DFF Ecology

Which of the following is a hypothesis generated by biologists to explain species richness gradients? a. Greater competition in the tropics has led to narrower niches and thus more species in the tropics than elsewhere. b.The lack of mutualisms in the higher latitudes limits the number of species in high latitude communities. c. Intense predation in the polar regions limits the number of species that can live there. d. The presence of mountain ranges and expanses of coastline in higher latitudes limit species richness. e. The lack of pathogenic organisms in the tropics promotes species richness.

a. Greater competition in the tropics has led to narrower niches and thus more species in the tropics than elsewhere.

Earth's axis is tilted by 23.5 degrees. If the axis were to become tilted by only 10 degrees, what would be the most likely change in Earth's climate? a. The North and South poles would have warmer annual average temperatures. b. The equator would have a colder annual average temperature. c. Tropical climates would spread over a larger area of the continents. d. Winters would become more severe in the southern hemisphere and less severe in the northern hemisphere. e. Air would circulate more quickly in the atmosphere, resulting in stronger surface winds.

a. The North and South poles would have warmer annual average temperatures.

The sun's rays are most concentrated at the equator and least concentrated at the poles. What is the main reason for this difference in solar intensity? a. The sun strikes Earth directly near the equator and at an angle near the poles. b. Day length is always shorter at the poles than it is at the equator. c. The equator is closer to the sun than the poles are. d. Earth's land masses are clustered nearer to the equator than to the poles. e. Earth rotates on its axis every 24 hours.

a. The sun strikes Earth directly near the equator and at an angle near the poles.

Which of the following statements about disturbances is false? a. They are always caused by biotic factors. b. They can be beneficial to some species. c. They can be caused by keystone species. d. Small disturbances are more common than large ones, but large disturbances have a greater overall effect. e. Disturbances may eliminate some species.

a. They are always caused by biotic factors.

Primary producers receive their energy a. from the sun. b. from minerals in the soil. c. by consuming plants. d. by consuming animals. e. by decomposing waste products.

a. from the sun

At the equator, _______ air masses _______, which causes them to _______ and _______ moisture. a. warm; rise; cool; lose b. warm; rise; cool; gain c. cool; rise; warm; lose d. cool; rise; warm; gain e. cool; fall; warm; gain

a. warm; rise; cool; lose

Primary consumers

animals that feed on primary producers; ex. herbivores

_______ energy drives global climates. a. Geothermal b. Solar c. Hydro d. Wind e. Volcanic

b. Solar

Stinging bees, stinging wasps, and nonstinging hover flies all have black and yellow striped abdomens. Which of the following statements about mimicry is true in the case of these insects? a. The bee and the fly are Müllerian mimics, and the wasp is a Batesian mimic. b. The bee and the wasp are Müllerian mimics, and the fly is a Batesian mimic. c. The bee and the wasp are Batesian mimics, and the fly is a Müllerian mimic. d. All three insects are Müllerian mimics. e. All three insects are Batesian mimics.

b. The bee and the wasp are Müllerian mimics, and the fly is a Batesian mimic.

Which of the following topics would not be studied in ecology? a. The dispersal of plant seeds by bats b. The molecular structure of the lipids in plant seeds c. How frequent fires affect the diversity of plants d. Whether an invasive ant species interferes with native ant species e. What kinds of insects pollinate geranium flowers

b. The molecular structure of the lipids in plant seeds

For most communities, species richness will _______ if fertilizer is added when productivity is low, and it will _______ if fertilizer is added when productivity is high. a. increase; increase b. increase; decrease c. remain the same; increase d. decrease; increase e. decrease; decrease

b. increase; decrease

Consider a food chain in which hawks eat snakes eat frogs eat insects eat plants. If the removal of hawks from this food chain triggered a trophic cascade, what would be the effects, if any, on the population sizes of snakes and frogs? a. no effects on the snake and frog populations b. snakes increase, frogs decrease c. snakes decrease, frogs increase d. snakes and frogs both increase e. snakes and frogs both decrease

b. snakes increase, frogs decrease

Mutualism

both species benefit

Although most herbivory involves an antagonistic interaction, some herbivorous interactions do not. Which of the following is not an antagonistic interaction? a. Aphids pierce stems and consume plant sap, but they do not damage other plant parts. b. Nematodes feed on the starches in plant roots; the roots live but their growth is slowed. c. Bears eat blueberries; then they defecate the blueberry seeds throughout the forest, and the seeds germinate. d. Gypsy moth caterpillars feed on the leaves of oak and aspen, defoliating and stressing the trees. e. Leaf miner insects feed on sugars in leaf cells without killing the leaves.

c. Bears eat blueberries; then they defecate the blueberry seeds throughout the forest, and the seeds germinate.

Researchers in Kenya used exclosures to investigate the influence of large grazing mammals on the savannah community. In comparing the exclosed communities to the open control sites, they found that trees, insects, and insectivorous lizards were all more abundant within the exclosures. Use these results to predict how the reintroduction of wolves into Yellowstone National Park should affect the abundances of beetle herbivores of aspens. a. There should be no correlation between wolf and beetle populations. b. Beetle populations should first increase, then decrease. c. Beetle populations should increase. d. Beetle populations should decrease. e. Beetle populations should be held steady.

c. Beetle populations should increase.

Which of the following statements about species richness is true? a. It is highest in the temperate zones of both hemispheres. b. It is highest in the northern temperate zone, followed by the tropics, followed by the southern temperate zone. c. It is highest in the tropics. d. It is highest in the southern temperate zone, followed by the tropics, followed by the northern temperate zone. e. It is equally high in the temperate zones and in the tropics.

c. It is highest in the tropics.

The island biogeography theory addresses a. the evolution of endemic species. b. the latitudinal gradient of species richness. c. species-area relationships. d. diversity on volcanic versus coral reef islands. e. the effects of human colonization on diversity.

c. species-area relationships.

The appearance of a physical barrier that splits the range of a species is called a(n) a. environmental block. b. divider event. c. vicariant event. d. physical succession event. e. range inhibitor.

c. vicariant event

Crypsis

camouflage

The species that live and interact in a particular area constitute an ecological _______ .

community

Resource partitioning

competing species change the way they use shared resource

interspecific competition

competition between members of different species outcomes: same as intraspecific - decreased growth and reproductive rates, may exclude some individuals from better habitats, may cause deaths

intraspecific competition

competition between members of the same species outcomes: decreased growth and reproductive rates, may exclude some individuals from better habitats, may cause deaths

Which of the following statements about island biogeography is false? a. Major disturbances can serve as "natural experiments" that allow researchers to estimate colonization rates. b. Island biogeography theory predicts that when species numbers are above the equilibrium, extinction rates will increase. c. Island biogeography theory predicts that when species numbers are far below the equilibrium, immigration rates will increase. d. Island biogeography theory is particularly concerned with the identity of species found on particular islands. e. Island biogeography theory is based on the premise that species richness on an island represents a balance between the rate of species immigration and the rate of local species extinction.

d. Island biogeography theory is particularly concerned with the identity of species found on particular islands.

In the world's oceans, which of the following physical features is most closely associated with the largest numbers and diversity of organisms? a. Large volume b. Geothermal vents c. Warm waters d. Presence of light e. Stable salinities

d. Presence of light

Despite being so low in abundance that it is classified as a "near threatened" species, the jaguar plays an important role in structuring forest communities. It is thus considered a(n) _______ species.

keystone

Commensalism

one benefits and the other is unaffected ex: one species feeding near another

Ammensalism

one is harmed, the other is unaffected ex: stepping on a bug

Antagonistic interactions

one species benefits and the other is harmed -Predation -Herbivory -Parasitism

competitive exclusion

one species prevents all members of another from using a shared resource, other species may go extinct

Logistic growth model

population reaches a carrying capacity

Trophic levels

primary producers, primary consumers, secondary consumers, tertiary consumers, detrivores/decomposers

r-strategist

reproduce early in life; many small unprotected offspring

K strategist

reproduce late in life; few offspring; care for offspring

Aposematism

warning coloration of toxic species

Density-independent limits on population growth

Affect growth rate independent of density Tend to be abiotic Cause abrupt/erratic changes in population size - Extreme weather - Natural disasters

Density-dependent limits on population growth

Affect growth rate with increasing density Tend to be biotic Lead to logistic growth (maintain/correct a population size) - Competition (food supply) - Predators - Pathogens - Waste accumulation

Primary producers

Autotroph, usually photosynthetic (energy source = sunlight) Make up the trophic level of an ecosystem that ultimately supports all other levels.

oligophagous herbivores

Majority of herbivores Eat just one species or a few related species

Mullerian mimicry

Multiple aposematic species converge on a common color pattern

Predict the effects of the removal of a top predator on a community

Population explosion of prey species Trophic cascade -Herbivorous prey species reproduce w/o check -More herbivores eat more plants, plant population decreases Behavioral changes in prey species Population sickness and migration

Secondary consumers

Primary carnivores Eat primary consumers (herbivores)

Tertiary consumers

Secondary carnivores Eat secondary consumers

Batesian mimicry

A type of mimicry in which a harmless species looks like a species that is poisonous or otherwise harmful to predators.

Competition

2+ species use the same resource

Describe climatological and geographical factors that limit species' ranges

Climate - Temperature (solar radiation) - Water availability (rain, seasons) Geography - Biomes?

When two populations of flour beetles, the red flour beetle and the confused flour beetle, occur together in the same bag of flour, the red flour beetle population usually increases and the confused flour beetle population dwindles in number until no confused flour beetles remain. This type of outcome between species that use the same limited resource is called _______ .

Competitive exclusion

Exponential growth model

Constant birth and death rate Unlimited access to resources -> unlimited growth

Prey species defenses

Crypsis Aposematism Batesian mimicry Mullerian mimicry

Polyphagous herbivores

Eat many species Most vertebrate herbivores

Detrivores/decomposer

Eat waste matter and dead tissue

Both beavers and ochre sea stars exert profound effects on their communities. Beavers create ecosystems by damming up streams to build ponds. Sea stars increase community richness by preying on mussels, thus making room for competitors of mussels to live in the rocky intertidal zone. Based on these effects, which of the following statements is true? a. The beaver and the sea star are keystone species and ecosystem engineers. b. The beaver and the sea star are keystone species but are not ecosystem engineers. c. The beaver and the sea star are ecosystem engineers but not keystone species. d. The beaver is a keystone species and an ecosystem engineer; the sea star is a keystone species but not an ecosystem engineer. e. The beaver is a keystone species but not an ecosystem engineer; the sea star is a keystone species and an ecosystem engineer.

d. The beaver is a keystone species and an ecosystem engineer; the sea star is a keystone species but not an ecosystem engineer.

Two species of beetles are herbivores on the same host plant, and the presence of either species reduces the population growth of the other. The relationship between the beetles is therefore best described as a. antagonistic. b. predation. c. herbivory. d. competition. e. amensalism.

d. competition

As productivity increases, species richness in a community a. generally increases. b. generally decreases. c. stays relatively flat. d. increases at first and then decreases. e. decreases at first and then increases.

d. increases at first and then decreases.

Which of the following is the correct chronological order (from earliest to latest) for the succession of species in Glacier Park? a. Alders → spruces → lichens b. Spruces → alders → lichens c. Spruces → lichens → alders d. Lichens → spruces → alders e. Lichens → alders → spruces

e. Lichens → alders → spruces

Which of the following would be considered an abiotic factor in the environment? a. Predators b. Parasites c. Competitors d. Prey e. Oxygen

e. Oxygen

Which of the following biomes has the greatest species richness? a. Thorn forest b. Boreal forest c. Tropical deciduous forest d. Temperate deciduous forest e. Tropical evergreen forest

e. Tropical evergreen forest

Biogeographers determine the roles of vicariance and dispersal when reconstructing the evolutionary history of a particular distribution by a. studying area phylogenies. b. applying the parsimony principle. c. understanding the geologic events of the area. d. a and b only e. a, b, and c

e. a, b, and c

The number of trophic levels in most communities is limited by a. the presence of decomposers. b. loss of prey due to predation. c. competitive exclusion. d. changes in which species are present due to succession. e. the loss of energy between trophic levels.

e. the loss of energy between trophic levels.