Question 1

Which of the following statements accurately describes an ecological community?

Accepted Answer

A) Communities have clearly fixed boundaries and are always defined on the same scale. 
B) Communities can be nested within a larger one. 
C) Communities are defined as groups of four or more species within a given area. 
D) Communities are groups of species that do not fluctuate over time. 
A) Communities have clearly fixed boundaries and are always defined on the same scale. 
B) Communities can be nested within a larger one. 
C) Communities are defined as groups of four or more species within a given area. 
D) Communities are groups of species that do not fluctuate over time. B

Question 2

A species of bat is removed from a community when it is hunted to extinction.Within two years scientists notice seeds from several plants are no longer germinating.The bat was a

Accepted Answer

A) community defining species. 
B) keystone species. 
C) primary consumer. 
D) producer. 
A) community defining species. 
B) keystone species. 
C) primary consumer. 
D) producer. B

Question 3

Follicle mites live in the hair follicles of human skin.They feed on single cells but do little if any harm to the human;the mite has a stable place to live and reproduce.This is an example of ________.

Accepted Answer

commensalism

Question 4

A "keystone" is defined in masonry as the stone at the top of an arch that holds the arch together.Using this definition and your knowledge of keystone species,explain how the role of a keystone species within an ecological community is analogous to the keystone within an arch.

Accepted Answer

A keystone species holds an ecological c

Question 5

The sea star Pisaster ochraceus is a keystone species.Ten years after P.ochraceus is removed from selected intertidal communities along the Washington coast,how might those communities compare to control communities?

Accepted Answer

A) The communities would be statistically indistinguishable from one another. 
B) Sea star prey,such as mussels might increase in abundance and crowd out other community members. 
C) Other predators will simply replace P.ochraceus and take advantage of prey that P.ochraceus consumed. 
D) Prey species,such as mussels would decline,but most species within the community would be unaffected. 
A) The communities would be statistically indistinguishable from one another. 
B) Sea star prey,such as mussels might increase in abundance and crowd out other community members. 
C) Other predators will simply replace P.ochraceus and take advantage of prey that P.ochraceus consumed. 
D) Prey species,such as mussels would decline,but most species within the community would be unaffected.

Question 6

An ecological ________ is an association of populations of different species that live in the same area.

Accepted Answer

The answer of An ecological ________ is an association of...

Question 7

Which of the following symbols represents a mutualistic relationship?

Accepted Answer

A) +/- 
B) +/+ 
C) o/+ 
D) -/- 
A) +/- 
B) +/+ 
C) o/+ 
D) -/-

Question 8

Which of the following statements about communities is true?

Accepted Answer

A) They usually have few species of organisms. 
B) There can be complex interactions between the organisms that make up a community. 
C) They are more abundant in temperate areas. 
D) They are made up of mammal species only. 
A) They usually have few species of organisms. 
B) There can be complex interactions between the organisms that make up a community. 
C) They are more abundant in temperate areas. 
D) They are made up of mammal species only.

Question 9

Which of the following choices best explains,from an ecological perspective,why there are laws that require a wildlife survey before certain building or other land-use projects may proceed?

Accepted Answer

A) If a keystone species is found,it can be moved to another area where it will establish a new community of organisms. 
B) If the only local habitat for a keystone species is disturbed,the entire community of populations will be affected. 
C) If the species are surveyed before the land is used,they will all be more likely to survive the building project. 
D) If the species are surveyed before the land is used,they will all be more easily distributed to other habitats. 
A) If a keystone species is found,it can be moved to another area where it will establish a new community of organisms. 
B) If the only local habitat for a keystone species is disturbed,the entire community of populations will be affected. 
C) If the species are surveyed before the land is used,they will all be more likely to survive the building project. 
D) If the species are surveyed before the land is used,they will all be more easily distributed to other habitats.

Question 10

Communities change with respect to several timescales.An example of long-term change would be the

Accepted Answer

A) annual variability in population size. 
B) presence or absence of a migrant species. 
C) species composition of the community. 
D) decline in prey abundance during a harsh winter. 
A) annual variability in population size. 
B) presence or absence of a migrant species. 
C) species composition of the community. 
D) decline in prey abundance during a harsh winter.

Question 11

In a typical prairie food web,energy moves from grass to grasshopper to field mouse to fox.Which organism is the secondary consumer?

Accepted Answer

A) the grass 
B) the grasshopper 
C) the mouse 
D) the fox 
A) the grass 
B) the grasshopper 
C) the mouse 
D) the fox

Question 12

In ________ competition,species compete indirectly for a shared resource,each reducing the amount available to the other competitor.

Accepted Answer

A) exploitative 
B) restrictive 
C) interference 
D) advantageous 
A) exploitative 
B) restrictive 
C) interference 
D) advantageous

Question 13

Which of the following can occur when the climate of an area changes?

Accepted Answer

A) Natural selection usually causes the community to adapt and survive the change with little visible effect. 
B) That area becomes uninhabitable to all species and is abandoned. 
C) That community may relocate to an area with a climate similar to that of the original location. 
D) Continental drift restores communities to climates similar to those from which the communities came. 
A) Natural selection usually causes the community to adapt and survive the change with little visible effect. 
B) That area becomes uninhabitable to all species and is abandoned. 
C) That community may relocate to an area with a climate similar to that of the original location. 
D) Continental drift restores communities to climates similar to those from which the communities came.

Question 14

If a disease quickly spreads through a desert and kills moths that are the sole pollinators of long-lived yucca plants,the most likely outcome would be

Accepted Answer

A) another pollinator would quickly take over and begin to pollinate the yucca plants. 
B) the yucca plants would self-pollinate. 
C) the yucca plants would die the season after the last yucca moth died. 
D) the yucca plants would not be pollinated and would eventually go extinct. 
A) another pollinator would quickly take over and begin to pollinate the yucca plants. 
B) the yucca plants would self-pollinate. 
C) the yucca plants would die the season after the last yucca moth died. 
D) the yucca plants would not be pollinated and would eventually go extinct.

Question 15

Why is the existence of food webs important even though food chains also exist?

Accepted Answer

A) Food webs address the activities of consumers,whereas food chains address the activities of producers. 
B) Food chains describe all aspects of interactions within a community,whereas food webs tell us what organisms eat and which are eaten by other organisms. 
C) Food webs are smaller groupings than food chains.Food chains allow us to look at the overall picture,whereas food webs provide specific directional information. 
D) Food webs tie together many more organisms than a food chain does.If one organism in a food chain disappears,a food web may allow the organisms in the chain to survive based on their interactions with other organisms. 
A) Food webs address the activities of consumers,whereas food chains address the activities of producers. 
B) Food chains describe all aspects of interactions within a community,whereas food webs tell us what organisms eat and which are eaten by other organisms. 
C) Food webs are smaller groupings than food chains.Food chains allow us to look at the overall picture,whereas food webs provide specific directional information. 
D) Food webs tie together many more organisms than a food chain does.If one organism in a food chain disappears,a food web may allow the organisms in the chain to survive based on their interactions with other organisms.

Question 16

In which of the following situations would you expect succession to take the longest?

Accepted Answer

A) A volcanic island forms far from any mainland. 
B) A forest fire burns 1,200 acres in Texas. 
C) Sand dunes form a new island within a half mile of a mainland. 
D) Humans log an area and then burn remaining undergrowth. 
A) A volcanic island forms far from any mainland. 
B) A forest fire burns 1,200 acres in Texas. 
C) Sand dunes form a new island within a half mile of a mainland. 
D) Humans log an area and then burn remaining undergrowth.

Question 17

All of the following disturbances EXCEPT ________ would be considered natural.

Accepted Answer

A) fire 
B) flood 
C) windstorm 
D) mining 
A) fire 
B) flood 
C) windstorm 
D) mining

Question 18

The figure shown illustrates how,although pines first established themselves as the dominant tree in the Lake Michigan sand dune community,black oaks ultimately become the dominant species.What best explains the gradual reduction of the pine?

Accepted Answer

A) Oaks trap sand,causing the dune to level out;pines can only survive in the low,protected areas between the dunes. 
B) Pine needles and the shade from existing pines improve the soil composition and moisture,allowing oaks to become established and preventing new pines from surviving. 
C) Pines replace the grasses but this destabilizes the dune and increases the amount of moving sand.The loss of pines is not related to the presence of the oaks. 
D) Actually oak seeds were always present in the sand;they simply require more time to germinate. 
A) Oaks trap sand,causing the dune to level out;pines can only survive in the low,protected areas between the dunes. 
B) Pine needles and the shade from existing pines improve the soil composition and moisture,allowing oaks to become established and preventing new pines from surviving. 
C) Pines replace the grasses but this destabilizes the dune and increases the amount of moving sand.The loss of pines is not related to the presence of the oaks. 
D) Actually oak seeds were always present in the sand;they simply require more time to germinate.

Question 19

Which of the following best explains why a grass species might disappear when a meat-eating species is removed from a community?

Accepted Answer

A) The meat-eating species protects grass directly as a way to provide cover for themselves while stalking their prey. 
B) The grass seeds are dispersed by meat eaters who travel long distances and deposit grass seeds in their feces. 
C) The meat-eating species eats organisms that eat grass.Removing the meat-eater allows an increase in the abundance of grass-eating organisms. 
D) The loss of meat-eaters from a community typically causes drastic changes in the physical environment that prevent grasses from sprouting. 
A) The meat-eating species protects grass directly as a way to provide cover for themselves while stalking their prey. 
B) The grass seeds are dispersed by meat eaters who travel long distances and deposit grass seeds in their feces. 
C) The meat-eating species eats organisms that eat grass.Removing the meat-eater allows an increase in the abundance of grass-eating organisms. 
D) The loss of meat-eaters from a community typically causes drastic changes in the physical environment that prevent grasses from sprouting.

Question 20

The general process by which species in a community are replaced over time is called ________.

Accepted Answer

The answer of The general process by which species in...

Which of the following statements accurately describes an ecological community?

A species of bat is removed from a community when it is hunted to extinction.Within two years scientists notice seeds from several plants are no longer germinating.The bat was a

Follicle mites live in the hair follicles of human skin.They feed on single cells but do little if any harm to the human;the mite has a stable place to live and reproduce.This is an example of ________.

A "keystone" is defined in masonry as the stone at the top of an arch that holds the arch together.Using this definition and your knowledge of keystone species,explain how the role of a keystone species within an ecological community is analogous to the keystone within an arch.

The sea star Pisaster ochraceus is a keystone species.Ten years after P.ochraceus is removed from selected intertidal communities along the Washington coast,how might those communities compare to control communities?

An ecological ________ is an association of populations of different species that live in the same area.

Which of the following symbols represents a mutualistic relationship?

Which of the following statements about communities is true?

Which of the following choices best explains,from an ecological perspective,why there are laws that require a wildlife survey before certain building or other land-use projects may proceed?

Communities change with respect to several timescales.An example of long-term change would be the

In a typical prairie food web,energy moves from grass to grasshopper to field mouse to fox.Which organism is the secondary consumer?

In ________ competition,species compete indirectly for a shared resource,each reducing the amount available to the other competitor.

Which of the following can occur when the climate of an area changes?

If a disease quickly spreads through a desert and kills moths that are the sole pollinators of long-lived yucca plants,the most likely outcome would be

Why is the existence of food webs important even though food chains also exist?

In which of the following situations would you expect succession to take the longest?

All of the following disturbances EXCEPT ________ would be considered natural.

The figure shown illustrates how,although pines first established themselves as the dominant tree in the Lake Michigan sand dune community,black oaks ultimately become the dominant species.What best explains the gradual reduction of the pine?

Which of the following best explains why a grass species might disappear when a meat-eating species is removed from a community?

The general process by which species in a community are replaced over time is called ________.

The Nature of Science

Chemistry of Life

Life Is Cellular

How Cells Work

Cell Division

Patterns of Inheritance

Chromosomes and Human Genetics

What Genes Are

How Genes Work

Evidence for Evolution

Mechanisms of Evolution

Adaptation and Species

The History of Life

Human Evolution

General Principles of Ecology

Growth of Populations

Ecosystems

Applying the Science

Filters

Exam 17: Communities of Organisms

Which of the following statements accurately describes an ecological community?

A species of bat is removed from a community when it is hunted to extinction.Within two years scientists notice seeds from several plants are no longer germinating.The bat was a

Follicle mites live in the hair follicles of human skin.They feed on single cells but do little if any harm to the human;the mite has a stable place to live and reproduce.This is an example of ________.

A "keystone" is defined in masonry as the stone at the top of an arch that holds the arch together.Using this definition and your knowledge of keystone species,explain how the role of a keystone species within an ecological community is analogous to the keystone within an arch.

The sea star Pisaster ochraceus is a keystone species.Ten years after P.ochraceus is removed from selected intertidal communities along the Washington coast,how might those communities compare to control communities?

An ecological ________ is an association of populations of different species that live in the same area.

Which of the following symbols represents a mutualistic relationship?

Which of the following statements about communities is true?

Which of the following choices best explains,from an ecological perspective,why there are laws that require a wildlife survey before certain building or other land-use projects may proceed?

Communities change with respect to several timescales.An example of long-term change would be the

In a typical prairie food web,energy moves from grass to grasshopper to field mouse to fox.Which organism is the secondary consumer?

In ________ competition,species compete indirectly for a shared resource,each reducing the amount available to the other competitor.

Which of the following can occur when the climate of an area changes?

If a disease quickly spreads through a desert and kills moths that are the sole pollinators of long-lived yucca plants,the most likely outcome would be

Why is the existence of food webs important even though food chains also exist?

In which of the following situations would you expect succession to take the longest?

All of the following disturbances EXCEPT ________ would be considered natural.

The figure shown illustrates how,although pines first established themselves as the dominant tree in the Lake Michigan sand dune community,black oaks ultimately become the dominant species.What best explains the gradual reduction of the pine?

Which of the following best explains why a grass species might disappear when a meat-eating species is removed from a community?

The general process by which species in a community are replaced over time is called ________.

The Nature of Science

Chemistry of Life

Life Is Cellular

How Cells Work

Cell Division

Patterns of Inheritance

Chromosomes and Human Genetics

What Genes Are

How Genes Work

Evidence for Evolution

Mechanisms of Evolution

Adaptation and Species

The History of Life

Human Evolution

General Principles of Ecology

Growth of Populations

Ecosystems

Applying the Science

Filters