Which of the following causes Earth's seasons?
global wind patterns
changes in the Earth's distance from the sun
vertical air circulation
ocean currents
Earth's tilt on its axis

Earth's tilt on its axis

Which of the following investigations is an example of the study of an abiotic factor?
identifying food sources for an egret population
investigating how the amount of annual precipitation affects the distribution of a tree species
investigating how an elk population competes for food
the relationship between finch beak size and food availability on two different Galapagos Islands
observing interactions among various organisms in a rainforest canopy

investigating how the amount of annual precipitation affects the distribution of a tree species

Which of the following might be an investigation of microclimate?

the effect of ambient temperature on the onset of caribou migration
how sunlight intensity affects plant community composition in the zone where a forest transitions into a meadow
competitive interactions among various species of songbirds during spring migration
the seasonal population fluctuation of nurse sharks in coral reef communities

how sunlight intensity affects plant community composition in the zone where a forest transitions into a meadow

In creating global climate patterns, which of the following factors is the primary cause of all of the other factors that are listed?

precipitation differences between tropical and polar regions
global wind patterns
variation in the heating of Earth's surface
global ocean currents

variation in the heating of Earth's surface

For mountain ranges that are subjected to prevailing winds, why is the climate drier on the leeward (downwind) side?

Deserts create dry conditions on the leeward side of mountain ranges.
Pushed by the prevailing winds on the windward side, air is forced to rise, cool, condense, and drop its precipitation, leaving drier air to descend the leeward side.
The sun illuminates the leeward side of mountain ranges at a more direct angle, converting to heat energy, which evaporates most of the water present.
Air masses pushed by the prevailing winds are stopped by mountain ranges and the moisture is used up in the stagnant air masses on the leeward side.

Pushed by the prevailing winds on the windward side, air is forced to rise, cool, condense, and drop its precipitation, leaving drier air to descend the leeward side.

Subtropical plants are commonplace in Land's End, England, whose latitude is the equivalent of Labrador in coastal Canada, where the local flora is instead subarctic. Which statement best explains why this apparent anomaly exists between North America and Europe?

-Rainfall fluctuates greatly in England; rainfall is consistently high in Labrador.
-Labrador receives sunlight of lower duration and intensity than does Land's End.
-Labrador does not get enough rainfall to support the subtropical flora found in Land's End.
-Warm ocean currents interact with England, whereas cold ocean currents interact with Labrador.

Warm ocean currents interact with England, whereas cold ocean currents interact with Labrador.

In mountainous areas of western North America, north-facing slopes would be expected to _____.

-receive more sunlight than similar southern exposures
-support biological communities similar to those found at higher elevations on similar south-facing slopes
-support biological communities similar to those found at lower elevations on similar south-facing slopes
-be warmer and drier than comparable southern exposed slopes

-support biological communities similar to those found at higher elevations on similar south-facing slopes

The main reason polar regions are cooler than the equator is that ________.

the poles are permanently tilted away from the sun
the poles are farther from the sun than is the equator
solar radiation strikes the poles at a lower angle and travels through more atmosphere
the polar atmosphere is thinner and contains fewer greenhouse gases

solar radiation strikes the poles at a lower angle and travels through more atmosphere

Generally speaking, deserts are located in places where air masses are usually ________.

descending
tropical
ascending
at the start of trade winds

descending

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

winds blowing from west to east along the equator
the elimination of ocean currents
a loss of seasonal variation at high latitudes
an elimination of deserts and increase in tropics

winds blowing from west to east along the equator

What are the two major factors determining the distribution of terrestrial biomes?

temperature and light
temperature and rainfall
light and rainfall
plants and animals
temperature and plants

temperature and rainfall

Which of these is the largest terrestrial biome on Earth?

tundra
coniferous forest
temperate broadleaf forest
temperate grassland
desert

coniferous forest

What is a biome?

a major type of ecosystem
a major type of biosphere
a set of similar communities
an area with a uniform distribution of organisms and abiotic environmental conditions
a specific set of abiotic factors

a major type of ecosystem

Which of the biomes—tundra, coniferous forest, temperate broadleaf forest, temperate grassland, savanna, chaparral, desert, tropical rainforest—require periodic fires to maintain their existence?

-savanna and chaparral
-savanna, chaparral, temperate grassland, tundra, and coniferous forest
-savanna, chaparral, temperate grassland, and coniferous forest
-savanna, desert, chaparral, temperate grassland, and temperate broadleaf forest
-tropical forest, savanna, chaparral, temperate grassland, and coniferous forest

-savanna, chaparral, temperate grassland, and coniferous forest

Which of the following biomes spans the largest annual mean temperature range, but the narrowest mean precipitation range?

tropical forest
desert
taiga
temperate forest

desert

If global warming continues at its present rate, which biomes will likely take the place of the coniferous forest (taiga)?

chaparral and temperate broadleaf forest
tropical forest and savanna
temperate broadleaf forest and grassland
desert and chaparral

temperate broadleaf forest and grassland

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

The suppression of forest fires by humans has prevented certain communities, such as grasslands, from reaching their climax stage.
Chaparral communities have evolved to the extent that they rarely burn.
Many kinds of plants and plant communities have adapted to frequent fires.
The likelihood of a wildfire occurring in a given ecosystem is highly predictable over the short term.

Many kinds of plants and plant communities have adapted to frequent fires.

Which of the following is an important feature of most terrestrial biomes?

vegetation demonstrating vertical layering
annual average rainfall in excess of 250 centimeters
clear boundaries between adjacent biomes
a distribution predicted almost entirely by rock and soil patterns

vegetation demonstrating vertical layering

Why are experiments that involve transplanting species seldom conducted today?

There are no criteria to determine if they are successful.
Species transplants still are a popular experimental tool.
The potential range of a transplanted species can never be greater than its actual range.
The success of the transplant cannot be measured in one researcher's lifetime.
The transplanted species are often disruptive to their new communities.

The transplanted species are often disruptive to their new communities.

Which would be a consequence of the removal of predators from a population such as the Trinidadian guppy population?
Primary producers such as algae would overgrow.
The nitrogen excretion rate would increase.
Guppy color patterns would change.
Guppies would produce fewer but larger offspring.
Guppy color patterns would change; guppies would produce fewer but larger offspring; the nitrogen excretion rate would increase and the rate of growth of primary producers such as algae would increase.

Guppy color patterns would change; guppies would produce fewer but larger offspring; the nitrogen excretion rate would increase and the rate of growth of primary producers such as algae would increase.

Which of the following examples demonstrate an ecological effect leading to an evolutionary effect?

A few individuals with denser fur survive the coldest years of an ice age, and the offspring of the reproducing survivors of the ice age will likely have more dense fur.
When seeds are not plentiful, trees produce more seeds.
Fish that swim the fastest in running water catch the most prey and more easily escape predation.
The insects that spend the most time exposed to sunlight have the most mutations from UV light, and thus evolve the fastest

A few individuals with denser fur survive the coldest years of an ice age, and the offspring of the reproducing survivors of the ice age will likely have more dense fur.

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

organismal ecology
population ecology
ecosystem ecology
community ecology
landscape ecology

landscape ecology

Which of the following is an example of a population?
the earthworms that live in a grassland plus the earthworms that live in a forest
all the coyotes on Earth
all of the redwood trees that live in a forest
a spider and the fly it is about to eat
all the plants that live near each other in a forest

all of the redwood trees that live in a forest

In wild populations, individuals most often show a _____ pattern of dispersion.

uniform
density-dependent
equilibrium
random
clumped

clumped

Suppose researchers marked 800 turtles and later were able to trap a total of 300 individuals in that population, of which 150 were marked. What is the estimate for total population size?

1,600
200
2,100
1,050

1,600

Which of the following assumptions must be made regarding the mark-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.

I only
II only
I and II only
I, II, and III

I, II, and III

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

competitive interaction between individuals of the same population
the concentration of nutrients within the population's range
patterns of high humidity
the random distribution of seeds

competitive interaction between individuals of the same population

Which of the following is the best natural example of a uniform pattern of dispersion?

moss spores floating in the wind to new locations of a forest
territorial songbirds in a mature forest during mating season
mushrooms growing on the floor of an old growth forest
bees collecting pollen in a wildflower meadow

mushrooms growing on the floor of an old growth forest

Starting from a single individual, what is the size of a population of bacteria at the end of a 2-hour time period if they reproduce by binary fission every 20 minutes?
128
32
16
64

64

During exponential growth, a population always ________.

quickly reaches its carrying capacity
loses some individuals to emigration
adds more new individuals when the population is small than when it is large
grows at its maximum per capita rate

grows at its maximum per capita rate

Which of the following is regarded as a density-independent factor in the growth of natural populations?
predation
flooding
intraspecific competition
emigration
interspecific competition

flooding

A broad-based pyramid-shaped age structure is characteristic of a population that is _____.
stable
limited by density-dependent factors
growing rapidly
at carrying capacity
shrinking

growing rapidly

Which of the following statements regarding the future of populations in developing, less industrialized countries are correct?

I) The reproductive rates are predicted to remain below replacement level.
II) Survivorship will increase.
III) Overall population size will increase dramatically.
IV) The fertility rate is predicted to remain high, especially in some regions.

only I and III
only II, III, and IV
only I, II, and III
only II and IV

only II, III, and IV

Humans who have pets tend to be healthier than humans who do not have pets. Which of these terms applies to the relationship between a human and a pet?

commensalism
competition
mutualism
predation
parasitism

mutualism

According to the principle of competitive exclusion, two species cannot continue to occupy the same _____.
range
territory
biome
ecological niche
environmental habitat

ecological niche

The term used to describe a harmless organism resembling a harmful one is _____.
Batesian mimicry
cryptic coloration
Müllerian mimicry
aposematic coloration
warning coloration

Batesian mimicry

What interactions exist between a lion pride and African wild dogs, if the dogs are found to typically avoid areas with lions?
+/-
+/+
-/-
0/0

+/-

Which fact is correct when describing species interactions?
+/0 will always remain such.
Species interactions occur in isolation and cannot affect the structure of ecological communities.
A -/- interaction benefits both of the species in the relationship.
A +/- interaction could shift to +/0 or +/+ over time, depending on other factors such as competition, population density, or environmental changes.

A +/- interaction could shift to +/0 or +/+ over time, depending on other factors such as competition, population density, or environmental changes.

An organism's "trophic level" refers to _____.
where it lives
its food source
the rate at which it uses energy
whether it is early or late in ecological succession
the intensity of its competition with other species

its food source

Keystone species are those species _____.
that provide important foods and medicines
that have the most biomass in the community
with the largest number of individuals in a community
whose absence would cause major disruption in a community
that live primarily on or under rocks and stones

whose absence would cause major disruption in a community

Elephants are not the most abundant species in African grasslands, yet they influence community structure. The grasslands contain scattered woody plants, but they are kept in check by the uprooting activities of the elephants. Take away the elephants, and the grasslands are converted to forests or to shrublands. The newly growing forests support fewer species than the previous grasslands. Which of the following statements describes why elephants are the keystone species in this scenario?

Elephants are the biggest herbivore in this community.
Elephants exhibit a disproportionate influence on the structure of the community relative to their abundance.
Elephants help other populations survive by keeping out many of the large African predators.
Grazing animals depend upon the elephants to convert forests to grassland.

Elephants exhibit a disproportionate influence on the structure of the community relative to their abundance.

Which of the following best illustrates ecological succession?

Grass grows on a sand dune, is replaced by shrubs, and then by trees.
A mouse eats seeds, and an owl eats the mouse.
Decomposition in soil releases nitrogen that plants can use.
Introduced pheasants increase, and native quail populations disappear.
Overgrazing causes a nutrient loss from soil.

Grass grows on a sand dune, is replaced by shrubs, and then by trees.

Why is a pathogen generally more virulent in a new habitat?

Pathogens evolve more efficient forms of reproduction in new environments.
Hosts in new environments have not had a chance to become resistant to the pathogen through natural selection.
New environments are almost always smaller in area so that transmission of pathogens is easily accomplished between hosts.
Intermediate host species are more motile and transport pathogens to new areas.

Hosts in new environments have not had a chance to become resistant to the pathogen through natural selection.

Caribbean coral reef communities have been strongly influenced by an unknown pathogen that causes white-band disease. How can the effect of white-band disease best be described?
a cascade event that shifts the entire makeup of the community
commensalism
the removal of a keystone species
mutualism
Batesian mimicry

a cascade event that shifts the entire makeup of the community

On a global scale, energy _____ ecosystems whereas chemical elements _____ ecosystems.
is biologically magnified in ... are recycled in
is dissipated in ... flow through
flows through ... are recycled in
is continuously supplied to ... are continuously removed from
is recycled in ... flow through

flows through ... are recycled in

Consider this segment of a food web: Snails and grasshoppers eat pepper plants; spiders eat grasshoppers; shrews eat snails and spiders; owls eat shrews. The shrew occupies the trophic level(s) of _____.
primary consumer only
secondary consumer only
tertiary consumer only
primary and secondary consumers
secondary and tertiary consumers

secondary and tertiary consumers

Which of the following terms encompasses all of the others?

primary consumers
heterotrophs
herbivores
carnivores

heterotrophs

In the ecosystem figure, which unit of the food web has the potential to lose the most energy as heat?
primary producers
microorganisms and other detritivores
secondary and tertiary consumers
primary consumers

primary producers

Examine this food web for a particular terrestrial ecosystem. Species C is toxic to predators. Which species is most likely to benefit from being a mimic of C?
A
B
C
E

B

Examine this food web for a particular terrestrial ecosystem. Which pair of species could be omnivores?
A and D
C and D
C and E
B and C

C and E

Which of the following organisms is correctly paired with its trophic level?

cyanobacterium: primary consumer
grasshopper: secondary consumer
phytoplankton: primary producer
fungus: primary consumer

phytoplankton: primary producer

The relationship between biomass and primary productivity is that _____.

biomass is the rate of primary productivity
biomass is the inverse of primary productivity
biomass is the natural log of primary productivity
primary productivity is the inverse of biomass
primary productivity is the rate at which biomass is produced

primary productivity is the rate at which biomass is produced

_____ are secondary consumers.

Producers
Herbivores
Plants
Cows
Carnivores

Carnivores

Which one of the following correctly ranks these organisms in order from lowest to highest percent in production efficiency?

fish, insects, mammals
mammals, insects, fish
insects, fish, mammals
mammals, fish, insects

mammals, fish, insects

Assume that, over a period of time, an owl consumes 5,000 J of animal material. The owl loses 2,300 J in feces and owl pellets and uses 2,500 J for cellular respiration. What is the production efficiency of this owl?
7.4%
40%
2%
8%

7.4%

Why does a vegetarian leave a smaller ecological footprint than an omnivore?

Fewer animals are slaughtered for human consumption.
There is an excess of plant biomass in all terrestrial ecosystems.
Vegetarians need to ingest less chemical energy than omnivores.
Eating meat is an inefficient way of acquiring photosynthetic productivity.

Eating meat is an inefficient way of acquiring photosynthetic productivity.

Which statement best describes what ultimately happens to the chemical energy that is consumed but not used to produce new biomass in the process of energy transfer between trophic levels in an ecosystem?

It is undigested and winds up in the feces and is not passed on to higher trophic levels.
It is used by organisms to maintain their life processes through the reactions of cellular respiration.
It is eliminated as feces or is dissipated into space as heat as a result of cellular respiration consistent with the second law of thermodynamics.
Heat produced by cellular respiration is used by heterotrophs for thermoregulation.

It is eliminated as feces or is dissipated into space as heat as a result of cellular respiration consistent with the second law of thermodynamics.

Detritus is composed of _____.

detritivores
dead organic matter
inorganic minerals
excreted wastes
dead organic matter and excreted wastes

dead organic matter and excreted wastes

Matter may be gained by, or lost from, ecosystems. How does this occur?

Heterotrophs convert heat to energy.
Chemoautotrophic organisms can convert matter to energy.
Photosynthetic organisms convert solar energy to sugars.
Matter can move from one ecosystem to another.

Matter can move from one ecosystem to another.

In contrast to bioremediation, which is a strategy for _____, biological augmentation _____ a degraded ecosystem.

-using organisms to add essential materials ... removes harmful substances from
-eradicating a crippling disease in a keystone species...involves planting fruit- and grain-bearing crops to provide more forage in
-replacing extirpated species... removes man-created pollutants and toxins from
-removing harmful substances...uses organisms to add essential materials to
-adding new species to control problem species...adds fertilizer to nutrient-poor soils in

-removing harmful substances...uses organisms to add essential materials to

The first step in ecosystem restoration is to _____.

restore native species that have been extirpated due to disturbance
restore the physical structure
remove competitive invasive species
remove toxic pollutants

restore the physical structure

Which of the following would be considered an example of bioremediation?

using a bulldozer to regrade a strip mine
adding nitrogen-fixing microorganisms to a degraded ecosystem to increase nitrogen availability
dredging a river bottom to remove contaminated sediments
adding fertilizer to soil poor in nutrients to increase plant growth

adding nitrogen-fixing microorganisms to a degraded ecosystem to increase nitrogen availability

Suppose that 60% of Earth’s species became extinct during a mass extinction. If you could survey Earth’s biological communities 10,000 years after the end of this mass extinction, which of the following would you most expect to find?

Food webs would show fewer connections and fewer trophic levels than before the extinction.
Net primary production (NPP) would be higher than before the extinction.
The number of species would have recovered to pre-extinction levels.
Species that were well adapted to conditions before the extinction would have survived.

Food webs would show fewer connections and fewer trophic levels than before the extinction.

Ecosystem services include processes that increase the quality of the abiotic environment. Which of the following processes would fall under this category?

Green plants and phytoplankton produce the oxygen we breathe.
Bees, flies, and wasps pollinate many plants.
The presence of dams improves flood control.
Keystone predators have a marked effect on species diversity.

Green plants and phytoplankton produce the oxygen we breathe.

Loss of biodiversity matters not only with regard to mammals or other vertebrates, but also microbes. Why are microbes worthy of discovery and protection from extinction?

Microbes play a role in digestion.
Microbes may be the most sensitive to the next large extinction event.
Microbes are much greater in species number than any other taxa on Earth.
Microbes may produce unique proteins useful in genetic research.

Microbes may produce unique proteins useful in genetic research

Overharvesting encourages extinction and is most likely to affect ________.

large animals with low intrinsic reproductive rates
most organisms that live in the oceans' coral reefs
edge-adapted species
animals that occupy a broad ecological niche

large animals with low intrinsic reproductive rates

Burning fossil fuels releases oxides of sulfur and nitrogen. These air pollutants can be responsible for ________.

the death of fish in lakes
precipitation with a pH as high as 8.0
eutrophication of lakes
global temperature decrease

the death of fish in lakes

Which of the following criteria have to be met for a species to qualify as invasive?

introduced to a new area, spreads rapidly, and displaces other invasive species
endemic to the area, spreads rapidly, and displaces foreign species
endemic to the area, spreads slowly, and displaces native species
introduced to a new area, spreads rapidly, and displaces native species

introduced to a new area, spreads rapidly, and displaces native species

Which of the following statements best describes why ecologists are currently concerned with global warming and the thawing of permafrost in many areas of the tundra biome?

Migratory species of birds will likely be less successful finding food in thawed tundra, and their abundance will drop dramatically.
Oil and coal deposits will thaw and rise to the surface (due to their lower density) of the tundra, destroying millions of acres of arctic habitat.
The thawing process will likely decrease the abundance and diversity of soil-dwelling organisms in the tundra.
Populations of humans inhabiting the Arctic will have to move to more southern latitudes, resulting in increased competition for resources in already densely populated areas.
The bacterial decomposition of thawed organic materials over the widespread areas of the tundra will produce large quantities of CO2, which will add to greenhouse gases and exacerbate global warming.

The bacterial decomposition of thawed organic materials over the widespread areas of the tundra will produce large quantities of CO2, which will add to greenhouse gases and exacerbate global warming.

The effort to develop, manage, and conserve Earth's resources to meet the needs of people today without limiting the ability of future generations to meet their needs is called _____.
landscape management
restoration ecology
bioremediation
biophilia
sustainable development

sustainable development