Question 1

Consider the following segment of a food web:   Of these organisms, which is considered the primary consumer?

Accepted Answer

A)  Grass 
B)  Insect 
C)  Frog 
D)  Snake 
E)  Hawk 
A)  Grass 
B)  Insect 
C)  Frog 
D)  Snake 
E)  Hawk

Question 2

Tropical forest fig trees provide habitat for thousands of species of animals and are an important food source for many more.Animals that live in and feed on figs provide prey for the diversity of rainforest predators.These functions of fig trees suggest they can be considered a(n) _______ species.

Accepted Answer

The answer of Tropical forest fig trees provide habitat for...

Question 3

Would disturbance or stress be likely to have the most rapid effect on community structure?

Accepted Answer

A)  Disturbance, because disturbance always has a larger overall effect 
B)  Disturbance, because it injures or kills immediately, making room for other organisms 
C)  Stress, because it involves changes in reproduction and/or growth 
D)  Stress, because stress always results in stronger long-term effects 
E)  Either, depending on the individual situation 
A)  Disturbance, because disturbance always has a larger overall effect 
B)  Disturbance, because it injures or kills immediately, making room for other organisms 
C)  Stress, because it involves changes in reproduction and/or growth 
D)  Stress, because stress always results in stronger long-term effects 
E)  Either, depending on the individual situation

Question 4

Based on our current understanding of polycultures, an increase in stability of a community will likely lead to a(n) _______ in productivity of that system.

Accepted Answer

The answer of Based on our current understanding of polycultures,...

Question 5

A rancher wants to ensure that her cattle will get sufficient food by grazing on her grassland ecosystem every year, regardless of the year's temperature and precipitation levels.She knows that to ensure this, she must maintain high species diversity in the grassland.This is because high species diversity has all the following effects except

Accepted Answer

A)  making the ecosystem more stable, or more able to recover from disturbances. 
B)  using ecosystem resources more completely and efficiently. 
C)  ensuring that some species can persist even if the environment changes. 
D)  compensating for low abundance of one species with an increased abundance of another. 
E)  preventing any species from going extinct under extreme conditions. 
A)  making the ecosystem more stable, or more able to recover from disturbances. 
B)  using ecosystem resources more completely and efficiently. 
C)  ensuring that some species can persist even if the environment changes. 
D)  compensating for low abundance of one species with an increased abundance of another. 
E)  preventing any species from going extinct under extreme conditions.

Question 6

A community ecologist defined a rotting log in a forest as a community, and she set up a series of observations and experiments to study it.When defining this community, the researcher most likely considered all of the following aspects except that the log had a

Accepted Answer

A)  relatively distinct boundary. 
B)  specific number of species known in advance. 
C)  relatively distinct set of interacting species. 
D)  relatively self-contained food web. 
E)  size and location that could be easily studied. 
A)  relatively distinct boundary. 
B)  specific number of species known in advance. 
C)  relatively distinct set of interacting species. 
D)  relatively self-contained food web. 
E)  size and location that could be easily studied.

Question 7

The Shannon index of species diversity is calculated using this equation:   Habitat A has a total of 100 birds, with the following numbers of individuals per species: 20, 25, 20, 15, and 20.Habitat B also has 100 birds, with the following numbers of individuals per species: 80, 5, 5, 5, and 5.What is the Shannon index for habitat A?

Accepted Answer

A)  0 
B)  1.59 
C)  0.78 
D)  F1F1F1S1F1F1F100.78 
E)  0.32 
A)  0 
B)  1.59 
C)  0.78 
D)  F1F1F1S1F1F1F100.78 
E)  0.32

Question 8

As trees grow in a forest, they shade the understory plants, decreasing their ability to receive light and carry out photosynthesis.This is an example of _______.

Accepted Answer

The answer of As trees grow in a forest, they...

Question 9

Refer to the figure.   According to the intermediate disturbance hypothesis represented in the figure, species diversity in a community will be highest when the community

Accepted Answer

A)  is left undisturbed. 
B)  experiences high stress. 
C)  is moderately disturbed. 
D)  has little or no competition. 
E)  has a high likelihood of extinctions. 
A)  is left undisturbed. 
B)  experiences high stress. 
C)  is moderately disturbed. 
D)  has little or no competition. 
E)  has a high likelihood of extinctions.

Question 10

An ecologist creates a diagram showing the trophic interactions within a community.His diagram also includes information about competition, mutualism, and commensalism among species in the community.This diagram is best described as a(n) _______.

Accepted Answer

The answer of An ecologist creates a diagram showing the...

Question 11

A trophic cascade includes which kind(s) of interactions?

Accepted Answer

A)  Direct interactions only 
B)  Indirect interactions only 
C)  Both direct and indirect interactions 
D)  Abiotic interactions only 
E)  Both biotic and abiotic interactions 
A)  Direct interactions only 
B)  Indirect interactions only 
C)  Both direct and indirect interactions 
D)  Abiotic interactions only 
E)  Both biotic and abiotic interactions

Question 12

During succession at Glacier Bay, Dryas and alders carry out nitrogen fixation, helping spruce trees become established.Established spruce trees then compete for nutrients and light with other tree species, hindering them from becoming established.Should these two interactions be categorized as facilitation or inhibition?

Accepted Answer

A)  Both nitrogen fixation and spruce tree competition are facilitation. 
B)  Both nitrogen fixation and spruce tree competition are inhibition. 
C)  Nitrogen fixation is inhibition; spruce tree competition is facilitation. 
D)  Nitrogen fixation is facilitation; spruce tree competition is inhibition. 
E)  Categories cannot be determined from this information; each case must be considered individually. 
A)  Both nitrogen fixation and spruce tree competition are facilitation. 
B)  Both nitrogen fixation and spruce tree competition are inhibition. 
C)  Nitrogen fixation is inhibition; spruce tree competition is facilitation. 
D)  Nitrogen fixation is facilitation; spruce tree competition is inhibition. 
E)  Categories cannot be determined from this information; each case must be considered individually.

Question 13

The West Nile virus is carried by invasive Asian tiger mosquitoes and can infect humans.The Dutch elm fungus, spread by the invasive European elm bark beetle, as well as other elm bark beetles, has devastated elm tree populations in the northern United States.These two invasive species are similar in that both

Accepted Answer

A)  are viruses. 
B)  decrease species diversity. 
C)  cause diseases. 
D)  are fungi. 
E)  change native food webs. 
A)  are viruses. 
B)  decrease species diversity. 
C)  cause diseases. 
D)  are fungi. 
E)  change native food webs.

Question 14

Climate change is causing many species to move out of their present habitats into new habitats.These migrations are likely happening because of a change in

Accepted Answer

A)  the species' ability to disperse. 
B)  abiotic environmental conditions. 
C)  species interactions. 
D)  the species' ability to adapt. 
E)  the species' physiology. 
A)  the species' ability to disperse. 
B)  abiotic environmental conditions. 
C)  species interactions. 
D)  the species' ability to adapt. 
E)  the species' physiology.

Question 15

The ages of the moraines of Glacier Bay show the pattern of succession that has occurred there.On the oldest moraines, the communities are dominated by

Accepted Answer

A)  bacteria, fungi, and photosynthetic microorganisms. 
B)  willows and cottonwood trees. 
C)  Sitka spruce trees. 
D)  shrubby willows and alder trees. 
E)  lichens, mosses, and shrubs such as Dryas. 
A)  bacteria, fungi, and photosynthetic microorganisms. 
B)  willows and cottonwood trees. 
C)  Sitka spruce trees. 
D)  shrubby willows and alder trees. 
E)  lichens, mosses, and shrubs such as Dryas.

Question 16

In 1963, an oceanic volcanic eruption off the southern coast of Iceland formed the island of Surtsey.Given the process of primary succession, which organisms were likely the first to establish populations on the new island?

Accepted Answer

A)  Bacteria 
B)  Flies 
C)  Mosses 
D)  Flowering plants 
E)  Songbirds 
A)  Bacteria 
B)  Flies 
C)  Mosses 
D)  Flowering plants 
E)  Songbirds

Question 17

Coral reefs are found in shallow, coastal, tropical waters.Many species of organisms that might fit well in a coral reef community live some distance away.Which of these organisms would be most likely to colonize the coral reef?

Accepted Answer

A)  A sessile (nonmoving) species that lives and reproduces in one place 
B)  A species that is sessile as an adult but has a free-floating larval stage 
C)  A small, swimming species with a limited range 
D)  A large, schooling fish species that prefers the open ocean 
E)  A small species that needs to stay hidden throughout its life cycle 
A)  A sessile (nonmoving) species that lives and reproduces in one place 
B)  A species that is sessile as an adult but has a free-floating larval stage 
C)  A small, swimming species with a limited range 
D)  A large, schooling fish species that prefers the open ocean 
E)  A small species that needs to stay hidden throughout its life cycle

Question 18

Refer to the graph, showing the percentage of aspens added to the Yellowstone National Park forests each decade for a century, with and without the presence of wolves.   When present, wolves in the park feed on elk and control the elk population.Elk graze on aspen trees.Based on the graph, one can conclude that when wolves are not present to control the size of the elk population, aspen forests are

Accepted Answer

A)  not affected. 
B)  browsed heavily and disappear completely. 
C)  browsed heavily but rebound after wolves return. 
D)  browsed less and eventually recover. 
E)  browsed less but do not recover. 
A)  not affected. 
B)  browsed heavily and disappear completely. 
C)  browsed heavily but rebound after wolves return. 
D)  browsed less and eventually recover. 
E)  browsed less but do not recover.

Question 19

Consider the following segment of a food web:   If the removal of hawks from this part of the food web triggered a trophic cascade, what would be the effects, if any, on the population sizes of snakes and frogs?

Accepted Answer

A)  There would be no effects on either population. 
B)  Snakes and frogs would both increase. 
C)  Snakes and frogs would both decrease. 
D)  Snakes would increase and frogs would decrease. 
E)  Snakes would decrease and frogs would increase. 
A)  There would be no effects on either population. 
B)  Snakes and frogs would both increase. 
C)  Snakes and frogs would both decrease. 
D)  Snakes would increase and frogs would decrease. 
E)  Snakes would decrease and frogs would increase.

Question 20

Areas formed by volcanic activity, such as the Hawaiian Islands, have a lava substrate that is nitrogen-deficient.Many successful invaders in these areas are nitrogen fixers.By increasing nitrogen availability, these invaders enable the establishment of other invasive but non-nitrogen-fixing plant species.The changes to community structure result from _______.

Accepted Answer

The answer of Areas formed by volcanic activity, such as...

Exam 56: Communities

Consider the following segment of a food web: Of these organisms, which is considered the primary consumer?

Tropical forest fig trees provide habitat for thousands of species of animals and are an important food source for many more.Animals that live in and feed on figs provide prey for the diversity of rainforest predators.These functions of fig trees suggest they can be considered a(n) _______ species.

Would disturbance or stress be likely to have the most rapid effect on community structure?

Based on our current understanding of polycultures, an increase in stability of a community will likely lead to a(n) _______ in productivity of that system.

A community ecologist defined a rotting log in a forest as a community, and she set up a series of observations and experiments to study it.When defining this community, the researcher most likely considered all of the following aspects except that the log had a

As trees grow in a forest, they shade the understory plants, decreasing their ability to receive light and carry out photosynthesis.This is an example of _______.

Refer to the figure. According to the intermediate disturbance hypothesis represented in the figure, species diversity in a community will be highest when the community

An ecologist creates a diagram showing the trophic interactions within a community.His diagram also includes information about competition, mutualism, and commensalism among species in the community.This diagram is best described as a(n) _______.

A trophic cascade includes which kind(s) of interactions?

Climate change is causing many species to move out of their present habitats into new habitats.These migrations are likely happening because of a change in

The ages of the moraines of Glacier Bay show the pattern of succession that has occurred there.On the oldest moraines, the communities are dominated by

In 1963, an oceanic volcanic eruption off the southern coast of Iceland formed the island of Surtsey.Given the process of primary succession, which organisms were likely the first to establish populations on the new island?

Coral reefs are found in shallow, coastal, tropical waters.Many species of organisms that might fit well in a coral reef community live some distance away.Which of these organisms would be most likely to colonize the coral reef?

Consider the following segment of a food web: If the removal of hawks from this part of the food web triggered a trophic cascade, what would be the effects, if any, on the population sizes of snakes and frogs?

Studying Life

Small Molecules and the Chemistry of Life

Proteins, Carbohydrates, and Lipids

Nucleic Acids and the Origin of Life

Cells: the Working Units of Life

Cell Membranes

Cell Communication and Multicellularity

Energy, Enzymes, and Metabolism

Pathways That Harvest Chemical Energy

Photosynthesis: Energy From Sunlight

The Cell Cycle and Cell Division

Inheritance, Genes, and Chromosomes

Dna and Its Role in Heredity

From Dna to Protein: Gene Expression

Gene Mutation and Molecular Medicine

Regulation of Gene Expression

Genomes

Recombinant Dna and Biotechnology

Mechanisms of Evolution

Reconstructing and Using Phylogenies

Speciation

Evolution of Genes and Genomes

The History of Life on Earth

Bacteria, Archaea, and Viruses

The Origin and Diversification of Eukaryotes

Plants Without Seeds: From Water to Land

The Evolution of Seed Plants

The Evolution and Diversity of Fungi

Animal Origins and the Evolution of Body Plans

Protostome Animals

Deuterostome Animals

The Plant Body

Transport in Plants

Plant Nutrition

Regulation of Plant Growth

Reproduction in Flowering Plants

Plant Responses to Environmental Challenges

Physiology, Homeostasis, and Temperature Regulation

Animal Hormones

Immunology: Animal Defense Systems

Animal Reproduction

Animal Development

Neurons, Glia, and Nervous Systems

Sensory Systems

The Mammalian Nervous System: Structure and Higher Functions

Musculoskeletal Systems

Gas Exchange

Circulatory Systems

Nutrition, Digestion, and Absorption

Salt and Water Balance and Nitrogen Excretion

Animal Behavior

The Physical Environment and Biogeography of Life

Populations

Species Interactions

Ecosystems

A Changing Biosphere

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