Question 1

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.

Question 2

During exploitation,consumer organisms never cause their prey to become extinct.

Accepted Answer

A) True 
 B)False

Question 3

As shown in the following graph,selected intertidal communities along the Washington coast changed when the sea star Pisaster ochraceus was removed.After 10 years,how did those communities compare to control communities?

Accepted Answer

A)  The communities were statistically indistinguishable from one another. 
B)  Without sea stars,the total number of species declined. 
C)  Other predatory sea stars replaced Pisaster. 
D)  Some populations declined,but species diversity was unaffected.

Question 4

The release of a parasitic wasp in California helped control the infestation of scale insects on citrus trees.However,it also caused the near extinction of a different species of parasitic wasp.Should we consider this experiment an unqualified success?

Accepted Answer

A)  Yes;the scale insects are controlled,and the extinct wasp was not ecologically important. 
B)  Yes;as long as we get a result that helps humans,it does not matter what the effect is on other species. 
C)  No;the effect of the loss of the original species of wasp cannot be predicted and may be more significant than the benefits to the citrus tree crop. 
D)  No;the citrus tree population in California will now be able to rise to unmanageable numbers.

Question 5

Certain species of squirrels and acorn woodpeckers both eat acorns.In forests without squirrels,the density of acorn woodpeckers averages 100 per square kilometer,whereas in forests with squirrels,the density of acorn woodpeckers is roughly halved.This reduced density most probably results from

Accepted Answer

A)  interference competition. 
B)  herbivory. 
C)  character displacement. 
D)  exploitative competition.

Question 6

The consumer in a predator-prey interaction can be a selective force in the evolution of the prey species.

Accepted Answer

A) True 
 B)False

Question 7

During ________,a newly created habitat is inhabited.

Accepted Answer

A)  primary succession 
B)  climax community formation 
C)  disturbance colonization 
D)  keystone recovery

Question 8

Some species of warblers partition their niche by foraging in different parts of the same tree,although all birds eat the same species of insects and spiders.What mechanism has natural selection used to produce this interaction?

Accepted Answer

A)  character displacement 
B)  behavioral modification 
C)  directional selection 
D)  competitive exclusion

Question 9

By growing on the trunk or branch of a tree,a lichen gains height and exposure to sunlight for photosynthesis.The tree is not harmed by the lichen but does not benefit either.The relationship between the lichen and the tree is

Accepted Answer

A)  commensalism. 
B)  mutualism. 
C)  parasitism. 
D)  interference competition.

Question 10

Communities never recover from disturbances caused by humans.

Accepted Answer

A) True 
 B)False

Question 11

Burning of fossil fuels may affect climate but not communities.

Accepted Answer

A) True 
 B)False

Question 12

Which of the following best illustrates behavioral mutualism?

Accepted Answer

A)  Fruit seeds pass through a consumer's digestive system and are moved to a location distant from the parent plant. 
B)  Pollen from one plant is carried to another. 
C)  Small fish called cleaner wrasse remove parasites from the mouth and gills of predatory fish. 
D)  Infected individuals experience diarrhea that releases infectious organisms into the environment.

Question 13

Mistletoe participates in forest communities in many beneficial roles;its berries and leaves are food for herbivorous birds and insects,but to the trees that host it,mistletoe is strictly an undesirable ________.

Accepted Answer

The answer of Mistletoe participates in forest communities in many...

Question 14

The terms mutualistic and symbiotic can be used interchangeably;any mutualistic relationship is an example of symbiosis,whereas any symbiotic relationship is also mutualistic.

Accepted Answer

A) True 
 B)False

Question 15

Which of the following combinations of symbols represents an interaction in which one species benefits and the other is exploited?

Accepted Answer

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

Question 16

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.

Question 17

The bacteria in yogurt can colonize the human intestine and participate in a symbiotic relationship called ________.

Accepted Answer

The answer of The bacteria in yogurt can colonize the...

Question 18

Some algae and fungi live in associations known as lichens,which allow both to survive in a harsher environment than either could normally live in alone.This association is an example of

Accepted Answer

A)  parasitism. 
B)  mutualism. 
C)  consumerism. 
D)  competition.

Question 19

A praying mantis captures and devours many insects during its lifetime;the relationship between a mantis and the exploited species (for example,a grasshopper)is one of

Accepted Answer

A)  parasite/host. 
B)  pathogen/prey. 
C)  parasite/prey. 
D)  predator/prey.

Question 20

Which of the following patterns represents the outcomes of a mutualistic relationship?

Accepted Answer

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

Exam 23: Ecological Communities

Which of the following statements about communities is true?

During exploitation,consumer organisms never cause their prey to become extinct.

As shown in the following graph,selected intertidal communities along the Washington coast changed when the sea star Pisaster ochraceus was removed.After 10 years,how did those communities compare to control communities?

The release of a parasitic wasp in California helped control the infestation of scale insects on citrus trees.However,it also caused the near extinction of a different species of parasitic wasp.Should we consider this experiment an unqualified success?

Certain species of squirrels and acorn woodpeckers both eat acorns.In forests without squirrels,the density of acorn woodpeckers averages 100 per square kilometer,whereas in forests with squirrels,the density of acorn woodpeckers is roughly halved.This reduced density most probably results from

The consumer in a predator-prey interaction can be a selective force in the evolution of the prey species.

During ________,a newly created habitat is inhabited.

Some species of warblers partition their niche by foraging in different parts of the same tree,although all birds eat the same species of insects and spiders.What mechanism has natural selection used to produce this interaction?

By growing on the trunk or branch of a tree,a lichen gains height and exposure to sunlight for photosynthesis.The tree is not harmed by the lichen but does not benefit either.The relationship between the lichen and the tree is

Communities never recover from disturbances caused by humans.

Burning of fossil fuels may affect climate but not communities.

Which of the following best illustrates behavioral mutualism?

Mistletoe participates in forest communities in many beneficial roles;its berries and leaves are food for herbivorous birds and insects,but to the trees that host it,mistletoe is strictly an undesirable ________.

The terms mutualistic and symbiotic can be used interchangeably;any mutualistic relationship is an example of symbiosis,whereas any symbiotic relationship is also mutualistic.

Which of the following combinations of symbols represents an interaction in which one species benefits and the other is exploited?

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

The bacteria in yogurt can colonize the human intestine and participate in a symbiotic relationship called ________.

Some algae and fungi live in associations known as lichens,which allow both to survive in a harsher environment than either could normally live in alone.This association is an example of

A praying mantis captures and devours many insects during its lifetime;the relationship between a mantis and the exploited species (for example,a grasshopper) is one of

Which of the following patterns represents the outcomes of a mutualistic relationship?