counted in five transects that are each 2 × 2 meters. In these transects, 8, 15, 19, 27, and 31 plants are found. What is the density per square meter of this species? 15 5 10 20

5

The highest rates of NPP in the ocean occur around _______ North and South because this is where _______ most common. 10°; upwelling is 50°; upwelling is 10°; Hadley cells are 50°; Hadley cells are

50°; upwelling is

The competitive exclusion principle states that the _______ species prevents another species from using essential resources, causing the _______ species to become locally extinct. smaller; larger larger; smaller inferior; dominant dominant; inferior

dominant; inferior

According to the basic host-pathogen model, if the combined death and recovery rate from a disease doubles, and the effectiveness of the disease to spread from infected to uninfected individuals remains the same, the threshold density should double. decrease by a factor of four. stay the same. decrease by half.

double.

At which stage of succession is facilitation usually the most significant factor? Late Middle Early Facilitation is equally important in middle and late stages.

early

Which organisms can only be found in the photic zone of any aquatic ecosystem? Larger animals, like fish Zooplankton Fungi phytoplankton

phytoplankton

Chemical energy derived from the fixation of carbon by photosynthesis and chemosynthesis is known as _______ production. gross secondary net primary

primary

Which type of succession involves colonization of habitats devoid of life? Pristine Primary Secondary Abiotic

primary

The figure shows examples of possible disturbance intensity (y-axis) and frequency (x-axis) combinations. What type of succession occurs after the disturbance in A? Primary succession Little succession occurs Climax Secondary succession

primary succession

Four species of fish in a pond are found in equal abundance. The Shannon index of the fish community is therefore 0.25 (ln 0.25). 1 [4 (ln 4)]. 4 [0.25 (ln 0.25)]. 0.25 [0.25 (ln 4)].

−4 [0.25 (ln 0.25)].

Suppose that the osmotic potential of a system is −45 MPa. Pressure of 60 MPa is being exerted on the system and the matric potential is −40 MPa. What is the overall water potential of the system? −65 MPa −25 MPa −145 MPa +55 MPa

-25MPa

What is the Shannon index value for an area in which only a single species is present? Infinity 1 0 -1

0

The transmission coefficient of the hypothetical disease Dirks fever is 0.8. If the combined death and recovery rate is 0.4, what is the threshold density for Dirks fever? 4 0.8 0.5 0.32

0.5

If a cow with an assimilation efficiency of 10% and a production efficiency of 20% eats 50 kg of grass, the expected increase in biomass of the cow would be 1 kg. 500 g. 200 g. 10 kg.

1 kg

Based on the figure, extinction was a possible outcome for _______ breeding pairs. 10,000 1,000 10 100

1,000

Mushroom-feeding Drosophila species, including the species D. neotestacea, D. falleni, D. putrida, and D. recens, are prevalent in the Great Lakes region of the United States. Suppose a biologist collects flies from three different communities and obtains the results shown in the tables. What is the Shannon index of community 1? 1.094 1.191 6.519 1.000

1.191

If there are 100 plants in a population in year 1, and 120 plants in the population in year 2, what is λ? 1.2 12 0.12 120

1.2

A continuously growing population of bears has a population size of 500 and its intrinsic rate of increase is r = 0.07 per year. Assuming that this rate of increase remains the same, about how long should it take for the population to reach 1,000? (Note: The natural logarithm of 2 is about 0.70.) 5 years 14 years 20 years 10 years

10 years

Suppose that the net primary productivity of a particular ecosystem is 80 units per year. The respiration rate of primary producers is 30 units per year, and the respiration rate of herbivores is 10 units per year. The gross primary productivity is _______ units per year. 110 40 70 50

110

A plant requires a minimum of 50 mm of precipitation per month to grow. Its water requirements increase with increasing temperature, such that for every 1°C that the average monthly temperature is above freezing, it requires an additional 1 mm of precipitation. Based on the climate diagram, and assuming the weather reflects long-term climatic averages, this plant should be able to grow during how many months of the year? 9 11 6 12

12

Suppose the trophic efficiency between producers and herbivores is 0.1, the tropic efficiency between herbivores and carnivores is 0.15, and primary production is 1,200 units per day. What is the secondary production of herbivores? 18 units per day 1,200 units per day 120 units per day 90 units per day

120 units per day

Suppose that the NEE of a boreal forest ecosystem is 120 units per month. The respiration by autotrophs is 60 units per month, and the respiration by heterotrophs is 30 units per month. What is the NPP of the forest? 60 units per month 90 units per month 150units per month 210 units per month

150 units per life

A mouse is sitting in the sun. Solar radiation provides a net intake of energy of 30 milliwatts per minute, and infrared radiation provides an additional net input of 8 milliwatts per minute. Conductive and convective outputs are a combined 55 milliwatts per minute. There is no detectable change in heat from evaporation. Assuming that the mouse is maintaining a constant temperature, how much heat must it be generating per minute? 25 milliwatts 17 milliwatts 33 milliwatts 38 milliwatts

17 milliwatts

In accordance with Wilson and MacArthur's theory of island biogeography, the following equations represent the immigration and extinction rates of species of beetles on a small island. (I = immigration rate of species per month; E = extinction rate of species per month; S = number of species currently on the island.) I = 9 - 0.2S E = 0.3S Based on these equations, what is the expected equilibrium species diversity on that island? 5 10 24 18

18

Suppose the trophic efficiency between producers and herbivores is 0.1, the tropic efficiency between herbivores and carnivores is 0.15, and primary production is 1,200 units per day. What is the secondary production of carnivores? 60 units per day 12 units per day 120 units per day 18 units per day

18 units per day

Suppose that the net secondary production in a community is 530 kilograms. The respiration of heterotrophs is 1,400 kilograms, and the egestion is 350 kilograms. Plant respiration is 2,700 kilograms. How much plant material did the heterotrophs ingest? 2,280 kilograms 880 kilograms 1,930 kilograms 530 kilograms

2,280 kilograms

A population of Drosophila melanogaster with 10,000 individuals and a carrying capacity of 20,000 follows the logistic growth equation. Suppose that 5,000 individuals of a competitor species, Drosophila simulans, are added to the population, and that this species has an α of 0.5. One would predict that this number of competitive individuals will decrease the D. melanogaster population growth rate by the same amount as the addition of _______ D. melanogaster individuals would. 250 750 1,000 2,500

2,500

What type of growth does this population appear to be showing? Negative Exponential Logistic Cycling

exponential

Suppose that the NEE of a boreal forest ecosystem is 120 units per month. The respiration by autotrophs is 60 units per month, and the respiration by heterotrophs is 30 units per month. What is the GPP of the forest? 150 units per month 210 units per month 60 units per month 90 units per month

210 units per life

If the population density of ocotillo in a desert is 15 per square kilometer, how many plants would be expected in an area that is 5 km × 3 km? 1,500 225 45 15

225

Suppose that rabbits are the only prey and food supply of foxes, and that the predator-prey interaction follows Lotka-Volterra dynamics. The mortality rate of foxes in the absence of rabbits is 0.1 per week, and the intrinsic growth rate of rabbits in the absence of predation is 0.2 per week. The capture efficiency is 0.002, and the efficiency at which rabbit biomass is converted into fox biomass is 0.2. If there are 30 foxes in a population, and 400 rabbits are present, the rate at which prey will be killed is _______ per week. 24 30 80 120

24

Suppose that heterotrophs ingested 1,560 kilograms of plant biomass over a month's period. Respiration of these heterotrophs was the equivalent of 900 kilograms, and they egested 420 kilograms. What is the net secondary production? 900 kilograms 240 kilograms 1,560 kilograms 660 kilograms

240 kilograms

If the NPP of an ecosystem is 240 units per year, and the respiration by autotrophs is 110 units, what is the amount of energy available for increases in plant biomass? 110 units per year 130 units per year 240 units per year 350 units per year

240 units per year

A population of white oak trees with 500 individuals and a carrying capacity of 1,500 follows logistic growth. Under ideal low-density conditions, its growth rate is 0.15 per year, but it faces competition from a population of 1,000 Chapman oaks with an α of 0.5. What is the expected growth of the population of white oaks in the next year? 0 25 50 75

25

A population of Drosophila mauritiana reproduces in synchrony at discrete time periods every generation, and generations occur at two-week intervals. The current population size is 1,000, and its geometric population growth rate is 3.0 per generation. What will the expected size of the population be after six weeks? 3,000 27,000 9,000 81,000

27,000

Based on the data in the figure, what is the carrying capacity in this environment? 10 5 28 39

28

Based on the data in the figure, what is the carrying capacity in this environment? 28 10 5 39

28

A population of rabbits reproduces in synchrony at discrete time periods each year. If the current population is 150 and its geometric population growth rate is 1.4 per year, the expected size of the population after two years will be 294. 210. 140. 196.

294

The transmission coefficient of the hypothetical disease Dumas fever is 0.3. If the combined death and recovery rate is 0.9, what is the threshold density for Dumas fever? 1.2 0.3 3 28

3

An entomology research team interested in controlling the spread of winter moths, an insect pest in the northeastern United States, samples a 150-square-meter patch of woodland with four quadrats of 1 meter by 1 meter each. In quadrats A, B, C, and D, respectively, 10, 20, 35, and 15 individual winter moths are found. What is the best estimate for the total number of winter moths in that patch of woodland? 8,000 3,000 2,000 80

3,000

A population of turtles contained 342 individuals at the end of the year 2013. Since then, 44 have died, 37 were born, 17 immigrated, and 6 emigrated. What is the population size now? 298 385 346 335

346

The pH of a sample of water that had 10 times the concentration of H+ ions as a sample with a pH of 5.8 would be 3.8. 4.8. 6.8. 15.8.

4.8

Estimates show that oceans absorb about _______ of all the atmospheric CO2. 40% 10% 48% 1%

48%

Suppose that growing a plant requires at least 60 mm of precipitation and mean monthly temperatures between 5°C and 30°C. Based on the climate diagram, and assuming that the weather conforms to the long-term average, the plant should be able to grow during how many months of the year? 4 12 6 10

6

Drosophila sechellia often eat Indian mulberry plants. Suppose the consumption efficiency of Drosophila is 20%, the assimilation efficiency is 40%, and the production efficiency is 30%. If Drosophila eat 50 kilograms of the plant, how much will be used to produce fly biomass? 4.8 kg 1.2 kg 2.4 kg 6 kg

6 kg

What would be the mean residence time of phosphorus in a pond if the total pool is 1,250 grams and the mean rate of input is 2,500 grams? (Assume that rates of input, output, and the total pool size have remained constant.) 18 months 6 months 2 years 1 year

6 months

In a population of three asexual lizards, each lizard has a 40% probability of not producing any offspring. What is the probability that all three lizards will produce no offspring, thus ensuring the population's extinction? 1% 6.4% 83.4% 21.6%

6.4%

Suppose that net secondary production in an ecosystem is only 15% of the total amount of plant material ingested by heterotrophs. If herbivores egest 20% of what they ingest, what percentage of what they ingest goes to heterotroph respiration? 65% 35% 80% 20%

65%

A population of rodents contained 703 individuals at the end of March. During the month of April, 47 died, 17 were born, 57 immigrated, and 16 emigrated. What was the population size after those events? 714 730 692 673

714

The atmosphere is composed of _______% nitrogen in the form of _______. 21; NH4+ 78; NH4+ 21; N2 78; N2

78; N2

If the GPP of an aquatic ecosystem is 180 units per year, and the NPP is 100 units, what is the respiration rate of the primary producers? 80 units per year 180 units per year 100 units per year 260 units per year

80 unites per year

Tuna often eat sardines and other small fish. Suppose the consumption efficiency of tuna is 40%, the assimilation efficiency is 30%, and the production efficiency is 20%. If tuna eat 1,500 kg of sardines and other small fish, how much will be used to produce tuna biomass? 36 kg 180 kg 90 kg 120 kg

90 kg

Suppose that heterotrophs ingested 7,500 kilograms of plant biomass over a month's period. Respiration of these heterotrophs was the equivalent of 5,200 kilograms, and they egested 1,400 kilograms. What was the net secondary production? 1,400 kilograms 400 kilograms 900 kilograms 2,300 kilograms

900 kilograms

From the act of pollinating flowers, a bee population gains the benefit of a 0.06 growth rate increase per month. However, the costs imposed by the flower (bees occasionally getting stuck, time spent pollinating the flower instead of pollinating other species, etc.) is a 0.02 reduction in growth rate per month. The flower gains benefits from the pollination that enhance its population growth rate by 0.05 per month, but it incurs costs (feeding the bees, damage done by the bees) that reduce its growth rate by 0.05 per month. In this situation, what is the best description of the relationship between the bees and the flowers? A mutualism A commensalism A host-parasite relationship An amensalism

A commensalism

Suppose you are studying a population of herbivores. The traditional food source for these herbivores is a small native plant species. In the last 200 years, the traditional food source of these herbivores was replaced by an invasive grass. The herbivores gained 5 calories of food from every 1 minute of grazing on the native plant, but gain only 3 calories of food from every 1 minute of grazing on the invasive grass. If you compared the current population of herbivores to the historical populations 200 years ago, which change would you be least likely to observe? A decrease in the overall length of the digestive tract An increase in bacterial symbionts associated with digestion An increase in coprophagy An increased ability to acclimatize to different food sources

A decrease in the overall length of the digestive tract

All other factors being equal, which scenario is least likely to involve coevolution? An obligate positive interaction in which the two parties are closely related A facultative interaction in which the two parties are from different kingdoms An obligate positive interaction in which the two parties are from different kingdoms An obligate positive interaction in which one party lives inside the other

A facultative interaction in which the two parties are from different kingdoms

Which statement about food webs is false? A food web can be a useful tool for understanding potential impacts invasive species have on native species when they are introduced into an ecosystem. A food web is a dynamic model describing all species interactions under all environmental conditions. Food webs that try to outline every species interaction are difficult to construct and often become "spaghetti diagrams." A food chain (an overly simplified food web) is often too simplified to be useful in studying the impact a species has in an ecosystem.

A food web is a dynamic model describing all species interactions under all environmental conditions.

Which of the following would likely have the greatest proportion of productivity going into its own respiration? A short evergreen tree in New England A large tree in the Brazilian tropical rainforest A flower in the Brazilian tropical rainforest A bunch of ferns in Canada

A large tree in the Brazilian tropical rainforest

A continuously growing population of alligators has a population size of 1,000 and an intrinsic rate of increase of r = 0.05 per year. Assuming that this rate of increase remains the same, about how long should it take for the population to grow larger than 4,000 individuals? (Note: The natural logarithm of 2 is about 0.70.) A little more than 7 years Less than 4 years About 14 years A little more than 27 years

A little more than 27 years

In the simple host-pathogen model, which term describes the rate at which a susceptible individual encounters an infected individual? SI S dI βSI

SI

Which population would be expected to remain stable in size? A population with a λ of 0 and an r of 1 A population with a λ of 1 or an r of 0 A population with an r of > 0 A population with an r of < 1

A population with a λ of 1 or an r of 0

Which population is likely to be increasing in size? A population with a λ of 0 A population with a λ of 0.98 A population with a λ of 1.3 A population with an r of −0.04

A population with a λ of 1.3

Croll et al. studied the effects that long-term inhabitation of artic foxes had on the ecosystems of the Aleutian Islands. Based on their findings, which of the following statements is true? Accumulation of guano on the island was not influenced by the introduction and long-term inhabitation of artic foxes. The nitrogen content in the seabirds' guano increased in response to predation. A reduction in the quantity of guano released on the islands inhabited by artic foxes resulted in an ecological shift from grasslands to more shrubs and forbs. Croll et al. concluded that while artic foxes reduced the number of seabirds on the islands, they did not cause the alteration of island ecosystems where they lived.

A reduction in the quantity of guano released on the islands inhabited by artic foxes resulted in an ecological shift from grasslands to more shrubs and forbs.

In desert environments, many larger plants serve as "nurse" plants for smaller species that grow beneath them and benefit from their shade. Which characteristic of this association suggests that coevolution is not a major factor? The association occurs only in the desert. The association involves commensalism, rather than mutualism. A single nurse species can protect many different smaller species. The association is facultative, rather than obligate.

A single nurse species can protect many different smaller species.

Assuming that their average population growth rates and all other factors are equal, which population would most likely be at risk for extinction? A large population with low variation in its growth rate A large population with high variation in its growth rate A small population with high variation in its growth rate A small population with low variation in its growth rate

A small population with high variation in its growth rate

Suppose you wanted to determine whether you had adequately sampled the species richness of a given community. Which result would lead most strongly to the conclusion that the current sampling had adequately assessed the species diversity? A linear species accumulation curve A low Shannon index value A high Shannon index value A species accumulation curve that leveled off

A species accumulation curve that leveled off

Which species will most likely exhibit a regular or nearly regular pattern of dispersion? A species whose habitat is patchily distributed A species that competes for a limiting resource that is equally distributed in space A species with short dispersal distances A species in which individuals are positioned at locations selected at random

A species that competes for a limiting resource that is equally distributed in space

Which of the following is most likely to prevent or stop an arms race between host and parasite? A trade-off between a host's survival in the absence of parasitism and its reproductive success in the absence of parasitism The absence of a trade-off between the host's survival and reproduction when parasitized A trade-off between a host's survival when parasitized and its reproductive success in the absence of parasitism Rare genotypes of the host that make the host less resistant to parasitism

A trade-off between a host's survival when parasitized and its reproductive success in the absence of parasitism

In which environment is transpiration likely to make the greatest contributor to the cooling of a leaf? A hot desert at noon on a cloudy day during a summer drought A tundra grassland at noon during the winter A boreal forest at noon on the coldest day during the winter A tropical rainforest at noon on a sunny day

A tropical rainforest at noon on a sunny day

When heterotrophs consume food (organic compounds), they convert it to usable chemical energy, primarily in the form of _______, during the process of _______. ATP; the Calvin cycle sugar; the Calvin cycle sugar; glycolysis ATP; glycolysis

ATP; glycolysis

The figure shows the relationship between the ambient temperature and the relative metabolic rates of a number of mammals. What is the lower critical temperature of an unclothed human? About 20°C About 11°C About 6°C About 26°C

About 26°C

Which of the following would be considered a community stress? Predation by a new predator A beaver population that is causing trees to fall A fire that destroys half of the trees in an area Correct! Acidity in the water that is limiting the reproduction of certain fish species

Acidity in the water that is limiting the reproduction of certain fish species

Suppose you are wanting to study a tropical rainforest community. You choose to use a guild subset to study this community. Which of the following would be appropriate as this subset? All bird species in the rainforest All nitrogen fixing plants in the rainforest All granivores in the rainforest All canopy trees in the rainforest

All granivores in the rainforest

Which statement about endoparasites is true? All parasites living in the alimentary canal are endoparasites. All endoparasites have simple lifecycles that take place within a single host. All endoparasites are microparasites. All endoparasites that infect animals are parasites of the alimentary canal.

All parasites living in the alimentary canal are endoparasites.

Which statement is true? All symbionts are mutualists. All symbionts are parasites. All parasites are pathogens. All pathogens are parasites.

All pathogens are parasites.

Three examples of associations in nature include: 1) Sea anemones riding on the backs of hermit crabs where the two species protect each other from their different enemies; 2) Lactobacillus bacteria living inside the human gut, having a beneficial effect on human health; and 3) Leaf-cutting ants farming and feeding on specific fungi, which receive free food and protection. How can these three associations best be classified? All three are symbioses. All three are commensalisms. Associations 1 and 3 are commensalisms; association 2 is a symbiosis. Associations 1 and 3 are symbioses; association 2 is a commensalism.

All three are symbioses.

Of the four temperature curves in the two populations, which combination appears least able to acclimate to the given temperature regime? Desert population at the 23°C day/18°C night regime Coastal population at the 23°C day/18°C night regime Desert population at the 43°C day/30°C night regime e Coastal population at the 43°C day/30°C night regime

Coastal population at the 43°C day/30°C night regime

Which of the following is not an example of a resource? A stenocara beetle captures water from fog that condenses on its back An increase in temperature increases aggressiveness in a species of coral reef fish. Dung beetles collect and store dung to be used as a food source for their larva A bumblebee collects nectar from a flowering plant

An increase in temperature increases aggressiveness in a species of coral reef fish.

Which of these organisms would be considered a true autotroph? A mistletoe that receives energy from both photosynthesis and its host plant A dodder that pierces into the phloem of its host plant to obtain nutrients An oak tree that receives all of its energy through photosynthesis A sea slug that obtains nutrients from the algae it feeds on

An oak tree that receives all of its energy through photosynthesis

According to measurements taken in the 1990s, the levels of inorganic nitrogen in Arctic ecosystems were substantially lower than the amount of nitrogen actually taken up by plants. Which of the following is a possible explanation for this pattern? Arctic trees are able to perform nitrogen fixation with enzymes in their leaves. Arctic sedges can take up organic forms of nitrogen. Microbes in the Arctic soil transform inorganic nitrogen into organic forms. Arctic shrubs take up 60% of their nitrogen in the form of N2.

Arctic sedges can take up organic forms of nitrogen.

The figure shows the relationship between the outside temperature and the temperature of three animals. Which of these animals is an endotherm? Animal C only Animal B only Both animal A and animal B Animal A only

Animal A only

Which of the following could not be a hemiparasite? Any ectoparasite Any macroparasite Any microparasite Any heterotroph

Any heterotroph

Which statement about ecotypes is true? Ecotypes are populations with adaptations to unique environments. An ecotype is always able to acclimate to severe cold weather. Ecotypes are a response to abiotic factors only. Ecotypes can never become separate species.

Ecotypes are populations with adaptations to unique environments.

In their work on aspen-fir interactions, Calder and St. Clair claim that aspens are facilitated by the presence of fir trees. From these data, what is the primary evidence for aspen being facilitated by fir? Aspen mortality decreases when they are within 0.5 m of a fir tree. Aspen mortality increases when they are within 0.5 m of a fir tree. Aspen mortality is highest in fir-dominated stands. Fir mortality is highest when at distances greater than 0.5 m from aspen.

Aspen mortality decreases when they are within 0.5 m of a fir tree.

Which statement about the equilibrium model of island biogeography is false? At equilibrium, the species composition of an island will not change. The model applies to island-like habitats (hospitable habitat patches surrounded by inhospitable habitat) as well as literal islands. If the extinction rate increases, the number of species on an island should decrease. If the immigration rate increases, the number of species on an island should increase.

At equilibrium, the species composition of an island will not change.

Which plant is most effective in photosynthesizing at tissue temperatures of 30°C? Ambrosia Tidestromia Neuropogon Atriplex

Atriplex

Which position would best represent the equilibrium point for species diversity on a large island far from the mainland? A D C B

B

Which of the following statements about climate is false? Climate controls where organisms live, their geographic distribution, and how they function. Climate can vary over time. Climate is a short-term description of outdoor conditions that we experience daily. There can be seasonal variation in climate.

Climate is a short-term description of outdoor conditions that we experience daily.

Which statement about the nutrient supply in marine ecosystems is false? -Benthic zones contain a mixture of ocean-derived detritus and terrestrial sediments. -Because of the lack of oxygen, decomposition does not occur in marine ecosystems. -As freshwater mixes with saltwater, the change in pH and other chemical changes can release phosphorus bound to soil particles. -Rates of nitrogen fixation are lower in marine ecosystems than in lakes.

Because of the lack of oxygen, decomposition does not occur in marine ecosystems.

Which statement about oceanic currents is false? Oceanic currents can have profound effects on the climates of regions where they flow. Because they move so slowly, oceanic currents contribute little to the exchange of heat between the tropics and the polar regions. Deep oceanic currents meet surface currents at zones of upwelling. Dense downwelling currents move to the equator.

Because they move so slowly, oceanic currents contribute little to the exchange of heat between the tropics and the polar regions.

In which sequence are the organisms' expected production efficiencies correctly ranked from highest to lowest? YBeetle > mouse > fox Mouse > fox > beetle Fox > mouse > beetle Beetle > fox > mouse

Beetle > fox > mouse

Organisms in the ocean that live on detritus are most likely to live in which zone, shown in the figure? Photic zone Nearshore Benthic zone Shallow ocean

Benthic zone

invertebrates that consume detritus would most likely be found in which zone of the river ecosystem? Benthic zone Main channel Hyporheic zone Riparian zone

Benthic zone

The birth and death rates of a population of garter snakes were monitored over 11 years, during which time population density varied considerably. According to the figure, which statement about the populations is true? Density-independent factors are regulating population size. Birth rates equal death rates. Birth rate declines at high population sizes. At high population sizes, the death rate is higher than it is at low population sizes.

Birth rate declines at high population sizes.

Which ecosystems have the slowest turnover rates of elements (the greatest mean residence times)? Chaparrals with low amounts of moisture in the soil Boreal forests with large nutrient pools and low rates of litter input Tropical forests with small nutrient pools and high rates of litter input Temperate coniferous forests with low levels of nitrates in the soil

Boreal forests with large nutrient pools and low rates of litter input

A large plant that grows in a warm, swampy environment and faces substantial herbivory most likely has a much larger than usual difference between its GPP and its NPP. Both a and c allocates a relatively large proportion of its NPP to secondary compounds. allocates a relatively large proportion of its NPP to roots.

Both a and c

The cells of a fish are about 0.85% salt. One liter of water is about 1,000 grams. Solution A contains 70 grams of salt in 5 liters of water, solution B contains 120 grams of salt in 10 liters of water, and solution C contains 50 grams of salt in 10 liters of water. Which solution(s) is(are) hyperosmotic relative to the fish's cells? Both solution B and solution C Solution A only Solution B only Both solution A and solution B

Both solution A and solution B

Suppose you are studying two small lakes (lake 1 and lake 2) and how they change over time. A nearby farm accidentally spills fertilizer into lake 1. Around the same time, a non-native fish-eating turtle is introduced into lake 2. The ecosystems of both lakes are affected by these changes. What processes most likely explain how the lakes were affected? Bottom-up control in lake 1; top-down control in lake 2 Bottom-up control in both lakes Top-down control in both lakes Top-down control in lake 1; bottom-up control in lake 2

Bottom-up control in lake 1; top-down control in lake 2

In which way can a parasite change an ecological community? By forming a symbiotic relationship with the dominant competitor, causing the abundances of other species to stay the same By not contributing to altering the physical environment in the area By not changing the outcome of species interactions By altering the composition of ecological communities

By altering the composition of ecological communities

Which of the following is not an observed pattern of population growth observed in nature? Population cycling Exponential growth Logistic growth Infinite population growth

exponential growth

What takes place during the second step of photosynthesis, referred to as the "carbon reactions"? Chlorophyll is oxidized by water. CO2 is oxidized by solar radiation. CO2 is fixed, producing carbohydrates. Water is split to provide electrons to synthesize ATP and NADPH

CO2 is fixed, producing carbohydrates.

Based on the figure, the best explanation for the relationship of CO2 uptake and O2 concentration is that CO2 uptake becomes negative by 100% O2 concentration at both CO2 levels. CO2 uptake decreases with increasing O2 concentration at both CO2 levels. CO2 uptake increases with increasing O2 concentration at both CO2 levels. CO2 uptake becomes negative by 100% O2 concentration at high CO2 levels.

CO2 uptake decreases with increasing O2 concentration at both CO2 levels.

In the CAM pathway, in contrast to pathways in C3 and C4 plants, CO2 uptake and the Calvin cycle are separated in time, with CO2 uptake occurring at night and the Calvin cycle during the day. both CO2 uptake and the Calvin cycle occurring during the day. both CO2 uptake and the Calvin cycle occurring at night. CO2 uptake occurring during the day and the Calvin cycle at night.

CO2 uptake occurring at night and the Calvin cycle during the day.

Plants with bacterial symbionts that fix _______ are often important players in _______ stages of succession. phosphorus; late sulfur; early phosphorus; early nitrogen; early

nitrogen; early

Two similar rodent species are consistently more different from each other when they occupy the same habitat than when they live separately. What is the most likely explanation for the increased divergence when they live together? Decreased resource partitioning Character displacement Competitive exclusion Intraspecific competition

Character displacement

Two species of Drosophila have been competing in the lab for a long time. A researcher notes that over the course of time, the competition coefficients of these species have become smaller. What is the most likely explanation of this change? Periodic disturbances Allelopathy Character displacement Competitive exclusion

Character displacement

Based on the figure, which group or groups of pigments absorb visible light primarily in the red and orange part of the spectrum? Carotenoids only Chlorophyll a and carotenoids Chlorophyll a only Chlorophyll a and chlorophyll b

Chlorophyll a and chlorophyll b

Which principle is best supported by the results of Sutherland's studies in which fish predators were excluded from a marine fouling community? Facilitation is most important in early succession, whereas inhibition becomes more important in later stages. Predation is a relatively unimportant factor in succession in marine c communities. Communities can follow different successional paths and display alternative states. In most marine systems, the tolerance model accurately predicts successional outcomes.

Communities can follow different successional paths and display alternative states.

Mushroom-feeding Drosophila species, including the species D. neotestacea, D. falleni, D. putrida, and D. recens, are prevalent in the Great Lakes region of the United States. Suppose a biologist collects flies from three different communities and obtains the results shown in the tables. Based on the Shannon index, rank the species diversity from highest to lowest. Community 1 > Community 3 > Community 2 Community 1 > Community 2 > Community 3 Community 3 > Community 2 > Community 1 Community 2 > Community 1 > Community 3

Community 1 > Community 2 > Community 3

Which statement accurately describes the portfolio effect? -Ecosystem stability creates a positive indirect effect on herbivores. -The greater the biomass of an ecosystem the less likely it is to be altered by disturbances. -Community stability is enhanced when the population of one species cancels out variation in another such that the overall abundance in the community remains the same. -Community biodiversity does not alter the net effect of predators in a diverse population.

Community stability is enhanced when the population of one species cancels out variation in another such that the overall abundance in the community remains the same.

Suppose that two species of rabbits inhabit an area. Which technique would provide estimates of their relative population densities, as opposed to estimates of their absolute densities? Quadrat sampling Mark-release studies Comparisons of the number of tracks made by each species Comparisons of area counts

Comparisons of the number of tracks made by each species

Which statement about competition is false? Exploitation competition is the most common form of competition in nature. Competition is often symmetrical. Tilman's study of diatoms competing for silica provides an example of exploitative competition. Two gulls fighting over a piece of fish is a form of exploitation competition.

Competition is often symmetrical.

Which statement about atmospheric circulation patterns is false? Air cools due to expansion as it rises in the troposphere. Cool air can hold more water vapor than warm air can. The condensation of water vapor into clouds is a warming process. Thunderclouds potentially reach only to the boundary between the upper region of the troposphere and the bottom of the stratosphere.

Cool air can hold more water vapor than warm air can.

A mycorrhizal&ndsah;associated fungus grows between the cells of the root of a plant, forming a mantle around the exterior of the root. This is an example of which type of association? Endomycorrhizal Arbuscular mycorrhizal Communalistic mycorrhizal Ectomycorrhizal

Ectomycorrhizal

Which statement about density-independent factors is true? Food and habitat availability are density-independent factors that influence population size. Density-independent factors increase the size of populations when population size is low. Density-independent factors decrease the size of populations when population size is high. Davidson and Andrewartha's studies of thrips (Thrips imaginis) showed that density-independent factors play a major role in the annual fluctuations of abundance of this species.

Davidson and Andrewartha's studies of thrips (Thrips imaginis) showed that density-independent factors play a major role in the annual fluctuations of abundance of this species.

Scientists have studied the value of positive interactions in ecosystems by measuring the "relative neighbor effect" (RNE), or the effect that neighboring species have on the growth of a target species. Given the usual purposes of positive interactions, in which ecosystem would the neighboring plant species be most likely to help a target species? Prairie Deciduous forest Desert Rainforest

Desert

The table shows the number of species of a group of mammals present in the tropics, the subtropics, and the temperate zone over the last fifty million years. Of the three broad categories of hypotheses that have been proposed to explain latitudinal gradients (diversification rate, diversification time, and productivity or carrying capacity), these data most clearly fit which hypothesis? Diversification time Carrying capacity Combination of diversification rate and diversification time Diversification rate

Diversification time

You are in Glacier Bay. Starting at a location dominated by alders, you would most likely first run into the _______ stage if you travelled toward the glacier's edge and the _______ stage if you travelled away from the glacier's edge. pioneer; spruce Dryas; spruce pioneer; Dryas spruce; Dryas

Dryas; spruce

Which of the following is an advantage that endoparasites have over ectoparasites? Less susceptibility to the host's immune system Ease of feeding A simpler life cycle Dispersal ability

Ease of feeding

Which of the following is a finding of the Biological Dynamics of Forest Fragments Project (BDFFP)? Similar numbers of species were retained in a single 1,000 hectare forest fragment as in ten 100 hectare forest fragments. Edge effects were common and led to increases in local species extinctions. The largest fragments maintained all of their previous species diversity. Edge effects were a significant issue only in the largest forest fragments since smaller fragments had very little edge due to their small size.

Edge effects were common and led to increases in local species extinctions.

The equilibrium theory of island biogeography was developed by Alfred Russel Wallace and Charles Darwin. Edward O. Wilson and Robert MacArthur. Alfred Russel Wallace and Edward O. Wilson. Daniel Simberlof and Frances James.

Edward O. Wilson and Robert MacArthur.

Which type of heat transfer is much more common in plants than in animals? Output of infrared radiation Evaporative heat loss Reception of solar radiation Metabolic heat generation

Evaporative heat loss

Two species of birds feed on berries. The birds are active at different times of the day and do not come into contact with one another. Nonetheless, the presence of one species limits the survival and reproduction of the other. What type of competition is this? Interference Exploitation Allelopathy Logistic

Exploitation

Which trophic level generates the most dead organic material in most ecosystems? First Third Second Fourth

First

King's Lomatia (Lomatia tasmanica) is a most unusual plant. In the wild, only a single genetic individual of this shrub is known to be alive, and this colony has existed for at least 40,000 years. When a branch of this shrub falls to the ground, it sometimes establishes roots, and thus can function as a physiologically independent plant that is genetically identical to all other plants in the colony. What is the technical term for the single genetic individual? Genet Biotic Ramet Gamete

Genet

Which statement about polar bears is true? Geographic distribution of polar bears is limited to the Artic because they cannot pass through warm tropical regions. Polar bears' geographic distribution follows their preferred food source of penguins. The evolutionary distribution of polar bears shows they once lived in Antarctica. Continental drift can explain how polar bears migrated from Antarctica to the Artic.

Geographic distribution of polar bears is limited to the Artic because they cannot pass through warm tropical regions

Which statement about the influence of evolutionary and geologic history on species distribution and abundance is true? Geological history influences distribution of suitable habitat and thus influences where an organism exists today. Evolutionary history can only influence the abundance of a population if the species evolved within the last 10,000 years. Evolutionary history cannot influence where an organism exists today. Geological history cannot influence dispersal of populations.

Geological history influences distribution of suitable habitat and thus influences where an organism exists today.

A student is asked to determine which species of green crab they have found based on the predator avoidance response index. After three independent trials, the average predator avoidance response index was determined to be 12. Which species has the student been studying? Littorina littorea Gibbula cineraria Osilinus lineatus Gibbula umbilicalis

Gibbula cineraria

Which of these is the best example of acclimatization to light variation that is accomplished by morphological, rather than physiological means? Golden banner plants adapt to varying light conditions by adjusting their number of chloroplasts and the thickness of their leaves. e Plants in different climates have different forms of the same photosynthetic enzymes, according to which form operates best in the plant's particular environment. Unlike other plants, lichens in the Arctic can photosynthesize at temperatures close to freezing. Spearscale plants grown in different light environments vary in maximum net photosynthesis rate, nighttime respiration values, and light compensation points.

Golden banner plants adapt to varying light conditions by adjusting their number of chloroplasts and the thickness of their leaves.

The total amount of photosynthesis is referred to as gross photosynthetic production (GPP). net photosynthetic production (NPP). gross primary production (GPP). net primary production (NPP).

Gross primary production (GPP)

The country of Guatemala is currently experiencing rapid population growth, Greece is experiencing essentially zero population growth, and Germany is experiencing negative population growth. Assuming that age-specific fecundities are similar in these three countries, which of the following is most likely? Greece should have the highest proportion of young individuals. Germany should have the highest proportion of young individuals. Guatemala should have the lowest proportion of young individuals. Guatemala should have the highest proportion of young individuals.

Guatemala should have the highest proportion of young individuals.

A fungus increases the ability of a plant to grow under high-salt conditions. For the plant, this association is which type of mutualism? Habitat Formic Trophic Chemical

Habitat

Which of the following can cause the population of a previously nondispersed species to develop a metapopulation structure? Habitat fragmentation Demographic stochasticity Genetic drift Environmental stochasticity

Habitat Fragmentation

What is the name of the circulation pattern indicated by the black arrow? Polar cell Hadley cell Ferrell cell Dobson cell

Hadley cell

Which of the following is not a difference between herbivores and carnivores? Carnivores kill their prey, while herbivores do not. Animal prey can be hard to find, while plants are not. Animal prey is much less nutritious than plant prey. Herbivores typically eat only a small part of the plant and carnivores eat the whole animal.

Herbivores typically eat only a small part of the plant and carnivores eat the whole animal.

A population at the zero population growth isocline is increasing in size via exponential growth. stable in size. decreasing in size. increasing in size via logistic growth.

stable in size.

Which statement about keystone species is false? Keystone species tend to be predators at higher trophic levels, but are not restricted to this group. The keystone species concept implies that protecting the keystone species may also help protect the species that depend on it. Keystone species have larger effects on community composition than would be predicted based on their biomass or abundance. If a species acts as a keystone species in one part of its range, it must act as such in all parts of its range.

If a species acts as a keystone species in one part of its range, it must act as such in all parts of its range.

The Anopheles mosquito, which causes malaria, requires warm temperatures to complete the life cycle of Plasmodium falciparum. Which of the following statements is true? If temperatures decrease due to climate change, it is hypothesized that the incidences of malaria will shift toward the poles. If temperatures decrease due to climate change, it is hypothesized that the incidences of malaria in humans and wildlife will increase. If temperatures increase due to climate change, it is hypothesized that the incidences of malaria in humans and wildlife will increase. If temperatures increase due to climate change, it is hypothesized that the incidences of malaria in humans and wildlife will decrease.

If temperatures increase due to climate change, it is hypothesized that the incidences of malaria in humans and wildlife will increase.

Which principle is illustrated by Lande's theoretical work with spotted owls? Introducing a small population of competitors helps keep metapopulations connected. Metapopulations do not vary based on suitable habitat. Delay of abiotic shuffling can cause population cycles. If the availability of suitable habitat for a species goes below a critical threshold, the entire metapopulation will collapse.

If the availability of suitable habitat for a species goes below a critical threshold, the entire metapopulation will collapse.

As a budding scientist you discover a parasite associated with your favorite organism. To learn more about the parasite and the organism, you study them in depth, learning that the organism attacks the parasite using memory cells in an effort to prevent infection. Which type of mechanism is the organism utilizing as a defense against the parasite? Gene counterdefense Immune system Biochemical defense Defensive symbiont

Immune system

Which statement about the difference between a competitive network and a competitive hierarchy is true? in a competitive hierarchy, one species dominates the interaction; in an interaction network, no one species dominates the interaction. The interactions are stronger in a competitive network than in interaction networks. In a competitive hierarchy, indirect species interactions always buffer strong competition; in interaction networks, they do not. A competitive network comprises more species than interaction networks.

In a competitive hierarchy, one species dominates the interaction; in an interaction network, no one species dominates the interaction.

Which of the following should reduce the critical threshold for the spread of disease? Decreasing the transmission of coefficient β Decreasing the rate at which individuals become immune Increasing the rate at which individuals die Increasing the density of susceptible individuals

Increasing the rate at which individuals die

Which statement about radiant energy from the sun is false? It is converted directly to chemical energy in plants. It is responsible for most of the warmth of our atmosphere. It is the original source for the fuel we use in our cars and homes. It can be converted directly to chemical energy by heterotrophs.

It can be converted directly to chemical energy by heterotrophs.

How does the nutrient cycle of aquatic systems differ from that of terrestrial systems? -Nitrogen cycles are less important in aquatic ecosystems. -Inputs of nutrients from outside the ecosystems are more important in aquatic ecosystems. -Chemical weathering does not contribute to nutrient supply in aquatic ecosystems. -Aquatic ecosystems are not dependent on decomposition.

Inputs of nutrients from outside the ecosystems are more important in aquatic ecosystems.

What is the primary difference between interaction webs and food webs? Interaction webs do not consider primary producers, where food webs do. interaction webs include more trophic levels. Interaction webs include fewer trophic levels. Interaction webs include non-trophic interactions, where food webs do not.

Interaction webs include non-trophic interactions, where food webs do not.

Two species of birds actively fight over berries. Injuries have been observed, and the presence of one species limits the survival and reproduction of the other. What type of competition is this? Interference Exploitation Allelopathy Logistic

Interference

What is not an explanation for coexistence of species that use the same set of limiting resources? Environmental variation Periodic disturbance Periodic fire Intraspecies competition

Intraspecies competition

The figure shows bird species richness for islands of different sizes that are close to New Guinea, far from New Guinea, or intermediate in distance from New Guinea. Based on this figure, which of the following statements is false? Islands closer to New Guinea tend to have more bird species than islands that are farther away. islands that are large but far from New Guinea are likely to have the most bird species. Larger islands tend to have more species of birds, independent of distance from New Guinea. For a given island size, near islands tend to have more bird species than far islands.

Islands that are large but far from New Guinea are likely to have the most bird species.

Which negative effect can habitat fragmentation have on a metapopulation? It can make patches smaller, thus increasing the patch extinction rate. It can make patches more connected, thus increasing the patch colonization rate. It can lead to dampened oscillations within patches. It can isolate predators, preventing them from preying on the species of interest.

It can make patches smaller, thus increasing the patch extinction rate.

Which statement about nitrogen fixation is false? It is energetically expensive. It is more common in late succession than in early succession.Legumes are examples of plants that use nitrogen-fixing bacteria. It often results in trade-offs in growth and/or reproduction

It is more common in late succession than in early succession.

NPP is generally lower at 25° latitude than it is 10° closer to the equator or 10° closer to the poles. What is the best explanation for this phenomenon? This latitude corresponds with high concentrations of upwelling zones. Decomposition rates are particularly high at this latitude. Descending Hadley cells disrupt the ability of plants to acquire carbon dioxide. It is much drier at this latitude.

It is much drier at this latitude.

Which statement about parasite natural history is false? It is rare for a host species to have a parasite that feeds upon only that species. Many species are host to more than one parasite species. Different parts of human bodies provide suitable habitat for a wide range of parasites. Both large and small parasites typically feed on one or a few host individuals.

It is rare for a host species to have a parasite that feeds upon only that species.

Which of the following statements about effective population size is true? It is the maximum number of individuals an ecosystem can support. It is the number of individuals needed to maximize genetic diversity. It is the number of individuals that can contribute offspring to the next generation. It is the minimum number of organisms needed for a population to survive.

It is the number of individuals that can contribute offspring to the next generation.

How does the protein transferrin assist in defenses against parasites? It removes iron from the blood serum in vertebrate hosts and stores it in intracellular compartments. It is used in encapsulating parasite eggs. It allows "memory cells" of the immune system to store information about pathogens, thus providing lifelong immunity. It paralyzes nematode parasites.

It removes iron from the blood serum in vertebrate hosts and stores it in intracellular compartments.

Which statement about the second law of thermodynamics is true? It states that as energy is transferred, some energy remains with the original trophic level. It predicts that trophic biomass pyramids can never be inverted. It states that some energy will be lost in any transfer of energy. It states that entropy tends to decrease during energy transfers.

It states that some energy will be lost in any transfer of energy.

Which statement about the Pacific Decadal Oscillation (PDO) is false? It is an oscillation of sea surface temperature and atmospheric pressure. Evidence that it has occurred over many centuries has been gathered from tree ring data. Its cycles typically do not last as long as those of ENSO and other similar oscillations. It is a major driver of salmon populations in the Pacific.

Its cycles typically do not last as long as those of ENSO and other similar oscillations.

According to the climate diagram, the highest temperatures and the most precipitation at this location occur during which months, respectively? January; January July; July April; January January; July

January; January

When you touch something hot, your hand becomes warm; this is an example of the transfer of which type of energy? Kinetic Chemical Autotrophic Radiant

Kinetic

In comparing exponential and geometric growth, which statement is true? The multiplier r can be calculated from λ, and is equivalent to "e" raised to the λ power. Lambda (λ) can be calculated from r and is equivalent to the natural logarithm of r. The multiplier r is not used in estimating exponential or geometric growth. Lambda (λ) can be calculated from r and is equivalent to "e" raised to the r power.

Lambda (λ) can be calculated from r and is equivalent to "e" raised to the r power.

Which statement about the condition known as pubescence is false? Light-colored hairs increase the effectiveness of latent heat transfer. Pubescence results in a trade-off between two opposing heat exchange mechanisms. Light-colored hairs decrease the effectiveness of convective heat loss. Light-colored hairs lower absorption of solar radiation by the leaf surface.

Light-colored hairs increase the effectiveness of latent heat transfer.

In Farrell's (1991) work on algal succession, the presence of limpets had what effect on the growth of algae? The role of limpets depends on the presence or absence of Balanus. Limpets facilitate algal succession. Limpets tolerate algal succession. Limpets inhibit algal succession.

Limpets inhibit algal succession.

Which of the following is the primary factor limiting the distribution of saguaro cacti in Arizona? Low temperatures Precipitation High temperatures Herbivores

Low Temperatures

Which statement comparing island biogeography to mainland biogeography is true? On the mainland, extinction rate increases with area faster than immigration rate does, whereas the opposite is true for islands. Mainland sites should experience higher rates of immigration than island sites. The slope of species richness to area should be steeper for mainland species than for island species. Mainland sites should experience higher rates of extinction than island sites.

Mainland sites should experience higher rates of immigration than island sites.

_______ is the seasonal roundtrip movement of populations. Migration Disturbance Habitat dispersal Dispersal limitation

Migration

Huge numbers of adult periodic cicadas emerge simultaneously from pupae at intervals of either 13 or 17 years. This phenomenon is most similar to which of the following? Masting Compensation Induced defense Aposematism

Masting

Based on the climate diagram, precipitation is usually the highest in November and December March and April. January and February May and June.

May and June.

Which statement best describes the relationship between mechanical and chemical weathering? Chemical weathering impedes mechanical weathering. Chemical weathering promotes mechanical weathering. Mechanical weathering impedes chemical weathering. Mechanical weathering promotes chemical weathering.

Mechanical weathering promotes chemical weathering.

Which characteristic is an advantage that ectoparasites have over endoparasites? They can feed easier. They are less exposed to predators. They can more easily disperse to other hosts. They are less exposed to changes in the external environment.

They can more easily disperse to other hosts.

Which organism is an example of a hemiparasite? Plasmodium Mistletoe Head louse Live fluke

Mistletoe

Which statement about global biogeographic patterns is true? Broad species diversity patterns are better explained by differences in longitude than differences in latitude. Most groups of organisms show more diversity at the tropics than at higher latitudes. All groups of organisms show more diversity at the tropics than at higher latitudes. For any given latitude, the diversity of species is roughly constant for all longitudes.

Most groups of organisms show more diversity at the tropics than at higher latitudes.

In some regions where two tectonic plates meet, one plate forces the other plate downward. Such areas are called drift zones. subduction zones. faults. ridges.

subduction zones

Which statement about populations is false? Population abundances change over time and space. Most organisms have similar capacities for dispersal. If little is known about the distance that sexually reproducing organisms or their gametes move, the area that constitutes a single population is difficult to estimate. A population may consist of a series of patches of individuals that are isolated in space but are connected by dispersal.

Most organisms have similar capacities for dispersal.

How does predation and herbivory differ from parasitism and parasitoidism? Parasitism and parasitoidism are not exploitative relationships. Most parasites and parasitoids spend their entire lives consuming a single individual, whereas herbivores and predators usually eat at least several different individuals. Unlike parasitoids and parasites, predators and herbivores usually do not exert strong selective pressures on their food organisms. Parasitism never results in the death of the organism, while predation and herbivory usually do cause the death of the organisms they eat.

Most parasites and parasitoids spend their entire lives consuming a single individual, whereas herbivores and predators usually eat at least several different individuals.

Which sequence represents the correct ranking (from highest to lowest) of the metabolic rates of a 35-gram mouse, a 150-gram ectothermic lizard, and a 20-kg dog? Mouse > lizard > dog Mouse > dog > lizard Lizard > dog > mouse Dog > mouse > lizard

Mouse > dog > lizard

The figure shows the RNE (relative neighbor effect) correlated to summer temperatures in alpine plants. Higher summer temperatures indicate communities at lower elevations, where plants are less stressed. The RNE is one measurement of the degree of mutualism in a community—the higher the RNE, the stronger the mutualistic interaction. Based on the data in this figure, which conclusion can be drawn about the importance of mutualism in this community? Mutualism becomes stronger under more stressful conditions. Mutualism becomes stronger under less stressful conditions. Mutualism is relatively unimportant among alpine plants. Mutualism becomes stronger at lower temperatures, but stress is not a factor.

Mutualism becomes stronger under more stressful conditions.

In a plant-pollinator interaction, the plant expends energy to produce colors and scents that attract the pollinator. This energy is therefore not available to use in the plant's growth and reproduction. This interaction provides evidence in favor of which statement? Partners join mutualisms for altruistic reasons. Both partners benefit equally from the relationship. Mutualisms may impose costs on the partners. Conflicts of interest seldom exist in mutualisms.

Mutualisms may impose costs on the partners.

Which statement correctly describes the role of nitrogen fixation in the nutrient cycle? N2 is inhaled by herbivores and transformed into ammonia, which can be dissolved in their blood. NH4+ is converted by certain bacteria into complex proteins that can then be ingested by animals. N2 is taken in by green plants and transformed into nitrogen-rich protein. N2 is taken up by certain bacteria that can change it into chemically available forms usable by plants.

N2 is taken up by certain bacteria that can change it into chemically available forms usable by plants.

Suppose that the aboveground biomass of a section of a grassland ecosystem is 400 kilograms at the start of the growing system. A month later, it is 1,600 kilograms. During that month, the _______ is _______ kilograms. NPP; 1,200 NPP; 400 GPP; 1,200 GPP; 400

NPP; 1,200

In their classic test of the equilibrium theory of island biogeography, Simberloff & Wilson removed arthropods from a set of small mangrove islands, then tracked the recovery of the arthropod fauna on these islands through time. Which of the following can be inferred from the figure? Prior to the experimental removal of arthropods, species richness was higher on far islands than on near islands. Species richness was highest on islands that were both larger and closer than the other islands. By the end of the experiment, species richness was higher on far islands than on near islands. Near islands recovered their original species richness before far islands did.

Near islands recovered their original species richness before far islands did

Which statement about studies on the importance of competition in nature is false? Nearly all studies find the occurrence of competition; competition is ubiquitous in nature. Many studies find the occurrence of competition; competition is common in nature. Analyses of the studies identified several possible sources of bias, including the failure of researchers to publish studies that show no significant results. Many studies were biased because they overly represented species that were suspected to show competition.

Nearly all studies find the occurrence of competition; competition is ubiquitous in nature.

Which statement about net secondary production is false? In most terrestrial ecosystems, net secondary production is a small fraction of NPP. In most terrestrial ecosystems, the lowest percentage of net secondary production is associated with detritivores. As a percentage of NPP, net secondary production is usually higher in terrestrial ecosystems than in aquatic ecosystems. Net secondary production depends on the digestibility and nutrient content of the heterotrophs' food.

Net secondary production depends on the digestibility and nutrient content of the heterotrophs' food.

Of nitrogen and phosphorus, which is the most limiting nutrient to primary production early in primary succession, and why? Nitrogen, because it undergoes chemical reactions with the phosphorus Phosphorus, because it undergoes occlusion over time Nitrogen, because it takes a long time to accumulate in the soil through decomposition You Answered Phosphorus, because it is very soluble and is easily leeched from the soil

Nitrogen, because it takes a long time to accumulate in the soil through decomposition

If the temperature of a plant is 18°C and the ambient temperature is 14°C, which process will result in a net input of heat from the air to the plant? Evaporation Convection None of the above Conduction

None of the above

Members of the same functional group must belong to the same None of the above guild. trophic level. taxonomic group.

None of the above

Population cycles in all small rodents are driven by? None of the above; no universal cause of population cycles in small rodents has been identified. competitors. predators. parasites.

None of the above; no universal cause of population cycles in small rodents has been identified.

In bottom-up control, energy flow through the ecosystem is determined primarily by the abundance of carnivores. production efficiencies of herbivores. supply of resources limiting NPP. assimilation efficiencies of herbivores

upply of resources limiting NPP.

Which statement about enslaver parasites is false? Only invertebrates have been enslaved by parasites. Enslaver parasites manipulate their hosts in order to further their transmission to the next host. The manipulation of cricket behavior by hairworms reduces the survival of parasitized crickets. Several fungi species can alter the perching behavior of their fly hosts.

Only invertebrates have been enslaved by parasites.

Which statement best summarizes Elton's views on succession? Communities are like an organism with various interacting parts; responses to the prevailing conditions by individual species matter little. Each community has its own predictable life history; left undisturbed, the community will ultimately reach a stable, predetermined endpoint. Organisms and the environment interact to shape the direction that succession will take. Plant communities are like "superorganisms"—that is, groups of species that work together in a mutual effort toward some deterministic end.

Organisms and the environment interact to shape the direction that succession will take.

In which biome would one most likely find the smallest percentage of NPP devoted to roots? Kansas grasslands Alaskan tundra Panamanian tropical forest Sahara desert

Panamanian tropical forest

Which statement about the snail-trematode system studied by Dybdahl and Lively is false? The type of parasite varied from year to year. Parasites infected snails from their home lake less effectively than those from other lakes. The most common genotype of snail often varied from year to year. The parasites can castrate male snails.

Parasites infected snails from their home lake less effectively than those from other lakes.

Which statement about parasitoids is false? Most parasitoids kill their hosts. Parasitoids lay eggs in or on another insect. Parasitoid larvae do not eat the host insect. Parasitoid larvae remain in the host insect.

Parasitoid larvae do not eat the host insect.

Which phenomenon is a major cause of the periodic glacial advances and retreats that have occurred over the last two million years? The Pacific Decadal Oscillation (PDO) Changes in the rate of continental drift El Niño Southern Oscillation (ENSO) Periodic changes of Earth's orbit from more circular to more elliptical

Periodic changes of Earth's orbit from more circular to more elliptical

Which of the following would most likely contribute to the long-term persistence of a fugitive species? Periodic disturbances Apparent competition Competitive exclusion Character displacement

Periodic disturbances

Which statement accurately describes a way plants allocate carbon that is not used in respiration? Plants allocate almost all carbon to increasing photosynthetic tissue. Plants growing in deserts allocate a lower proportion of NPP to roots relative to leaves and stems. Plants allocate carbon as a defense against herbivory. Plants growing in areas with high plant density allocate a higher proportion of NPP to roots relative to leaves and stems.

Plants allocate carbon as a defense against herbivory.

How do plants and animals differ in how they take in nutrients? Plants take in complex molecules; animals take up relatively simple chemicals and synthesize larger molecules. Plants need to take in nitrogen-containing molecules, but animals do not. Plants take in simple chemicals, which they synthesize into larger molecules; animals take up larger, more complex molecules. Plants must absorb all 20 amino acids, whereas animals are able to synthesize all amino acids.

Plants take in simple chemicals, which they synthesize into larger molecules; animals take up larger, more complex molecules.

The loss of mycorrhizae-plant associations, in both angiosperms and gymnosperms, would have which effect on the plants? Plants would be able to extract less water and fewer nutrients from the soil. Plants would be better protected from pathogens. Plants would be able to survive in a wider range of habitats. Plants would be able to extract more water and more nutrients from the soil.

Plants would be able to extract less water and fewer nutrients from the soil.

Place a species distribution in order from smallest to largest. Metapopulation < Population < Geographic range Geographic range < Metapopulation < Population Population < Metapopulation < Geographic range Geographic range < Population < Metapopulation

Population < Metapopulation < Geographic range

The figure is derived from studies of the populations and per-individual growth rates of three species of rodents in the U.S. desert southwest. According to the figure, which population(s) show(s) evidence of Allee effects? Populations A and B Population C only Population B only Population A only

Population A only

Which statement about population growth is true? Population growth can continue indefinitely. Population growth of field samples always has a λ of approximately 1. Population growth can be exponential for only as long as environmental conditions are favorable. Population growth models do not apply to humans.

Population growth can be exponential for only as long as environmental conditions are favorable.

Ecologists have been monitoring three metapopulations of sawflies. Population A has a patch colonization rate of 0.08 and a patch extinction rate of 0.11. Population B has a patch colonization rate of 0.05 and a patch extinction rate of 0.04. Population C has a patch colonization rate of 0.10 and a patch extinction rate of 0.08. According to Levins's metapopulation model, which of these populations would be expected to persist for a long time? Population A only Population B only Population C only Populations B and C

Populations B and C

Which statement about populations is false? Populations are all of the species in an area that are capable of interacting. The distribution of a species is the geographic area where the abundance of the species is greater than zero. Populations are dynamic entities that vary in size over time and space. A population is a group of individuals from the same species that interact with one another within a particular area.

Populations are all of the species in an area that are capable of interacting.

Where would a keystone species most likely be located in the figure? Position B Position A Position D Position E

Position A

Where would a foundation species most likely be located in the figure? Position C Position D Position A Position B

Position D

Which of the following would not be an example of density-dependent factors regulating population size? In conditions of overcrowding, some desert pupfish living in ponds will emigrate to other ponds if given the opportunity. In conditions of high density, mice are more susceptible to mortality from heat stress. The number of possible territories for robins is limited; thus when population sizes are high, a lower proportion of individuals can produce offspring. Predation on mosquitofish is high, regardless of population size.

Predation on mosquitofish is high, regardless of population size.

The figure shows the relationship between the relative proportion of prey type A that is available in an area and the proportion of prey type A in the total diet of three different predators. Which predator shows evidence that it prefers to eat the more common prey? Predator 1 only Predator 2 only Predator 3 only Both predator 1 and predator 2

Predator 2 only

Which scenario is a competitive network? Scenario I: Species 1 outcompetes species 2, which outcompetes species 3, which outcompetes species 1. Scenario II: Species 5 outcompetes species 6, which outcompetes species 7. Scenario III: Species 8 outcompetes species 9. Scenario III Scenario I None of them Scenario II

Scenario I

On Mount St. Helens, the intensity of disturbance ranged from extremely high (lava dome, pumice plain) to moderate (mudflow zone, blowdown zone), to low (scorch zone). In which area is the abiotic stress of low nitrogen availability most likely to control succession? Mudflow zone Pumice Plain Scorch zone Blowdown zone

Pumice plain

High productivity in the open ocean would most likely be found in upwelling zones. the South Pacific. the Labrador current. polar cells.

upwelling zones

King's Lomatia (Lomatia tasmanica) is a most unusual plant. In the wild, only a single genetic individual of this shrub is known to be alive, and this colony has existed for at least 40,000 years. When a branch of this shrub falls to the ground, it sometimes establishes roots, and thus can function as a physiologically independent plant that is genetically identical to all other plants in the colony. Which term refers to a clone that is a physiologically independent plant? Ramet Genet Biotic Gamete

Ramet

In some trees and shrubs, competition among seedlings causes individuals to be spaced relatively evenly throughout the habitat. These plants exhibit a _______ type of dispersion pattern. clumped regular ramet random

Regular

In some ecosystems, NPP actually decreases at very high levels of precipitation. Which of the following is not a likely reason for such declines in NPP? In areas where precipitation is extremely high, it is often cloudy, decreasing the amount of available sunlight. Respiration of heterotrophs increases at high precipitation levels. High precipitation levels can lead to low oxygen levels in the soil. High precipitation levels can lead to the leaching of nutrients from the soil.

Respiration of heterotrophs increases at high precipitation levels.

Assuming that the concept of a river continuum is correct, how would a second-, third-, and fourth-order river be ranked, in terms of the importance of terrestrial vegetation as a food source for the organisms within it? Fourth order > third order > second order Second order > third order > fourth order Second order > fourth order > third order Third order > second order > fourth order

Second order > third order > fourth order

Which factor most likely explains the synchrony of the hare population cycles in geographically distant areas? Isolation of the lynx Similarity of climate in these geographically distant areas Movement of hares Presence of competitive herbivores

Similarity of climate in these geographically distant areas

The map is of an imaginary planet that is roughly the same as Earth. Like Earth, it is tilted on its axis by about 23°, and it rotates around a sun-like star in approximately one year. At which site would a high-pressure system be most likely to develop during the winter? Site A Site C Site B Site D

Site D

Which observation led ecologists to conclude that resource limitation is not the only factor driving snowshoe hare cycles? Some declining hare populations do not lack food. Experimental addition of high quality food prevents hare populations from declining. Hare reproductive rates peak several years before densities reach a maximum. Hare population sizes rose and fell in synchrony across broad regions of the Canadian forest.

Some declining hare populations do not lack food.

Suppose you are studying succession patterns in two species, species A and species B, both small aquatic organisms that colonize bare surfaces underwater. You replicated Sutherland's experiments in this new system by placing bare tiles underwater in predator-protected areas and areas with predators. You collect data on the percent of cover for each species, as shown in the figure. Without predation, which species is a better competitor? Species A is a slightly better competitor than species B, but there is a lot of variability. Species B is a slightly better competitor than species A, but there is a lot of variability. Species A is a much better competitor than species B. Species B is a much better competitor than species A.

Species B is a slightly better competitor than species A, but there is a lot of variability.

One animal species (A) spends 10 minutes finding and obtaining one food item that contains 50 calories. The other animal species (B) spends 1 minute finding and obtaining one food item that contains 0.1 calories. Which statement best describes these animals? Species B is more likely to be a heterotroph than species A. Species B is more likely to be a detritivore than species A. Species B is more likely to be a predator than species A. Species A is more likely to be an autotroph than species B.

Species B is more likely to be a detritivore than species A.

Which statement about zero population growth isoclines of two competing species is true? Species coexistence requires that the two isoclines cross. The crossing of the two isoclines is a sufficient condition for species coexistence. If the species coexist, they will each do so at a higher density than either would if placed alone. Strongly competing species can only coexist if the two species have very different carrying capacities.

Species coexistence requires that the two isoclines cross.

Which statement about species geographic ranges is true? Geographic ranges only need to include one life stage. Endemic species are located throughout the world. Most species can be found throughout Earth. Species distribution models aid scientists and policymakers in making decisions about species protection plans.

Species distribution models aid scientists and policymakers in making decisions about species protection plans.

The Shannon index is a measure of species diversity. species richness alone. interaction strength. the extent of trophic facilitation.

Species diversity

Which statement about species richness and composition is true? Species richness is usually higher at low latitudes than at high latitudes. At a given latitude, species composition is almost always very similar across different continents. Species richness shows a generally consistent longitudinal gradient across Earth. If species composition changes substantially, then species richness must also change.

Species richness is usually higher at low latitudes than at high latitudes.

Based on the Lotka-Volterra equations, which statement about carrying capacity and species coexistence is most likely true? Species with similar resource use but very different carrying capacities are more likely to coexist than species with similar resource use and similar carrying capacities. Species with similar carrying capacities are more likely to coexist than species with different carrying capacities. Doubling the carrying capacities of two competing species should increase the likelihood that the species will coexist. Species with different carrying capacities are more likely to coexist than species with similar carrying capacities.

Species with similar carrying capacities are more likely to coexist than species with different carrying capacities.

If a biologist wanted to study a hot spring community and were to sample the bacterial species causing its various colors, this would be an example of what type of subset? None of the above taxonomic Functional Guild

Taxonomic

Deciduous trees would most likely be found in which of these forest types? Boreal forest Temperate evergreen forest Temperate shrubland and woodland Tropical rainforest

Temperate shrubland and woodland

Based on the figure, how does the climate change as one moves from the alpine to the subalpine to the montane zone of a mountain? Both temperature and precipitation decrease. Temperature decreases and precipitation increases. Temperature increases and precipitation decreases. Both temperature and precipitation increase.

Temperature increases and precipitation decreases.

The figure illustrates the Coriolis effect for Earth. Which of the following statements about the Coriolis effect is false? The Coriolis effect has a major impact on determining global patterns of ocean currents as well as winds. If the Earth was a cylinder (with its length oriented north-south and rotating around a north-south axis) rather than a sphere, no east-west deflection of a north-south trajectory would occur. If the Earth's direction of rotation was from east to west rather than west to east, the deflection would still occur, but its direction would be reversed. The Coriolis effect occurs because points on Earth close to the equator are rotating around Earth's axis more slowly than points farther from the equator.

The Coriolis effect occurs because points on Earth close to the equator are rotating around Earth's axis more slowly than points farther from the equator.

Which statement about CAM and C4 plants is true? They both open their stomata during the night. They both have differentiated mesophyll and bundle sheath tissue separated by a waxy layer. They both are typically found in wet climates. They both make use of the enzyme PEPcase.

They both make use of the enzyme PEPcase.

Which of the following hypotheses for the global latitudinal gradient in species is not supported by the figure? The tropics and temperate regions have had similar speciation rates, but extinction rates have been lower in the tropics. The tropics have had more time for diversification than temperate regions have. Temperate regions have experienced lower diversification rates than the tropics have. The tropics and temperate regions have had similar extinction rates, but speciation rates have been higher in the tropics.

The tropics have had more time for diversification than temperate regions have.

According only to the specifics of Levins's metapopulation model, which variable is important in determining whether a metapopulation can persist for a long time? The elevation of a patch The distance to new habitats The colonization and extinction rate of patches The spatial arrangement of patches

The colonization and extinction rate of patches

What characteristics are found in Pseudomyrmex ants that depend on acacias, compared to species of Pseudomyrmex that are not associated with acacias? They are more active and less aggressive. They are more active and more aggressive. They are more aggressive and less active. They are less active and less aggressive.

They are more active and more aggressive.

Which statement describes the most likely reason that a fish associated with a cleaner fish like Labroides dimidiatus does not eat the cleaner fish, even when the cleaner fish is in its mouth? The fish is being altruistic. The cleaner fish emits a chemical that makes the other fish more docile. They are more aggressive and less active. The benefit from parasite removal is greater than that from eating the cleaner fish.

The benefit from parasite removal is greater than that from eating the cleaner fish.

Which statement about predators and prey is true? Mimicry is found only in prey, not in predators. The body form of the cheetah enables it to have great bursts of speed, improving its likelihood of capturing gazelles and other prey. Prey capture is facilitated in snakes by the rigid connections among their skull bones. Only herbivores have anti-predator defenses.

The body form of the cheetah enables it to have great bursts of speed, improving its likelihood of capturing gazelles and other prey.

Which statement about logistic growth is false? The carrying capacity is the maximum population size that can be supported by the environment for one year. Logistic growth of a population can be represented by an S-shaped curve. At the carrying capacity, there is no population growth in the logistic model. At low densities, logistic growth is similar to exponential growth.

The carrying capacity is the maximum population size that can be supported by the environment for one year.

Benkman's experiment with five species of birds of the crossbill species complex showed that each species' bill morphology had a positive correlation with its preferred pine cone, which also provided the highest survival rate of each bird type. What major conclusion did Benkman make in response to this evidence? The crossbills are currently undergoing evolutionary divergence. The crossbills that prefer the most common type of cone will eventually outcompete the others. The crossbills' differences are due to past geographical isolation. The crossbills are very flexible in the type of cone they can eat, leading to their success as a spe

The crossbills are currently undergoing evolutionary divergence.

What is measured by the lapse rate? The decline in temperature as one moves up in altitude The decline in atmospheric pressure as one moves up in altitude The decline in temperature as one moves away from the equator The amount of water that air can hold as temperature changes

The decline in temperature as one moves up in altitude

Which criterion is most important in determining whether an ecological relationship is a symbiosis? Whether both parties benefit Whether the parties are from the same kingdom The degree of proximity between the two parties The number of parties in the interaction

The degree of proximity between the two parties

Which of the following is not an abiotic feature of the environment? The salt content of sea mist The amount of sunlight the soil receives The salinity of the soil The density of earthworms present in the soil

The density of earthworms present in the soil

Which statement about early primary succession is false? The first colonizers usually can modify the habitat to benefit their growth and reproduction. The process can be very slow. The first colonists typically face hostile conditions. The first colonists typically cannot withstand much physiological stress

The first colonists typically cannot withstand much physiological stress

Which statement best explains why tropical plants may lose function at temperatures as high as 10°C, while alpine plants can function at temperatures close to freezing? The enzymes of tropical plants become denatured at 10°C, whereas the enzymes of alpine plants do not. The alpine plants can function even when their membranes have solidified, whereas the tropical plants cannot. The metabolic coordination of alpine plants makes them able to withstand lower temperatures. The membranes of alpine plants have a higher proportion of unsaturated lipids, making them less sensitive to lower temperatures.

The membranes of alpine plants have a higher proportion of unsaturated lipids, making them less sensitive to lower temperatures.

Suppose that a species of moss cannot coexist with a superior competitor unless there is periodic disturbance. This species is also a frequent disperser. Which conclusion is most likely? The moss is engaged in character displacement. In a constant environment, the moss and its competitor have zero population growth isoclines that cross. The moss is a fugitive species. The moss demonstrates competitive reversal.

The moss is a fugitive species.

Which statement describes a finding of Wilson and Tilman's studies of the grass Schizachyrium scoparium? The plants compete only for aboveground resources. The plants compete only for belowground resources. The plants compete for both aboveground and belowground resources, and competition is most intense for whichever resources are scarcer. The plants compete for both aboveground and belowground resources, and competition is most intense for whichever resources are more abundant.

The plants compete for both aboveground and belowground resources, and competition is most intense for whichever resources are scarcer.

In the succession that followed the eruption of Mount St. Helens, which organism played an important role as an ecosystem engineer? The toad Bufo boreas The pocket gopher Thomomys talpoides The salamander Ambystoma gracile The frog Rana cascadae

The pocket gopher Thomomys talpoides

Which of the following is an example of something that could be predicted with information on a species' "climate envelope"? The range that the species could potentially inhabit The growth rate of the species The reproductive rate of that species The survival rate of the species

The range that the species could potentially inhabit

Use the figure to determine the point at which the population growth rate is maximized under the logistic model. The rate is maximized when N = K/2. The rate is maximized when K is reached. The rate is maximized when the population is extremely small. The rate is maximized when K is surpassed.

The rate is maximized when N = K/2.

Suppose that, instead of the results actually obtained in Brown and Davidson's experiments, the number of rodents in the ant-excluded treatment was roughly the same as the number of rodents in the control group, and the number of ants in the rodent-excluded treatment was roughly the same as the number of ants in the control group. Which of the following would you then conclude? Competition is asymmetrical, with rodents affecting ants more than ants affect rodents. The two species have reduced competition through resource partitioning. Competition is asymmetrical, with rodents affecting ants less than ants affect rodents. There has been a competitive reversal.

The two species have reduced competition through resource partitioning.

In his experiments with different competing pairs of Paramecium species, Gause found that sometimes both species persisted and sometimes only one species did. Which hypothesis did Gause propose in order to explain the cases in which both species persisted? One species was a much better competitor than the other. Periodic disturbance allowed for coexistence. The two species tended to use different resources. The two species exhibited only interference competition, not exploitative competition.

The two species tended to use different resources.

Acacia plants often have ants of the genus Pseudomymex associated with them. Removal of ant colonies from individuals of the bullhorn acacia species results in which change in the acacias? They form partnerships with other ant species. They grow considerably larger. Their survival rate increases. Their growth is considerably stunted.

Their growth is considerably stunted.

In a metapopulation, why does the colonization rate decrease as p becomes very large? Extinction rates are higher. There are few empty patches available for colonization. Patches are exactly the same. Patches are far away from each other.

There are few empty patches available for colonization.

Which statement about population growth is true? There are limits to the growth of populations. Exponential population growth is always faster than geometric population growth. We use the term "exponential growth" when the individuals in the population reproduce in synchrony at discrete intervals. A population that has a λ of 0.88 should grow in size.

There are limits to the growth of populations.

Which statement about allochthonous inputs is false? They are usually of higher quality than autochthonous inputs. They are energy inputs from autotrophs of a different ecosystem. They are generally more important in stream ecosystems than in marine ones. The fraction of allochthonous energy that is actually used is lower than the inputs indicate.

They are usually of higher quality than autochthonous inputs.

Which statement about the mammal fauna native to North and South America is true? There are some differences because the two continents were originally part of different "super continents." They show some similarities because the Americas, distinct from Europe, Asia, and Africa, were once part of the same "super continent." They show strong differences because the two continents were never connected. They show some similarities because the two continents split apart about 6 million years ago.

There are some differences because the two continents were originally part of different "super continents."

What is the advantage for a male cricket parasitized by hairworms to seek out water? By hydrating the cricket, the water decreases the negative effects of the parasite. There is no advantage for the cricket; the cricket's behavior is advantageous only to the parasite. Female crickets live near the water; by going to the water, the infected cricket can increase his chances of mating before the parasite kills him. There is no advantage for the infected cricket, but by going to the water and drowning, the cricket reduces the prevalence of parasitism in the species.

There is no advantage for the cricket; the cricket's behavior is advantageous only to the parasite.

Suppose corals had never evolved on Earth. What is one way in which Earth's oceans would likely be different today? There would be no ocean algae. There would be fewer islands. There would be more fish. Ocean ecosystems would be more diverse.

There would be fewer islands.

When wolves were returned to Yellowstone National Park in 1995, some of the effects noted were increasing levels of berries available to black bears, stabilization of stream banks, increased nesting habitat for birds, and increasing beaver numbers as a result of rejuvenating aspen trees. These were later determined to be the results of reduced numbers and altered feeding behavior of elk as they were preyed upon by the wolves. Given this information, which of the following best describes wolves in Yellowstone National Park? They are an ecosystem engineer. They are a foundation species. They are a primary consumer. They are a keystone species.

They are a keystone species.

Which statement about foundation species is true? They have low abundance but strong effects on the community. They are also keystone species. They cannot be ecosystem engineers. They have strong community effects due to their high abundance.

They have strong community effects due to their high abundance.

Which statement about Patterson's study of the distributions of Tamias chipmunks in the southwestern United States is false? They were manipulative experiments. They suggested that competition is limiting the ranges of the species. It found that in mountain ranges where only one species was present, that species was found over a broader distribution of habitats than would have been possible in the presence of a competitor. It found that in mountain ranges where two species were present, the overlap of their distributions was small.

They were manipulative experiments.

Two species of grasshoppers live in the same area. They both feed on plants, but the presence of one species does not affect the survival or the reproduction of the other. What type of competition is this? Interference Exploitative Allelopathy This is not an example of competition.

This is not an example of competition.

A bacterium provides essential amino acids to an aphid, which in turn provides sugars to the bacterium. Assuming that each partner is benefiting from the interaction, this would be an example of which type of mutualism? Service Metabolic Chemical Trophic

Trophic

What is the correct ranking in total global NPP of the following terrestrial biomes, from highest to lowest? Temperate forest > crops > tropical savanna Tropical savanna > temperate forest > crops Tropical savanna > crops > temperate forest Crops > tropical savanna > temperate forest

Tropical savanna > temperate forest > crops

In which biome would you most likely see the greatest percentage of NPP devoted to roots? Tropical forest in Panama Boreal forests in Russia Tundra in Alaska Pine savannas in Belize

Tundra in Alaska

Mountain gorillas put a lot of effort in raising their young, ensuring they are protected and well cared for. In a natural population in the absence of poaching, and a lack of habitat destruction and other manmade dangers, the mountain gorilla would represent which type of survivorship curve? Type III Type IV Type II Type I

Type I

Which type of survivorship curve is seen most frequently in the wild? Type I and Type II are about equally common. Type I (most individuals survive to old age) Type III (most individuals die young) Type II (constant rate of mortality throughout lifetime)

Type III (most individuals die young)

Which of the following examples emphasizes the importance of species composition? Determining that a particular forest is dominated by one or two species Knowing that there are seven tree species in a particular forest Measuring the total abundance of all tree species in a forest Understanding the influence of the loss of a species of trees on a particular forest

Understanding the influence of the loss of a species of trees on a particular forest

Why is upwelling important for the commercial fishery industry? -Upwelling equally distributes anoxic sediment throughout the water column. -Upwelling deposits detritus on surface waters. -Upwelling brings nutrient-rich waters to nutrient-poor surface waters. -Upwelling takes nutrient-rich water from the surface to the bottom of the ocean.

Upwelling brings nutrient-rich waters to nutrient-poor surface waters.

Which factor in the association between figs and fig wasps, if true, indicates that they have gone and/or are undergoing coevolution? Both species are tropical, indicating high rates of evolution. Wasp reproductive behavior is highly specialized to benefit figs. The association is facultative. The association is mutually beneficial.

Wasp reproductive behavior is highly specialized to benefit figs.

Most wasps are carnivores, but one group feeds on pollen and nectar and pollinates the flowers they visit. Wasps are less efficient than bees at pollination because their bodies are not covered with fuzzy hairs and therefore, pollen is less likely to stick to them. But masarine wasps specialize in pollinating certain species, including beardtongues (Penstemon sp.). Given this information, how will the costs and benefits of masarine wasp-plant mutualisms likely compare to those of bee-plant mutualisms? Costs and benefits will be about the same for both mutualisms. Wasp-plant mutualisms will have higher costs and higher benefits. Wasp-plant mutualisms will have higher costs and lower benefits. Wasp-plant mutualisms will have lower costs and lower benefits.

Wasp-plant mutualisms will have higher costs and lower benefits.

What takes place during the first step of photosynthesis, referred to as the "light-driven reactions"? CO2 is fixed, producing carbohydrates. Chlorophyll is oxidized by water. Water is split to provide electrons to synthesize ATP and NADPH. CO2 is oxidized by solar radiation.

Water is split to provide electrons to synthesize ATP and NADPH.

Which web(s) in the figure is(are) an interaction web? Web I Web II Web III Web II and Web III

Web II

In contrast to C3 plants, C4 plants have which structure that keeps the CO2 concentration high where the Calvin cycle operates? A waxy coating around the xylem Spongy mesophyll cells Well-differentiated mesophyll cells and bundle sheath tissue with a waxy coating Stomata in the lower and upper epidermis

Well-differentiated mesophyll cells and bundle sheath tissue with a waxy coating

Which statement about population fluctuations is false? All natural populations fluctuate in size. Population fluctuations can be caused by changes in density-independent factors. With abundant resources, a population can increase indefinitely. Population fluctuations can be caused by changes in density-dependent factors.

With abundant resources, a population can increase indefinitely.

Which observation would be the strongest evidence that character displacement is occurring? Competing species are more morphologically similar when apart than when they are together. The outcome of competition reverses after a period of time. Within species, individuals that resemble their competitors the most have a selective advantage. Within species, individuals that resemble their competitors the most have a selective disadvantage.

Within species, individuals that resemble their competitors the most have a selective disadvantage.

Which species has been documented as imposing penalties on individuals of its mutualistic partner that are engaged in overexploitation? Yucca plants of the yucca-yucca moth system Figs of the fig-fig wasp system Fig wasps of the fig-fig wasp system Yucca moths of the yucca-yucca moth system

Yucca plants of the yucca-yucca moth system

Two species of ground crickets compete in the eastern United States. In colder areas, Allonemobius fasciatus outcompetes Allonemobius socius, but in warm areas, A. socius outcompetes A. fasciatus. This is an example of a competitive reversal. allelopathy. a conspecific precedence. a character displacement.

a competitive reversal.

In the Lotka-Volterra predator-prey model, an increase in the capture efficiency (a) should lead to _______ in the long-term average number of predators and _______ in the long-term average number of prey. an increase; a decrease an increase; no change a decrease; a decrease no change; no change

a decrease; a decrease

Considering the food web, imagine a circumstance where a new, mutually beneficial relationship develops between H2 and H3, increasing both of their numbers. The effects of this on P2 and C2 are best described as an indirect positive effect on P2 and a direct negative effect on C2. a trophic facilitation effect on both C2 and P2. a direct negative effect on P2 and a trophic facilitation effect on C2. a direct negative effect on both C2 and P2.

a direct negative effect on P2 and a trophic facilitation effect on C2.

The coldest part of a large lake is usually in which zone? Benthic Photic Littoral Pelagic

benthic

On what time scale does the El Niño Southern Oscillation (ENSO) occur? Between 2 and 10 years Monthly Daily Seasonal

between 2 and 10 years

Suppose that a predatory fish eats only minnows and the predator-prey interaction follows Lotka-Volterra dynamics. The intrinsic growth rate of minnows in the absence of predators is 0.2 per month, and the mortality rate of the predatory fish in the absence of minnows is 0.1 per month. The capture efficiency rate is 0.004, and the efficiency at which minnow biomass is converted into predator biomass is 0.25. The predatory fish population will increase only if the number of minnows is above 50. above 100. below 50. below 100.

above 100.

A mouse exposed to reduced levels of oxygen initially cannot run as fast as usual, but after a week its performance improves. This is an example of _______ to _______. acclimatization; hypoxia adaptation; hypoxia adaptation; hypothermia acclimatization; hypothermia

acclimatization; hypoxia

A tourist travels to the Himalayas, the highest mountains in the world. At first, she has difficulty hiking due to shortness of breath, but after a week, her performance has improved. This is most likely an example of _______ to lower partial pressure of oxygen. The lower oxygen condition is also known as _______. adaptation; hyperoxia adaptation; hypothermia acclimatization; hypoxia acclimatization; hyperoxia

acclimatization; hypoxia

An individual zooplankton can change its solute concentrations in response to a change in water salinity. This response is an example of _______ in the form of a(n) _______ adjustment. acclimatization; osmotic adaptation; turgor adaptation; osmotic acclimatization; stomatic

acclimatization; osmotic

Which scientist conceptualized Earth as divided into six biogeographic regions and is considered the father of biogeography? Robert MacArthur Alfred Russel Wallace Charles Darwin Edward O. Wilson

alfred russel wallace

Which human activity can bring about shifts in communities to alternative stable states? All of the above Habitat destruction Introduction of invasive species Overexploitation of native species

all of the above

Which statement about ice is true? Ice formation at the surface of ponds prevents warming of the waters below. All of the above It is less dense than liquid water. It has a higher albedo than open water has.

all of the above

Black walnut trees release chemicals that can be toxic to other plants. This phenomenon may be an example of _______, although experimental confirmation is still needed. isoclines exploitative competition allelopathy character displacement

allelopathy

A leaf from a deciduous forest that falls into a large stream and is consumed by insects would be a source of _______ energy for the stream ecosystem. autochthonous assimilation allochthonous apichthonous

allochthonous

At low population densities, the flocking behavior of some species of birds is disrupted to the extent that the population growth rate is lower at very low densities than it is at somewhat higher densities. This is an example of environmental stochasticity. genetic drift. an Allee effect. dampened oscillations.

an allele effect

Due to their low density, females of a species of turtles have difficulty finding mates. As a result, the population's growth rate has been low, despite ample resources. This is an example of an Allee effect. genetic drift. environmental stochasticity. isolation by distance.

an allele effect

In wetland sediments, the physiological functioning of organisms is most likely to be negatively affected by _______ conditions. anoxic anadromous photic alkaline

anoxic

Many species of butterflies are noxious to predators. They also have bright red coloration that indicates to the potential predators that they are unpleasant or even harmful to eat. This is an example of _______ coloration. exploitative cryptic apomitic aposematic

aposematic

One characteristic of freshwater ecosystems, as compared with terrestrial ecosystems, is that freshwater ecosystems have been less affected by human impact. are defined by the animals they contain as well as the plants. show more variability in temperature. occupy more surface area.

are defined by the animals they contain as well as the plants.

A bacterium that obtains energy by converting inorganic compounds in its environment is a(n) autotroph because it carries out photosynthesis. heterotroph because it does not obtain energy from organic compounds. autotroph because it carries out chemosynthesis. heterotroph because it does not obtain energy from photosynthesis.

autotroph because it carries out chemosynthesis.

Which organisms would most likely be able to tolerate the 90°C environments that occur in hot springs? Mollusks Insects Bacteria Fish

bacteria

Which type of mammals would you most likely find on a small oceanic island that is 2,000 kilometers away from any other land mass and has not been colonized by humans? Bats Wild pigs Kangaroos Horses

bats

Suppose that a predatory fish eats only minnows and the predator-prey interaction follows Lotka-Volterra dynamics. The intrinsic growth rate of minnows in the absence of predators is 0.2 per month, and the mortality rate of the predatory fish in the absence of minnows is 0.1 per month. The capture efficiency rate is 0.004, and the efficiency at which minnow biomass is converted into predator biomass is 0.25. The minnow population size will increase only if the number of predatory fish is below 50. equal to 50. above 50 below 100.

below 50.

Bald eagles, which feed mainly on fish, tend to have much higher concentrations of toxins than the fish have. The same situation occurs for many top predators. This phenomenon is referred to as biomagnification. Carson's syndrome. bioaccumulation. bioremediation.

biomagnification.

The use of specialized bacteria to help break down a toxic organic pesticide spilled during an industrial accident is an example of the practical application of the CAM pathway. biological control. bioremediation. metabolomics.

bioremediation.

A hummingbird pollinating a plant in exchange for food is an example of both a service mutualism and a habitat mutualism. only a trophic mutualism. both a habitat mutualism and a trophic mutualism. both a service mutualism and a trophic mutualism.

both a service mutualism and a trophic mutualism.

Kangaroo rats adapted to the desert will produce water through their metabolizing of food. rely on behavioral strategies to minimize water loss. produce more sweat during the hottest part of the day to reduce their body temperature. Both b and c

both b and c

At the light intensity of 500 μmol/m2/s, the plants that are light-limited are those that are acclimatized to high-intensity light only. both medium-intensity and low-intensity light. both high-intensity and medium-intensity light. low-intensity light only.

both medium-intensity and low-intensity light.

In the figure, assume that the top line has a slope of 1 and the middle line a slope of 0.7. Which of the three relationships shown illustrates a scenario in which local processes most strongly limit species richness in a community? Bottom Top Impossible to say without knowing the beta and gamma diversity for each scenario Middle

bottom

The zone of turbulent air flow close to the surface of an object is referred to as a _______ layer. turbulence boundary protective resistance

boundary

Earthworms contribute to decomposition by breaking down matter into inorganic nutrients through mineralization. releasing enzymes that convert inorganic molecules into organic macromolecules. breaking up litter into smaller particles, thereby increasing the surface area and allowing for more efficient chemical breakdown. decreasing the amount of oxygen in the soil, thereby increasing mineralization.

breaking up litter into smaller particles, thereby increasing the surface area and allowing for more efficient chemical breakdown.

The equilibrium point for species diversity on a small island near the mainland would be represented by which letter? A D C B

c

In the Lotka-Volterra predator-prey model, the parameter a represents the birth rate of prey. population growth rate of prey in the absence of predators. efficiency with which prey biomass is converted into predator offspring. capture efficiency of prey by predators.

capture efficiency of prey by predators.

A predatory wasp that feeds exclusively on herbivorous ants would be an example of a(n) _______ that is part of the _______ trophic level. omnivore; third carnivore; third carnivore; second herbivore; second

carnivore; third

Consider a population of birds that land on an island. Their numbers rise exponentially until they reach a population of 1,000 birds, after which they crash to 700 due to resource limitations. Over time, the population rises and falls until it stabilizes around a population of 850. What does this population size likely represent in terms of population growth? Maximum population size Carrying capacity Outbreak Fluctuation

carrying capacity

Rubisco is important in photosynthesis because it slows down photosynthesis to allow the plant to store carbon. catalyzes the uptake of CO2 and the synthesis of PGA. catalyzes the uptake of H2O and the synthesis of PGA. slows down photorespiration to allow the plant to store carbon.

catalyzes the uptake of CO2 and the synthesis of PGA.

An autotrophic organism living in a hydrothermal vent on the bottom of the ocean would be expected to obtain its energy through chemosynthesis only. photosynthesis only. mostly chemosynthesis, with only small amounts of photosynthesis. equal amounts chemosynthesis and photosynthesis.

chemosynthesis only.

By means of a process called _______, some bacteria can use forms of _______ as electron donors to take up CO2 and convert it to carbohydrates. chemosynthesis; sulfur chemosynthesis; nitrogen bacteriosynthesis; potassium bacteriosynthesis; phosphate

chemosynthesis; sulfur

The availability of nutrient cations such as Ca2+, K+, and Mg2+ to plants may be insufficient in some soils that have low amounts of _______ particles. These particles have _______ that allow them to hold onto cations and exchange them with the soil solution. sand; semicrystalline structures clay; weak negative charges sand; strong positive charges clay; irregular structures

clay; weak negative charges

The final theoretical stage of succession is called the _______ stage. omega ultimate climax penultimate

climax

It is _______ in mountains and highlands when compared to lowlands because _______. colder; there are more air molecules to absorb the infrared energy from the sun. about the same temperature; Earth loses heat to the atmosphere equally across elevations. colder; there are fewer air molecules to absorb the infrared energy radiating from the Earth's surface. warmer; mountains are closer to the sun.

colder; there are fewer air molecules to absorb the infrared energy radiating from the Earth's surface.

A bird species nests in a specific kind of tree. The tree is not harmed by the bird building its nest in the tree's branches, but the bird benefits from the shelter provided by the tree and is better able to successfully raise young. This is an example of endosymbiosis. mutualism. symbiosis. commensalism.

commensalism.

A deer accidentally carries the seeds of a weedy plant in its fur. Transporting the seeds neither helps nor harms the deer, but is beneficial to the plant. This is an example of a(n) mutualism. amensalism. symbiosis. commensalism.

commensalism.

A group of interacting species that occur together at the same place and time is known as a species network. population. community. metapopulation.

community.

As light increases, photosynthetic rates increase. The point at which photosynthetic rates equal the respiration rate is called the _______ point. limitation compensation saturation response potential

compensation

Insects feeding on the leaves of a plant stimulate the plant to produce more leaves. This is an example of aposematism. compensation. competition. an induced defense.

compensation.

Which of the following is a biotic factor that can be an agent of change? A hurricane Drought A forest fire Correct! Competition

competition

Which of the following best explains why the mammal families in the Philippines are more similar to those in Africa than to those in New Guinea? Africa's closer proximity to the Philippines Continental drift High dispersal rates Biotic features of the environment

continental drift

The blue candle cactus, found in Mexico's Chihuahuan Desert, and Euphorbia polyacantha, found in the Eastern Hemisphere, both have succulent upright stems and protective spines. These similar characteristics result from high water availability. a close genetic relationship. convergence. desertification.

convergence

Some models of climate change suggest that the Gulf Stream may become weaker as global temperature increases. Such a weakening in the Gulf Stream would most likely result in warming in Seattle. cooling in Seattle. cooling in London. warming in London.

cooling in London.

On a warm day, a dog pants and some of the water on its tongue evaporates. This evaporation has a _______ effect that is caused by _______. warming; conduction cooling; conduction cooling; latent heat transfer warming; latent heat transfer

cooling; latent heat transfer

Moths resting on the trunks of trees often resemble the tree bark so that potential predators do not perceive them as prey. This is an example of crypsis. an induced defense. aposematic coloration. silencing.

crypsis

During a hurricane, a large segment of an insect population is carried to a distant island where there are abundant resources and minimal predators. What type of growth would you likely expect in the time immediately following this colonization event? Exponential Declining Logistic Linear

exponential

The rural community of Happyville has a population distribution made up of 112 individuals between the ages of 1-16, 222 individuals between 17-44, and 514 individuals over 45 years old. Based on this population distribution, without immigration or emigration, the population of Happyville would be expected to increase for 5 years then remain the same. stay the same for the next 50 years. increase over the next 50 years. decline over the next 50 years.

decline over the next 50 years.

The introduction of arctic foxes to some of the Aleutian Islands led to a drastic _______ in nitrogen-rich guano, and this change had the effect of transforming the islands from grassland to _______. increase; communities of small shrubs and forbs increase; tundra decrease; communities of small shrubs and forbs decrease; alpine forest

decrease; communities of small shrubs and forbs

As CO2 concentrations continue to increase in our atmosphere, photorespiration rates are likely to _______, a change that should _______ the advantage C4 plants have over C3 plants. decrease; decrease increase; decrease decrease; increase increase; increase

decrease; decrease

If the body size of an ectotherm with a semi-spherical body shape were to increase considerably, the surface area-to-volume ratio would _______, and the animal's ability to exchange heat with the environment would _______. decrease; increase increase; increase decrease; decrease increase; stay about the same

decrease; decrease

A population of wolves predates a population of moose on Isle Royale, Michigan, where there are fewer wolves than moose to start. The wolves prey on the moose and eat well, allowing them to have abundant offspring. However, as the wolf population rises, the moose population drops, and over time, the wolf population begins to drop also because of the reduced availability of resources. As the wolf population drops, moose are able to better survive and reproduce, causing the moose population to rise. With this abundance of moose, the wolf population is able to rebound until their population exceeds the moose population's ability to support the number of wolves. Which population dynamic does this series of oscillations represent? Carrying capacity Delayed density dependence Extinction vortex Delayed density independence

delayed density dependence

Suppose that only two females and a small number of males are left in a population of a highly endangered bird. Although all of these birds are healthy, by chance, both females fail to reproduce and the population goes extinct. This extinction is best described as a consequence of genetic drift. inbreeding. environmental stochasticity. demographic stochasticity.

demographic stochasticity

Which of the following would be least likely to cause the extinction of a population comprising 20 individuals within a single generation? A natural catastrophe Demographic stochasticity Allee effects Environmental stochasticity

demographic stochasticity

Population regulation occurs when? the population is close to zero. density-independent factors affect birth, death, and emigration rates. density-dependent factors affect birth, death, and emigration rates. the population has reached a stable age distribution.

density-dependent factors affect birth, death, and emigration rates.

Rivers and streams subjected to high amounts of nitrogen pollution export less nitrate than would be expected because moving stream water is affected by the processes of _______ and _______. mineralization; biological uptake denitrification; decomposition nitrification; decomposition denitrification; biological uptake

dentification; biological uptake

A beetle that feeds exclusively on dead wood is an example of a(n) _______ and is part of the _______ trophic level. herbivore; second detritivore; second herbivore; first omnivore; second

detritivore; second

If another predator were to begin competing with sea otters for the urchins, they would have a(n) _______ effect on otters and a(n) _______ effect on urchins. direct negative; direct negative direct negative; direct positive direct negative; indirect negative direct positive; direct negative

direct negative; direct negative

A species limited capacity to disperse, preventing it from reaching suitable habitat, is known as habitat dispersal. disturbance. dispersal limitation. migration.

dispersal limitation

A mudslide kills a large fraction of a population of a flower species. The reduction in this flower population allows for an increase in the population size of a fern that competes with the flower. This is an example of disturbance. stress. primary succession. facilitation.

disturbance

A powerful ice storm in 1998 felled a large proportion of trees across much of northern New England, New York State, and southeast Canada. Although the storm led to declines in abundance for many species of birds, it created opportunities for other bird species. With regard to its effects on the abundance of bird species, the 1998 storm would be considered a facilitator. biotic feature of the environment. dispersal event. disturbance event.

disturbance event

Decreases in _______ tend to increase the number of trophic levels in an ecosystem. disturbance frequency ecosystem area trophic efficiency NPP

disturbance frequency

The table shows the number of species of lizards present in the tropics, the subtropics, and the temperate zone over the last fifty million years. Of the three broad categories of hypotheses that have been proposed to explain latitudinal gradients (diversification rate, diversification time, and carrying capacity), these data best fit which hypothesis? Combination of diversification rate and diversification time Diversification time Diversification rate Carrying capacity

diversification rate

The total area of productive ecosystems required to support a particular individual or population is known as its carrying capacity. ecological footprint. logistic growth curve. survivorship curve.

ecological footprint

In a prairie ecosystem, mycorrhizal fungi form associations with the roots of prairie grasses, such as big bluestem. When the mycorrhizae are removed, the performance of big bluestem decreases, while the performance of other prairie grasses and wildflowers increases. This effect most clearly shows the influence of mutualisms on ecosystem structure. species distribution. species abundance. ecosystem diversity.

ecosystem structure.

A bacterium that causes rash on the skin of mammals upon infection would be classified as a(n) macroparasite. ectoparasite. endoparasite. parasitoid.

ectoparasite.

In the Lotka-Volterra predator-prey model, b represents the birth rate of prey. population growth rate of prey in the absence of predators. efficiency at which prey biomass is converted into predator offspring. capture efficiency of prey by predators.

efficiency at which prey biomass is converted into predator offspring.

The fly species Drosophila santomea is found only on a single small island. Thus, this fly is considered to be endemic. invasive. serendipitous. boreal.

endemic

In the years since Myxoma was introduced to Australia, the virus has _______ and rabbits have _______ resistance to the virus. evolved to become less lethal; evolved not changed in its lethality; evolved evolved to become more lethal; not changed in their level of evolved to become more lethal; evolved

evolved to become less lethal; evolved

For an ecological interaction to be a mutualism, the net benefits must be less than the net costs for both partners. be less than the net costs for one, but not necessarily the other, partner. exceed the net costs for one, but not necessarily the other, partner. exceed the net costs for both partners.

exceed the net costs for both partners.

A small population of 100 organisms is only able to contribute 25 offspring to the next generation, but during that time, 30 individuals in the population die. In the next iteration, the remaining 95 individuals generate only 20 offspring, but during that time, 30 individuals of the population die. The remaining 85 individuals generate only 15 offspring, but during that time, 30 individuals of the population die. Which of the following terms best describes what this population is experiencing? Carrying capacity Extinction vortex Ineffective population size Negative exponential growth

extinction vortex

In a metapopulation setting, habitat fragmentation generally causes the _______ rate to increase and _______ to decrease. colonization; the extinction rate colonization; environmental stochasticity extinction; the colonization rate extinction; genetic drift

extinction; the colonization rate

Climate's control of the geographic distribution of organisms is influenced by _______ more than _______. extreme conditions; average conditions weather; climate average conditions; extreme conditions fire; floods

extreme conditions; average conditions

Suppose that following a lava flow, pine grass (a hypothetical species) is the first species to colonize the area. Chemicals produced by pine grass change the soil chemistry in the environment, but these chemicals promote subsequent colonization by later species. Which model would best explain this scenario of succession? Facilitation Inhibition Tolerance Compensation

facilitation

Which process or event is most responsible for current species losses in the Amazon? Global climate change Invasive species Fragmentation Overexploitation

fragmentation

Which early ecologist maintained that plant communities are analogous to "superorganisms"? Henry Cowles F. Stuart Chapin Fredrick Clements Henry Gleason

frederick clements

Suppose that rabbits are the only prey and food supply of foxes, and that the predator-prey interaction follows Lotka-Volterra dynamics. The mortality rate of foxes in the absence of rabbits is 0.1 per week, and the intrinsic growth rate of rabbits in the absence of predation is 0.2 per week. The capture efficiency is 0.002, and the efficiency at which rabbit biomass is converted into fox biomass is 0.2. If there are initially 30 foxes and 400 rabbits, the net growth rate in the fox population will be a _______ of _______ per week. loss; 3 loss; 1.8 gain; 1.8 gain; 4.8

gain; 1.8

Suppose that rabbits are the only prey and food supply of foxes, and that the predator-prey interaction follows Lotka-Volterra dynamics. The mortality rate of foxes in the absence of rabbits is 0.1 per week, and the intrinsic growth rate of rabbits in the absence of predation is 0.2 per week. The capture efficiency is 0.002, and the efficiency at which rabbit biomass is converted into fox biomass is 0.2.If there are initially 30 foxes and 400 rabbits, the overall rate of change in the rabbit population will be a _______ of _______ per week. loss; 24 loss; 16 gain; 56 gain; 80

gain; 56

Regional species diversity is also referred to as _______ diversity. beta gamma delta alpha

gamma

Although there are approximately 10,000 cheetahs left in the wild, biologists think that their numbers were much lower at some time in the past because cheetah populations have very little genetic variation. What is the most likely reason for the lack of genetic variability in cheetahs? Genetic stochasticity Genetic drift Environmental stochasticity Demographic stochasticity

genetic drift

In the summer, leaves of E. farinosa show _______ pubescence than in the winter. The change in pubescence is an example of _______. less; acclimatization greater; transpiration greater; adaptation greater; acclimatization

greater; acclimatization

A biome extends across several continents. Parts of the biome on the different continents can be best identified by the growth forms of its plants. types of megafauna present. average temperatures. amount of disturbance.

growth forms of its plants.

During a dry period, a plant's rates of photosynthesis and transpiration both decrease. This suggests that the plant has its stomates closed. has its stomates open. is operating under light limitation. is operating under light saturation.

has its stomates closed.

Despite being photosynthetic, mistletoe receives some of its energy from its host plant. Mistletoe is thus an example of a heterotroph. holoparasite. hemiparasite. hyperparasite.

hemiparasite.

Within trophic levels, detritivores are grouped with _______ because _______. herbivores; detritus is part of the first trophic level primary carnivores; all "vores" consume animals autotrophs; detritus is part of the first trophic level autotrophs; detritus is waste made during energy production

herbivores; detritus is part of the first trophic level

Milkweed beetles are so named because they feed on the milkweed plant. They are _______ and are part of the _______ trophic level. detritivores; first herbivores; first =herbivores; second carnivores; first

herbivores; second

The first organisms on Earth were most likely autotrophs that obtained energy through the C4 photosynthetic pathway. heterotrophs that obtained energy from CO2 and high-energy nitrogen compounds. heterotrophs that obtained energy from amino acids and sugars forming spontaneously in the early atmosphere. autotrophs that obtained energy through the CAM photosynthetic pathway.

heterotrophs that obtained energy from amino acids and sugars forming spontaneously in the early atmosphere.

Across various sites within the rainforest of Panama, different species of trees are found with little overlap among sites. Based on this pattern of species turnover, Panama's rainforest is best described as having _______ diversity. low beta high beta low alpha high alpha

high beta

A factor that makes temperate grassland biomes particularly well suited for conversion into agricultural land is their generally low level of precipitation. inability to support forests. high level of soil organic matter. frequency of fires.

high level of soil organic matter.

Higher trophic levels often have _______ concentrations of toxins due to the process of _______. higher; bioremediation lower; bioaccumulation higher; biomagnification lower; biomagnifications

higher; biomagnification

Compared with large endotherms, small endotherms require _______ feeding rates, partly because they have a _______ surface area-to-volume ratio. higher; higher similar; similar lower; higher lower; lower

higher; higher

According to the studies by Dyer and Letourneau, high densities of Tarsobaenus beetles in a lowland wet tropical forest led to _______ herbivory and _______ production. higher; lower lower; lower higher; higher lower; higher

higher; lower

Orchid species that have lost their ability to photosynthesize, and instead parasitize fungi for all their energy needs, would best be classified as holoparasites. photosynthetic organisms. chemosynthetic organisms. hemiparasites.

holoparasites.

The salinity of salmon is about 0.9%. Salmon living in water with 0.2% salinity would be _______ to the environment, and would tend to _______ water and _______ salts. hypertensive; lose; gain hypoosmotic; gain; lose hyperosmotic; gain; lose hypoxic; gain; lose

hyperosmotic; gain; lose

The inability of a system to shift back to the original community state, even after the original conditions have been restored, is called the climax stage. hysteresis. the photic state. an ecological valley.

hysteresis

Which statement best describes the difference between the theoretical concept of a community and the ways in which communities are delineated in practice? in theory, communities can be defined by physical or biological characteristics, but in practice, these characteristics are difficult to measure and are not used. In theory, a community is defined only by abiotic factors of the area; in practice, communities are delineated by biological attributes as well. In theory, communities consist of all species present; in practice, biologists usually study only a subset of the species. there is no difference between the theoretical concept of a community and how it is defined in practice.

in theory, communities consist of all species present; in practice, biologists usually study only a subset of the species.

In Paine's studies of ecosystems in the rocky intertidal zone, removal of Pisaster sea stars led to a long-term increase in mussels of the genus Mytilus. increase in gooseneck barnacles. decrease in mussels of the genus Mytilus. increase in species diversity.

increase in mussels of the genus Mytilus.

Deforestation in the tropics should result in a(n) _______ in the land's ability to reflect solar energy and _______ latent heat transfer. increase; decreased decrease; more variable increase; increased decrease; increased

increase; decreased

The figure shows the interaction between predator abundance and prey abundance. Populations of lynx and hares are located at the star. Based on the Lotka-Volterra predator-prey model, we would expect the number of prey to _______ and the number of predators to _______. increase; increase increase; decrease decrease; increase decrease; stay the same

increase; increase

What was the ultimate cause of the increase in mouse density according to this figure? Decreased rainfall Increased plant growth Increased rainfall Decreased plant growth

increased rainfall

From 1950 to 2010, the average sea temperature has _______ approximately _______oC. decreased; 10 decreased; 1 increased; 10 increased; 1

increased; 1

In his studies of succession in Glacier Bay, Chapin found that as communities went from early to latter stages of succession, soil moisture _______ and nitrogen _______. increased; decreased stayed about the same; increased decreased; increased increased; increased

increased; increased

Cougars prey on both white-tailed deer and mule deer. Because of their shared predator, each deer's species abundance is affected by the presence of the other deer species. The white-tailed and mule deer are engaged in a(n) trophic facilitation. indirect interaction. predator-prey relationship. direct interaction.

indirect interaction.

The presence of a mutualist spider in a certain area improves the survival of an herbaceous shrub by reducing the impact of herbivorous insects. These spiders are preyed on by lizards, and lizards are eaten by birds. The removal of birds from the area would most likely have a(n) _______ effect on spiders and a(n) _______ effect on the plant. indirect positive; indirect positive indirect negative; indirect negative indirect negative; indirect positive direct negative; direct negative

indirect negative; indirect negative

The secondary compounds that are produced by oaks to reduce herbivory are an example of a(n) compensation. aposematism. induced defense mimicry.

induced defense

in a hypothetical example of succession, the early succession plants produce toxins that hinder both the subsequent colonization of other early succession species and colonization by later succession plants. This scenario fits the _______ model of succession. facilitation tolerance inhibition Both a and b

inhibition

A fundamental niche is always the same as a realized niche. can only be altered if excess food is available to an organism. is often not realized because no one species has exclusive access to all the resources within its fundamental niche. is unrestricted by species-species interactions.

is often not realized because no one species has exclusive access to all the resources within its fundamental niche.

According to the figure, which loggerhead sea turtle group, when 50% protected by management practices, was estimated to produce a positive increase in survival growth rate? Large juvenile Egg/hatchling Small juvenile Subadult

large juvenile

Herbivores most commonly eat the _______ of plants. leaves stems roots seeds

leaves

Boston, Massachusetts, and Albany, New York, are at about the same latitude, but Albany is farther inland. Based on this, you would expect Albany to have _______ humidity and _______ variation in temperature than Boston. less; about the same more; less more; more less; more

less; more

Menge and colleagues performed experiments in which they exposed some populations of mussels to sea stars and excluded sea stars from other mussel populations. Suppose two populations of mussels are the same size prior to treatment, and after treatment there are 600 mussels in the treatment without sea stars and 200 mussels in the treatment with sea stars. Suppose further that the sea star population consists of 10 individuals. What is the per capita interaction strength of sea stars on mussels? (ln 600)/(ln 200) ln (3/10) ln (0.33/10) ln (0.33/200)

ln (0.33/10)

Plant species from resource-poor communities often have low growth responses to fertilization because these plants typically have a low intrinsic growth rate. low tolerance for excess nutrients. high intrinsic growth rate. high tolerance for excess nutrients.

low intrinsic growth rate.

The temperate deciduous forest biome has been developed for agriculture for centuries. More recently, the tropical forest biome is undergoing the same transition to agriculture, but with less success. The most likely reason the tropical forest biome has adapted less well to agriculture is that this biome, compared to the deciduous forest biome, has lower soil fertility. less precipitation. more pronounced seasons. lower temperatures.

lower soil fertility.

Character displacement is likely to _______ the competition coefficients in two competing species and to _______ resource partitioning. increase; increase lower; increase lower; eliminate increase; lower

lower; increase

Compared to carnivores, herbivores tend to have _______ assimilation energies because _______. lower; they are larger in size higher; plants contain many substances, such as cellulose, that are not easily digested lower; plants contain many substances, such as cellulose, that are not easily digested higher; they are smaller in size

lower; plants contain many substances, such as cellulose, that are not easily digested

A nearshore marine environment is located in a tropical area, and is home to salt-tolerant evergreen trees and animals including manatees and crab-eating monkeys. This environment is most likely a(an) salt marsh. rocky intertidal zone. mangrove forest. estuary.

mangrove forest.

All of the following factors can prevent predators from driving prey to extinction except habitat complexity. limited predator dispersal. marine extension. spatial refuges.

marine extension.

According to the basic host-pathogen model, if the combined death and recovery rate from a disease doubles, and the effectiveness of the disease to spread from infected to uninfected individuals also doubles, the threshold density should decrease by a factor of four. decrease by half. double. stay the same.

stay the same.

All nutrients are ultimately derived from minerals in rocks and gases in the atmosphere. detritus. rivers and streams. microorganisms.

minerals in rocks and gases in the atmosphere

Earth's surface releases _______ it receives by solar radiation. Additional energy inputs to Earth's surface occur in part from back radiation due to _______. more energy than; evapotranspiration less energy than; greenhouse gases about the same energy as; evapotranspiration more energy than; greenhouse gases

more energy than; greenhouse gases

If photosynthesis had not developed on Earth, living organisms would have led a harsher existence because of an overabundance of oxygen in the atmosphere. an inability to obtain energy from inorganic compounds. a much hotter atmosphere. more intense UV radiation reaching Earth.

more intense UV radiation reaching Earth.

All other things being equal, herbivores generally must consume _______ food than carnivores in order to meet their nutritional needs. The reason is that plant material, per gram of carbon, contains _______ nitrogen than animal material does. less; more more; less more; more less; less

more; less

Cool air is _______ dense than warm air; as air cools, it _______. less; sinks less; rises more; rises more; sinks

more; sinks

At the end of the Permian period (about 250 mya), Earth's land masses resembled the continents we now have. mostly made up a single large continent. were split into two major continents. were split into four major continents.

mostly made up a single large continent.

Based on the figure, an acorn barnacle has _______ chance of surviving to age 5 when compared to a song thrush. a significantly higher an approximately equal much lower no

much lower

During cold periods, marmots enter a state of torpor in order to alter their lower critical body temperature. In comparison to the body temperature of a bear during its long winter sleep, the temperature of the marmot drops _______, and the duration of the torpor is _______ the bear's period of sleep. much more; much shorter than much more; about the same as much less; much shorter than to about the same extent; much shorter than

much more; much shorter than

El Niño events are associated with droughts in the southeastern United States. much reduced or absent upwelling in the eastern Pacific Ocean. flooding in Indonesia and parts of Australia. greatly increased upwelling in the eastern Pacific Ocean.

much reduced or absent upwelling in the eastern Pacific Ocean.

Algae called zooxanthellae live in the tissues of corals. Their photosynthesis provides organic compounds that the corals use as food and the corals provide the algae with a safe place to live and with nutrients to use in photosynthesis. This relationship is best described as commensal (+/0). mutualistic (+/+). symbiotic (+/0). parasitic (+/−).

mutualistic (+/+).

The tolerance and the inhibition models of primary succession hold different assumptions about the nature of the disturbances and the opportunities they provide. nature of the effects that the early colonizing species have on other early colonizing species. strength of the disturbances and the extent of their impact on the habitat. nature of the effects that the early colonizers have on late colonizing species.

nature of the effects that the early colonizers have on late colonizing species.

Which biogeographical region is represented by X? Nearctic Temperate Palearctic Caribbean

nearctic

Suppose that a late succession plant that is surrounded by early succession plants grows at a rate of 0.5 cm per day. If the early succession plants are removed experimentally, the late succession plants are observed to grow at a rate of 0.9 cm per day. This experiment shows that the early succession plants have a _______ effect on the late succession plants, and this observation is most consistent with the _______ model of succession. negative; facilitation negative; inhibition positive; facilitation positive; inhibition

negative; inhibition

Not all consumed matter is incorporated into the biomass of a heterotroph. A heterotroph's growth is determined by its _______ secondary production, which equals ingestion minus _______. net; egestion and perspiration net; egestion and respiration net; chemosynthesis and perspiration gross; egestion and respiration

net; egestion and respiration

By a process known as _______, certain chemoautotrophic bacteria transform ammonia and ammonium into _______, which tends to be more available to plants than other forms of nitrogen. nitrogen fixation; N2 denitrification; N2 nitrification; nitrate nitrogen fixation; nitrate

nitrification; nitrate

The mixing that occurs at fall and spring turnover replenishes _______ in the epilimnion and increases the level of _______ in the hypolimnion. oxygen; biological activity oxygen; nutrients nutrients; sediments nutrients; oxygen

nutrients; oxygen

A nutrient-poor lake with low primary productivity is referred to as mesotrophic. oligotrophic. hypotrophic. eutrophic.

oligotrophic

Lake Condor is at 3,000 meters of elevation. The area around it has a short growing season and the lake is rather deep. Based on this information, we would expect the lake to be mesotrophic. benthic. eutrophic. oligotrophic.

oligotrophic

An earthworm eats primarily detritus. A robin that then eats the earthworm is operating on a trophic level _______ that of a rabbit that eats grass. one level above one level below two levels above that is the same as

one level above

When a plant is using transpiration to cool off during the day, its stomates are _______ and its water potential is _______ negative than that of the soil. At night, the plant's water potential will be _______ that of the soil (assuming that the soil is receiving sufficient moisture). open; more; roughly the same as closed; less; more positive than open; more; more positive than open; less; roughly the same as

open; more; roughly the same as

According to the work of Estes and others, an increase in _______ would lead to an increase in the abundance of urchins. orcas otters glades Opuntia stricta

orcas

The energy associated with dissolved solutes is called matric potential. kinetic osmosis. osmotic potential. pressure potential.

osmotic pressure

Which of the following best describes an explosion of the number of individuals in a population? Carrying capacity Population fluctuation Logistic growth Outbreak

outbreak

Thomas Park's studies of flour beetles and their protozoan parasite best exemplified the principle that selection can favor a diversity of host and parasite genotypes. parasites can alter the outcomes of competitive interactions between species. there are costs to both host defenses and parasite counterdefenses. parasites can drive host populations to extinction.

parasites can alter the outcomes of competitive interactions between species.

The studies by Dybdahl and Lively on snails and their parasites demonstrated that snails and parasites evolved at the same rate. snails cannot evolve in response to parasites. parasites infect common genotypes of snails more easily than they infect rare genotypes. snails evolve more quickly in response to parasites than parasites do to snails.

parasites infect common genotypes of snails more easily than they infect rare genotypes.

Nasonia vitripennis is a wasp roughly the size of a Drosophila fly. Adult females drill holes and lay eggs in the pupae of blowflies and related species. These eggs then hatch into larvae, which then eat the pupae. Thus, Nasonia vitripennis is a ectoparasite microparasite. hemiparasite. parasitoid.

parasitoid.

In equatorial regions, the sun's rays strike Earth's surface at a more _______ angle than they do toward the poles. This means that the same amount of energy is spread over a(n) _______ area in equatorial regions than in polar regions. acute (less than 90° angle); larger perpendicular; smaller perpendicular; larger acute (less than 90° angle); smaller

perpendicular; smaller

Which of the following is a plausible consequence of delayed density dependence in a population that would otherwise have logistic growth? Exponential growth Population cycles Increased environmental stochasticity Heightened oscillations

population cycles

Which of the following is an extreme case of population fluctuations? Logistic growth Demographic stochasticity Delayed density dependence Population outbreaks

population outbreaks

In Huffaker's studies of an herbivorous mite and its mite predator, when predator and prey were in a heterogeneous environment, prey and predator populations both increased for a while, but soon crashed and went extinct. predators soon went extinct, but prey persisted. predators and prey persisted, and maintained relatively stable population sizes. predators and prey persisted and exhibited population cycles.

predators and prey persisted and exhibited population cycles.

Different species of marine snails that are preyed on by a shore crab differ in terms of how easily the crab can crush their shells. Studies of these snails have provided evidence for the value of "gene silencing" in ecological studies. principle of compensation. presence of trade-offs between different antipredator adaptations. influence of exploitation in the distribution and abundance of food organisms.

presence of trade-offs between different antipredator adaptations.

In Huffaker's studies of an herbivorous mite and its mite predator, when predator and prey were in a simple environment, prey and predator populations both increased for a while, but soon crashed and went extinct. prey soon went extinct, but predators persisted. predators soon went extinct, but prey persisted. predators and prey persisted and exhibited population cycles.

prey and predator populations both increased for a while, but soon crashed and went extinct.

Suppose that the relative proportion of susceptible and infected individuals in a population remains the same, but the density of the overall population doubles. According to the βSI model, disease transmission should double. increase by the square root of two. remain the same. quadruple.

quadruple.

A fictional animal, the tribble, reproduces in synchrony at regular intervals. When the logarithm of a particular tribble population was plotted against time, the result was a straight and increasing line. Which statement about the tribble population is false? If the actual population size were plotted against time, the result would be an increasing J-shaped curve. The tribble population is increasing in size geometrically. The λ of the tribble population is constant and greater than 1. r = 0.

r = 0

A population of prickly pear cacti has 1,500 individuals with an intrinsic rate of increase (r) of 0.3. As the population gets close to its carrying capacity of 2,000 individuals, how will r change? r will be near 0. r will be slightly less than 0.3. r will be slightly more than 0.3. r will be less than zero.

r will be near 0

Suppose populations of a beetle species follow the logistic equation for growth. If a population is at 3/4 of its carrying capacity and its (per capita) growth rate in the absence of density-dependent regulation is r, what is its growth rate now? r/4 0 3r/4 r/2

r/4

Chemical weathering of minerals in rocks is an important source of nutrients because it recycles nutrients into the atmosphere. converts inorganic molecules to organic molecules. releases soluble forms of nutrients. changes the size and surface area of rocks through freezing and thawing.

releases soluble forms of nutrients.

Suppose that two species of Darwin's finches live on the same island and eat seeds, but one species tends to eat larger seeds than the other one does. Based on this observation, we can conclude that these species are engaged in competitive exclusion. allelopathy. interference competition. resource partitioning.

resource partitioning.

A researcher finds that the physical environment at a certain location alternates between marine and terrestrial with the rise and fall of the tides. A stable substratum provides an anchor against the pounding tides for a diverse array of organisms. Organisms that live there, especially those that are sessile, usually have high tolerance for changes in salinity, temperature, and desiccation. This area is most likely a(n) sandy shore. estuary. pelagic zone. rocky intertidal zone.

rocky intertidal zone.

A biome contains sagebrush and many types of cacti, as well as rattlesnakes and jackrabbits. It has a hot, dry climate, and many microbes, including bacteria and archaea, that are adapted to live in extreme conditions. Which of these factors would be used to classify this biome? Hot, dry climate Rattlesnakes and jackrabbits Sagebrush and cacti Microbes adapted to extreme environments

sagebrush and cacti

Which group shows greater species richness in the temperate regions than in the tropics? Amphibians Mammals Seed plants Seabirds

seabirds

Which of the following groups exhibits an atypical latitudinal species gradient? Terrestrial plants Landbirds Seabirds Mammals

seabirds

Because leaf-cutter ants and fungi help each other overcome plant defenses, the leaf-cutter ant-fungus mutualism can be described as which type of mutualism? Chemical Service Trophic Habitat

service

Consider both the particle size on the stream bottom and the number of rooted and floating macrophytes in a higher-order stream, such as the Mississippi River, compared to a small first-order source stream of the Mississippi. The river would have smaller particle size and more macrophytes. larger particle size and fewer macrophytes. smaller particle size and fewer macrophytes. larger particle size and more macrophytes.

smaller particle size and more macrophytes.

In van Helmont's experiment measuring a growing tree, which possible energy source for the tree's growth was he able to rule out? Oxygen soil Water Carbon dioxide

soil

By pitting two species of worms against each other at varying densities, researchers have determined that the zero growth isocline of species A is always above that of species B. This means that species A will always exclude species B. species B will always exclude species A. one species will exclude the other, depending on the initial conditions. both species will coexist at a lower density than either would alone.

species A will always exclude species B.

Consider two tropical forests, each of which has 2,700 species. Both forests possess 2,500 of the same species, but 200 of the species are present in either one or the other tropical forest, but not both. This consideration is a measure of species diversity. species composition. species richness. species evenness.

species composition.

Mosquitoes infected with Plasmodium carry cells of the _______ stage of the parasite. When an infected mosquito bites a human, these cells enter the _______, where they divide into _______ that then infect red blood cells. merozoite; liver; sporozoites sporozoite; liver; merozoites merozoite; spleen; sporozoites sporozoite; spleen; merozoites

sporozoite; liver; merozoites

If climate change causes a boreal forest to be a little warmer and a little wetter, it will most likely become temperate deciduous forest. tundra. savanna. temperate evergreen forest.

temperate deciduous forest.

An insect removes nectar from a flower without pollinating it. This is an example of the plant extracting a penalty from the insect. a typical mutualistic interaction between insect and plant. the insect acting as a cheater. the insect extracting a penalty from the plant.

the insect acting as a cheater.

Yucca plants retain 62% of the flowers that contain up to six moth eggs, but only 11% of the flowers containing nine or more eggs. The yucca aborts these flowers before the moth eggs hatch. This process is only effective for reducing exploitation by moths if the moth larvae in an aborted flower move to another yucca. moths that appear later are unable to lay eggs in the yucca flowers. the moth larvae in an aborted flower all die. moths are able to lay more eggs in the unaborted flowers.

the moth larvae in an aborted flower all die.

In the equilibrium model of island biogeography, once an "island" has reached equilibrium, the suite of species present on the island is stable. extinction rates drop to around zero. migration to the island ceases. the species richness on the island is stable.

the species richness on the island is stable.

What is the meaning of the statement: "The tropics are a museum of species diversity"? The tropics have low carrying capacities. The tropics have high diversification rates. The tropics have low extinction rates. The tropics have high extinction rate

the tropics have low extinction rates

What links animals together in the context of ecological function is their size. their roles in moving energy through the ecosystem. their evolutionary relationships. morphology.

their roles in moving energy through the ecosystem.

The primary difference between tundra and boreal forest is that trees are the dominant vegetation in boreal forests but not in tundra. nearly all tundra areas are very dry, whereas boreal forests are wet. the tundra generally lacks permafrost. herds of caribou and musk oxen live in boreal forests but not in tundra.

trees are the dominant vegetation in boreal forests but not in tundra.

Which climatic zone has the greatest land area? Temperate Tropical Boreal Subtropical

tropical

Which biome contains only 11% of Earth's terrestrial vegetation cover, but is home to about half of Earth's species? Temperate grassland Tropical seasonal forest Tropical rainforest Temperate deciduous forest

tropical rainforest

The climate of a certain region is warm to hot, with little seasonal variation in temperature, but with a pronounced dry season. The vegetation is mostly grasses, but there are some shrubs and trees. This region is most likely a desert. tropical savanna. temperate grassland. tropical dry forest.

tropical savanna

Which areas of Earth receive the most precipitation on average? Tropics Polar zones Temperate zones Regions near 30°N and S latitudes

tropics

Part B on the map shows the alteration of terrestrial biomes by human activities (i.e., the "human footprint"), with green representing the least human impact and purple-red representing the most. According to the map, which biome is overall least altered by human activity world-wide? Tropical rainforests Tundra Tropical seasonal forest Deserts

tundra

Loss of _______ pressure results in wilting of nonwoody plants due to dehydration. osmotic xyleic matric turgor

turgor

Suppose that a new river cuts through a land mass, separating populations of mice on either side. These mice then evolve into new species on the two sides of the land mass. This is an example of evolution by vicariance. subduction. species turnover. continental drift.

vicariance

Compared with land at the same latitude, ocean waters tend to be _______ in the winter and _______ in the summer because water has a _______ heat capacity than land has. warmer; warmer; higher colder; warmer; lower warmer; colder; higher colder; colder; lower

warmer; colder; higher

Alternative stable states most often arise in intertidal zones. under the tolerance model of succession. in terrestrial ecosystems. when there are strong interactions among species.

when there are strong interactions among species.

Plant ecophysiologists often measure the water potential of a plant at midnight to understand plant-soil-water relationships. If an investigator found that Ψstem was -2.0 MPa as shown in the figure, which statement would also be true? Ψair must be = -2.0. Ψleaf must be > -2.0. Ψsoil must be > -2.0. Ψsoil must be = -2.0.

Ψsoil must be = -2.0.

In the simple host-pathogen model, which term describes the rate at which a disease is transmitted? βdI βSI S SI

βSI