In July 2008, the United States had a population of approximately 302,000,000 people. How many Americans were there in July 2009, if the estimated 2008 growth rate was 0.88%?

In July 2008, the United States had a population of approximately 302,000,000 people. How many Americans were there in July 2009, if the estimated 2008 growth rate was 0.88%? 

A) 2,700,000
B) 5,500,000
C) 303,000,000
D) 304,000,000
E) 2,710,800,000





Answer: D

Which of the following is the equation for zero population growth (ZPG)?

Which of the following is the equation for zero population growth (ZPG)? 

A) R = b - m
B) dN/dt = rN
C) dN/dt =rmax N (K -N)/K
D) dN/dt =rmax N
E) dN/dt = 1.0N







Answer: A

Starting from a single individual, what is the size of a population of bacteria that reproduce by binary fission every 20 minutes at the end of a 2-hour time period? (Assume unlimited resources and no mortality.)

Starting from a single individual, what is the size of a population of bacteria that reproduce by binary fission every 20 minutes at the end of a 2-hour time period? (Assume unlimited resources and no mortality.) 

A) 6
B) 18
C) 128
D) 512
E) 1,024





Answer: D

A population of ground squirrels has an annual per capita birth rate of 0.06 and an annual per capita death rate of 0.02. Calculate an estimate of the number of individuals added to (or lost from) a population of 1,000 individuals in one year.

A population of ground squirrels has an annual per capita birth rate of 0.06 and an annual per capita death rate of 0.02. Calculate an estimate of the number of individuals added to (or lost from) a population of 1,000 individuals in one year. 

A) 120 individuals added
B) 40 individuals added
C) 20 individuals added
D) 400 individuals added
E) 20 individuals lost





Answer: B

Which of the following is the most important assumption for the capture-recapture method to estimate the size of wildlife populations?

Which of the following is the most important assumption for the capture-recapture method to estimate the size of wildlife populations? 

A) All females in the population have the same litter size.
B) More individuals emigrate from, as opposed to immigrate into, a population.
C) Over 50% of the marked individuals need to be trapped during the recapture phase.
D) There is a 50:50 ratio of males to females in the population before and after trapping and recapture.
E) Marked individuals have the same probability of being recaptured as unmarked individuals during the recapture phase.




Answer: E

Why do some invertebrates, such as lobsters, show a "stair-step" survivorship curve?

Why do some invertebrates, such as lobsters, show a "stair-step" survivorship curve? 

A) Many invertebrates mate and produce offspring on multiyear cycles.
B) Within a species of invertebrates, younger individuals have a higher survivorship than older individuals.
C) Many invertebrates molt in order to grow, and they are vulnerable to predation during their "soft shell" stage.
D) Many invertebrate species have population cycles that go up and down according to the frequency of sunspots.
E) The number of fertilized eggs that mature to become females in many species of invertebrates is based on ambient temperature.




Answer: C

Which of the following best defines a cohort?

Which of the following best defines a cohort? 

A) a group of individuals that inhabits a small isolated region within the range for the species
B) all of the individuals that are annually added to a population by birth and immigration
C) the reproductive males and females within the population
D) a group of the individuals from the same age group, from birth until they are all dead
E) the number of individuals that annually die or emigrate out of a population





Answer: D

Which of the following choices would most likely promote random distribution?

Which of the following choices would most likely promote random distribution? 

A) territorial species
B) species that secrete chemicals to attract or inhibit other individuals
C) flocking and schooling behaviors
D) spacing during the breeding season
E) homogeneous chemical and physical factors in the environment





Answer: E

Which of the following is the best example of uniform distribution?

Which of the following is the best example of uniform distribution? 

A) bees collecting pollen in a wildflower meadow
B) snails in an intertidal zone at low tide
C) territorial songbirds in a mature forest during mating season
D) mushrooms growing on the floor of an old growth forest
E) a cultivated cornfield in the Midwest





Answer: C

Which of the following scenarios would provide the most legitimate data on population density?

Which of the following scenarios would provide the most legitimate data on population density? 

A) Count the number of nests of a particular species of songbird and multiply this by a factor that extrapolates these data to actual animals.
B) Count the number of pine trees in several randomly selected 10 m x 10 m plots and extrapolate this number to the fraction of the study area these plots represent.
C) Use the mark-and-recapture method to estimate the size of the population.
D) Calculate the difference between all of the immigrants and emigrants to see if the population is growing or shrinking.
E) Add the number of births and subtract the individuals that die to see if the population's density is increasing or decreasing.





Answer: B

Which of the following sets of measurements is the most useful when studying populations?

Which of the following sets of measurements is the most useful when studying populations?

A) density, dispersion, and demographics of a population
B) gene frequency over time and the ratio of reproductive to nonreproductive individuals
C) annual precipitation averages and mean annual temperatures
D) minimum and maximum amounts of precipitation and annual temperature extremes
E) ratio of predators and the number of immigrants and emigrants







Answer: A

Long-term studies of Belding's ground squirrels show that immigrants move nearly 2 km from where they are born and become 1%-8% of the males and 0.7%-6% of the females in other populations. On an evolutionary scale, why is this significant?

Long-term studies of Belding's ground squirrels show that immigrants move nearly 2 km from where they are born and become 1%-8% of the males and 0.7%-6% of the females in other populations. On an evolutionary scale, why is this significant? 

A) These immigrants make up for the deaths of individuals, keeping the other populations' size stable.
B) Young reproductive males tend to stay in their home population and are not driven out by other territorial males.
C) These immigrants provide a source of genetic diversity for the other populations.
D) Those individuals that emigrate to these new populations are looking for less crowded conditions with more resources.
E) Gradually, the populations of ground squirrels will move from a clumped to a uniform population pattern of dispersion.







Answer: C

Which of the following assumptions have to be made regarding the capture-recapture estimate of population size? I. Marked and unmarked individuals have the same probability of being trapped. II. The marked individuals have thoroughly mixed with the population after being marked. III. No individuals have entered or left the population by immigration or emigration, and no individuals have been added by birth or eliminated by death during the course of the estimate.

Which of the following assumptions have to be made regarding the capture-recapture estimate of population size?
I. Marked and unmarked individuals have the same probability of being trapped.
II. The marked individuals have thoroughly mixed with the population after being marked.
III. No individuals have entered or left the population by immigration or emigration, and no individuals have been added by birth or eliminated by death during the course of the estimate. 

A) I only
B) II only
C) I and II only
D) II and III only
E) I, II, and III






Answer: E

Which of the following examples would most accurately measure the density of the population being studied?

Which of the following examples would most accurately measure the density of the population being studied? 

A) counting the number of prairie dog burrows per hectare
B) counting the number of times a 1 kilometer transect is intersected by tracks of red squirrels after a snowfall
C) counting the number of coyote droppings per hectare
D) multiplying the number of moss plants counted in 10 quadrats of 1m² each by 100 to determine the density per kilometer².
E) counting the number of zebras from airplane census observations.






Answer: E

To construct a reproductive table for a sexual species, one needs to

To construct a reproductive table for a sexual species, one needs to 

A) assess sperm viability for the males in the population.
B) keep track of all of the offspring of a cohort.
C) keep track of the females in a cohort.
D) keep track of all of the offspring of the females in a cohort.
E) analyze the ratio of deaths to births in a cohort.





Answer: C

Which of the following groups would be most likely to exhibit uniform dispersion?

Which of the following groups would be most likely to exhibit uniform dispersion? 

A) red squirrels, who actively defend territories
B) cattails, which grow primarily at edges of lakes and streams
C) dwarf mistletoes, which parasitize particular species of forest tree
D) moths, in a city at night
E) lake trout, which seek out cold, deep water high in dissolved oxygen





Answer: A

Uniform spacing patterns in plants such as the creosote bush are most often associated with

Uniform spacing patterns in plants such as the creosote bush are most often associated with 

A) chance.
B) patterns of high humidity.
C) the random distribution of seeds.
D) competitive interaction between individuals of the same population.
E) the concentration of nutrients within the population's range.







Answer: D

During the spring, you are studying the mice that live in a field near your home. The population density is high, but you realize that you rarely observe any reproductive female mice. This most likely indicates

During the spring, you are studying the mice that live in a field near your home. The population density is high, but you realize that you rarely observe any reproductive female mice. This most likely indicates 

A) that there is selective predation on female mice.
B) that female mice die before reproducing.
C) that this habitat is a good place for mice to reproduce.
D) that you are observing immigrant mice.
E) that the breeding season is over.





Answer: D

An ecologist recorded 12 white-tailed deer, Odocoileus virginianus, per square mile in one woodlot and 20 per square mile in another woodlot. What was the ecologist comparing?

An ecologist recorded 12 white-tailed deer, Odocoileus virginianus, per square mile in one woodlot and 20 per square mile in another woodlot. What was the ecologist comparing? 

A) density
B) dispersion
C) carrying capacity
D) cohorts
E) range







Answer: A

A population is correctly defined as having which of the following characteristics? I. inhabiting the same general area II. belonging to the same species III. possessing a constant and uniform density and dispersion

A population is correctly defined as having which of the following characteristics?
I. inhabiting the same general area
II. belonging to the same species
III. possessing a constant and uniform density and dispersion 

A) I only
B) III only
C) I and II only
D) II and III only
E) I, II, and III





Answer: C

Population ecologists are primarily interested in

Population ecologists are primarily interested in 

A) studying interactions among populations of organisms that inhabit the same area.
B) understanding how biotic and abiotic factors influence the density, distribution, size, and age structure of populations.
C) how humans affect the size of wild populations of organisms.
D) how populations evolve as natural selection acts on heritable variations among individuals and changes in gene frequency.
E) the overall vitality of a population of organisms.






Answer: B

If the direction of Earth's rotation reversed, the most predictable effect would be

If the direction of Earth's rotation reversed, the most predictable effect would be 

A) no more night and day.
B) a big change in the length of the year.
C) winds blowing from west to east along the equator.
D) a loss of seasonal variation at high latitudes.
E) the elimination of ocean currents.





Answer: C

Suppose that the number of bird species is determined mainly by the number of vertical strata found in the environment. If so, in which of the following biomes would you find the greatest number of bird species?

Suppose that the number of bird species is determined mainly by the number of vertical strata found in the environment. If so, in which of the following biomes would you find the greatest number of bird species? 

A) tropical rain forest
B) savanna
C) desert
D) temperate broadleaf forest
E) temperate grassland






Answer: A

When climbing a mountain, we can observe transitions in biological communities that are analogous to the changes

When climbing a mountain, we can observe transitions in biological communities that are analogous to the changes 

A) in biomes at different latitudes.
B) at different depths in the ocean.
C) in a community through different seasons.
D) in an ecosystem as it evolves over time.
E) across the United States from east to west.






Answer: A

Which statement about dispersal is false?

Which statement about dispersal is false? 

A) Dispersal is a common component of the life cycles of plants and animals.
B) Colonization of devastated areas after floods or volcanic eruptions depends on dispersal.
C) Dispersal occurs only on an evolutionary time scale.
D) Seeds are important dispersal stages in the life cycles of most flowering plants.
E) The ability to disperse can expand the geographic distribution of a species.






Answer: C

The oceans affect the biosphere in all of the following ways except

The oceans affect the biosphere in all of the following ways except 

A) producing a substantial amount of the biosphere's oxygen.
B) removing carbon dioxide from the atmosphere.
C) moderating the climate of terrestrial biomes.
D) regulating the pH of freshwater biomes and terrestrial groundwater.
E) being the source of most of Earth's rainfall.






Answer: D

Which of the following is characteristic of most terrestrial biomes?

Which of the following is characteristic of most terrestrial biomes? 

A) annual average rainfall in excess of 250 cm
B) a distribution predicted almost entirely by rock and soil patterns
C) clear boundaries between adjacent biomes
D) vegetation demonstrating vertical layering
E) cold winter months







Answer: D

Which of the following biomes is correctly paired with the description of its climate?

Which of the following biomes is correctly paired with the description of its climate? 

A) savanna–low temperature, precipitation uniform during the year
B) tundra–long summers, mild winters
C) temperate broadleaf forest–relatively short growing season, mild winters
D) temperate grasslands–relatively warm winters, most rainfall in summer
E) tropical forests–nearly constant day length and temperature






Answer: E

Which of the following is true with respect to oligotrophic lakes and eutrophic lakes?

Which of the following is true with respect to oligotrophic lakes and eutrophic lakes? 

A) Oligotrophic lakes are more subject to oxygen depletion.
B) Rates of photosynthesis are lower in eutrophic lakes.
C) Eutrophic lake water contains lower concentrations of nutrients.
D) Eutrophic lakes are richer in nutrients.
E) Sediments in oligotrophic lakes contain larger amounts of decomposable organic matter.






Answer: D

Which lake zone would be absent in a very shallow lake?

Which lake zone would be absent in a very shallow lake? 

A) benthic zone
B) aphotic zone
C) pelagic zone
D) littoral zone
E) limnetic zone





Answer: B

Which of the following areas of study focuses on the exchange of energy, organisms, and materials between ecosystems?

Which of the following areas of study focuses on the exchange of energy, organisms, and materials between ecosystems? 

A) population ecology
B) organismal ecology
C) landscape ecology
D) ecosystem ecology
E) community ecology





Answer: C

In areas of permafrost, stands of black spruce are frequently observed in the landscape, while other tree species are noticeably absent. Often these stands are referred to as "drunken forests" because many of the black spruce are displaced from their normal vertical alignment.

In areas of permafrost, stands of black spruce are frequently observed in the landscape, while other tree species are noticeably absent. Often these stands are referred to as "drunken forests" because many of the black spruce are displaced from their normal vertical alignment. 

What might be the adaptive significance of these unusual forests growing the way they do in this marginal habitat? 

A) Needles are adapted to withstand cold arctic temperatures.
B) Branches are adapted to absorb more CO2 with this displaced alignment.
C) Taproot formation is impossible, so trees developed shallow root beds.
D) Trees are tilted so snow prevents them from breaking or tipping over.
E) Trees tip so that they do not compete with each other for sunlight.






Answer: C

Experts in white-tailed deer ecology generally agree that population sizes of deer that live in temperate climates are limited by winter snow. The deer congregate in "yarding" areas under evergreen trees because venturing out to feed in winter is energetically too expensive when snowfall depths accumulate to above 40 cm. Deer often stay yarded until the spring thaw. Snow depth over 40 inches for more than 60 days results in high mortality due to starvation.

Experts in white-tailed deer ecology generally agree that population sizes of deer that live in temperate climates are limited by winter snow. The deer congregate in "yarding" areas under evergreen trees because venturing out to feed in winter is energetically too expensive when snowfall depths accumulate to above 40 cm. Deer often stay yarded until the spring thaw. Snow depth over 40 inches for more than 60 days results in high mortality due to starvation. 

This observation best illustrates which of the following principles about factors that limit distribution of organisms? 

A) Abiotic factors, such as weather extremes, ultimately limit distribution.
B) Organisms will face extinction unless they adapt to conditions or evolve new mechanisms for survival.
C) Environmental factors are limiting not only in amount but also in longevity.
D) Daily accumulations in snow depth gradually add up to cause increased deer mortality.
E) Temporary extremes in weather conditions usually result in high mortality in the deer population.




Answer: C

Studying species transplants is a way that ecologists

Studying species transplants is a way that ecologists 

A) determine the abundance of a species in a specified area.
B) determine the distribution of a species in a specified area.
C) develop mathematical models for distribution and abundance of organisms.
D) determine if dispersal is a key factor in limiting distribution of organisms.
E) consolidate a landscape region into a single ecosystem.






Answer: D

Trees are not usually found in the tundra biome because of

Trees are not usually found in the tundra biome because of 

A) insufficient annual precipitation.
B) acidic soils.
C) extreme winter temperatures.
D) overbrowsing by musk ox and caribou.
E) permafrost.







Answer: E

The growing season would generally be shortest in which of the following biomes?

The growing season would generally be shortest in which of the following biomes? 

A) savanna
B) temperate broadleaf forest
C) temperate grassland
D) tropical rain forest
E) coniferous forest






Answer: E

In which community would organisms most likely have adaptations enabling them to respond to different photoperiods?

In which community would organisms most likely have adaptations enabling them to respond to different photoperiods? 

A) tropical forest
B) coral reef
C) savanna
D) temperate forest
E) abyssal






Answer: D

Which of the following statements best describes the interaction between fire and ecosystems?

Which of the following statements best describes the interaction between fire and ecosystems? 

A) The likelihood of a wildfire occurring in a given ecosystem is highly predictable over the short term.
B) Many kinds of plants and plant communities have adapted to frequent fires.
C) The suppression of forest fires by man has prevented certain communities, such as grasslands, from reaching their climax stage.
D) Chaparral communities have evolved to the extent that they rarely burn.
E) Fire is unnatural in ecosystems and should be prevented.






Answer: B

Fire suppression by humans

Fire suppression by humans 

A) will always result in an increase in species diversity in a given biome.
B) can change the species composition within biological communities.
C) will result ultimately in sustainable production of increased amounts of forest products for human use.
D) is necessary for the protection of threatened and endangered forest species.
E) is a management goal of conservation biologists to maintain the healthy condition of forest communities.






Answer: B

In which of the following terrestrial biome pairs are both parts dependent upon periodic burning?

In which of the following terrestrial biome pairs are both parts dependent upon periodic burning? 

A) tundra and coniferous forest
B) chaparral and savanna
C) desert and savanna
D) tropical forest and temperate broadleaf forest
E) grassland and tundra






Answer: B

Two plant species live in the same biome but on different continents. Although the two species are not at all closely related, they may appear quite similar as a result of

Two plant species live in the same biome but on different continents. Although the two species are not at all closely related, they may appear quite similar as a result of 

A) parallel evolution.
B) convergent evolution.
C) allopatric speciation.
D) introgression.
E) gene flow.







Answer: B

In the development of terrestrial biomes, which factor is most dependent on all the others?

In the development of terrestrial biomes, which factor is most dependent on all the others? 

A) the species of colonizing animals
B) prevailing temperature
C) prevailing rainfall
D) mineral nutrient availability
E) soil structure





Answer: A

Which of the following statements best describes the effect of climate on biome distribution?

Which of the following statements best describes the effect of climate on biome distribution? 

A) Average annual temperature and precipitation are sufficient to predict which biome will be found in an area.
B) Seasonal fluctuation of temperature is not a limiting factor in biome distribution if areas have the same annual temperature and precipitation means.
C) Not only is the average climate important in determining biome distribution but so is the pattern of climatic variation.
D) Temperate forests and grasslands are different biomes because they receive a different quality and quantity of sunlight, even though they have essentially the same annual temperature and precipitation.
E) Correlation of climate with biome distribution is sufficient to determine the cause of biome patterns.






Answer: C

Species introduced by humans to new geographic locations

Species introduced by humans to new geographic locations 

A) are usually successful in colonizing the area.
B) always spread because they encounter none of their natural predators.
C) increase the diversity and therefore the stability of the ecosystem.
D) can outcompete and displace native species for biotic and abiotic resources.
E) are always considered pests by ecologists.





Answer: D

A certain species of pine tree survives only in scattered locations at elevations above 2,800 m in the western United States. To understand why this tree grows only in these specific places, an ecologist should

A certain species of pine tree survives only in scattered locations at elevations above 2,800 m in the western United States. To understand why this tree grows only in these specific places, an ecologist should 

A) conclude that lower elevations are limiting to the survival of this species.
B) study the anatomy and physiology of this species.
C) investigate the various biotic and abiotic factors that are unique to high altitude.
D) analyze the soils found in the vicinity of these trees, looking for unique chemicals that may support their growth.
E) collect data on temperature, wind, and precipitation at several of these locations for a year.






Answer: C

Which of the examples below provides appropriate abiotic and biotic factors that might determine the distribution of the species in question?

Which of the examples below provides appropriate abiotic and biotic factors that might determine the distribution of the species in question? 

A) the amount of nitrate and phosphate in the soil, and wildflower abundance and diversity
B) the number of frost-free days, and competition between species of introduced grasses and native alpine grasses
C) increased predation and decreased food availability, and a prairie dog population after a prairie fire
D) available sunlight and increased salinity in the top few meters of the ocean, and the abundance and diversity of phytoplankton communities
E) the pH and dissolved oxygen concentration, and the streams in which brook trout can live





Answer: B

If a meteor impact or volcanic eruption injected a lot of dust into the atmosphere and reduced the sunlight reaching Earth's surface by 70% for one year, which of the following marine communities most likely would be least affected?

If a meteor impact or volcanic eruption injected a lot of dust into the atmosphere and reduced the sunlight reaching Earth's surface by 70% for one year, which of the following marine communities most likely would be least affected? 

A) deep-sea vent
B) coral reef
C) intertidal
D) pelagic
E) estuary






Answer: A

Which of the following statements about the ocean pelagic biome is true?

Which of the following statements about the ocean pelagic biome is true? 

A) The ocean is a vast, deep storehouse that always provides sustenance; it is the next "frontier" for feeding humanity.
B) Because it is so immense, the pelagic ocean biome is globally uniform.
C) Globally, more photosynthesis occurs in the ocean neritic biome than in the pelagic biome.
D) Pelagic ocean photosynthetic activity is disproportionately low in relation to the size of the biome.
E) The most abundant animals are vertebrate fishes.






Answer: D

If you are interested in observing a relatively simple community structure in a clear water lake, you would do well to choose diving into

If you are interested in observing a relatively simple community structure in a clear water lake, you would do well to choose diving into 

A) an oligotrophic lake.
B) a eutrophic lake.
C) a relatively shallow lake.
D) a nutrient-rich lake.
E) a lake with consistently warm temperatures.




Answer: A

Which marine zone would have the lowest rates of primary productivity (photosynthesis)?

Which marine zone would have the lowest rates of primary productivity (photosynthesis)? 

A) pelagic
B) abyssal
C) neritic
D) continental shelf
E) intertidal





Answer: B

Imagine that a deep temperate zone lake did not "turn over" during the spring and fall seasons. Based on the physical and biological properties of limnetic ecosystems, what would be the difference from normal seasonal turnover?

Imagine that a deep temperate zone lake did not "turn over" during the spring and fall seasons. Based on the physical and biological properties of limnetic ecosystems, what would be the difference from normal seasonal turnover? 

A) The lake would be uniformly cold during the winter and summer.
B) The lake would fail to freeze over in winter.
C) An algal bloom of algae would result every spring.
D) Lakes would suffer a nutrient depletion in surface layers.
E) The pH of the lake would become increasingly alkaline.






Answer: D