Question 1

All of these factors reduce the efficiency of energy transfer between trophic levels except

Accepted Answer

A)   heat loss due to maintaining homeostasis.
B)   heat loss due to metabolism.
C)   indigestibility of some biomass.
D)   biomass stored as fat or starch.
E)   lack of availability of some biomass. D

Question 2

The colonization rate of beetles on an island currently averages three new beetle species per year and the extinction rate averages one beetle species per year.Assuming the island conforms to the theory of island biogeography,species richness is currently (lower than/higher than/the same as)_______ the species richness at equilibrium.

Accepted Answer

lower than

Question 3

Suppose a business in an urban area is closed.Its buildings are torn down and the land is left abandoned.Describe what will happen to this area over time,and what ecological principles will be at work.

Accepted Answer

The area will undergo succession.A barren area is open to colonization by any organisms present in the immediate area (or flying over);as time passes,the area will build soil and ground cover.There will be a constant turnover of species,and species diversity will increase.Eventually weeds,grasses,and shrubs,including flowering plants,will invade,along with insects and larger urban animals.

Question 4

Refer to the figure below.The graph at right shows the number of swallowtail butterfly species at various latitudes,with relative locations shown on the map at left.Using this information,briefly explain the relationship between species richness and latitude,and give at least two possible reasons for this relationship.

Accepted Answer

The answer of Refer to the figure below.The graph at...

Question 5

A large flowerbed is designed to attract pollinators such as bees,butterflies,and hummingbirds.It contains a variety of plants of different heights-shrubs,forbs,and annuals-with flowers that bloom at different seasons.The pollinators are most likely attracted to the flowerbed because of its complex

Accepted Answer

A)   species turnover.
B)   habitat structure.
C)   successional changes.
D)   ecological transitions.
E)   environmental gradient.

Question 6

When New York City needed to meet national water quality standards,they chose to invest $1.5 billion in protecting land and upgrading sewage systems in the Catskills (the source of their water)rather than spending $6-$8 billion on a new waste treatment facility in the city.This choice resulted in benefits in both New York City and the Catskills that included all of these except

Accepted Answer

A)   saving money.
B)   decreasing pollution.
C)   improving water filtration.
D)   improving sewage treatment.
E)   replacing a natural with a technological system.

Question 7

Which characteristic is not associated with high-intensity methods of coffee growing?

Accepted Answer

A)   Greater yield
B)   More pollution
C)   Increased biodiversity
D)   High cost of chemicals
E)   High-density plantations

Question 8

Which factor is not likely to be very important in determining species diversity?

Accepted Answer

A)   Habitat structure
B)   Climatic conditions
C)   Net primary productivity
D)   Occasional seasonal storms
E)   Large-scale disturbances,such as glaciation

Question 9

In the prairie community studies by Tilman and colleagues,two hypotheses were proposed to explain the increase in NPP as species richness increased.One involved accidental sampling,in which samples by chance included one or more "superspecies" that had a disproportionate effect on community function.Which other explanation did Tilman and his colleagues decide was more reasonable?

Accepted Answer

A)   Niche complementarity,leading to more efficient resource use
B)   Niche complementarity,leading to increased reproductive rates
C)   Changes in microclimate,leading to increased reproductive rates
D)   Decreased species evenness,leading to a few species influencing community function
E)   Increased species evenness,leading to all species equally influencing community function

Question 10

Which beetle(s)would most likely be found in recently deposited dung?

Accepted Answer

A)   Beetle A only
B)   Beetle B only
C)   Beetle C only
D)   Beetles A and B
E)   Beetles B and C

Question 11

Each species has a particular niche within a community.This niche is defined by which two sets of factors?

Accepted Answer

A)   Functional role and net primary productivity
B)   Physical environment and biological environment
C)   Net primary productivity and physical environment
D)   Net primary productivity and biological environment
E)   Physical and biological environment and functional role

Question 12

List as many ecosystem goods and services as you can think of that are active in your own life.Include goods and services that involve human intervention,as well as those that do not.

Accepted Answer

The answer of List as many ecosystem goods and services...

Question 13

The extinction of a predatory bird leads to an increase in the population of a small mammal,which in turn leads to a decrease in the population of the plants on which the mammal feeds.This series of changes is an example of a(n)_______.

Accepted Answer

The answer of The extinction of a predatory bird leads...

Question 14

Two communities each contain the same number of species.In one community,the major species are all present in approximately equal percentages.In the other,one species makes up more than 70 percent of the species,while all the others are divided among the remaining 30 percent.The two communities differ in their species _______.

Accepted Answer

The answer of Two communities each contain the same number...

Question 15

The introduction of a large predatory fish species into a lake will lead to declines in populations of smaller fish,which in turn cause an increase in plankton.This series of events is one example of

Accepted Answer

A)   succession.
B)   species turnover.
C)   a trophic cascade.
D)   a keystone exchange.
E)   an ecological transition.

Question 16

The value of ecosystem services depends greatly on an ecological factor that humans can maintain with careful management.This factor is

Accepted Answer

A)   species diversity.
B)   population density.
C)   climatic conditions.
D)   trophic interactions.
E)   species composition.

Question 17

When a species attempts to colonize a new area,all of these factors except _______ is likely to result in its local extinction.

Accepted Answer

A)   excessive predation
B)   excessive competition
C)   severe drought conditions
D)   lack of an essential resource
E)   a climate similar to its previous climate

Question 18

Refer to the diagram below.If both the scorpion and the roadrunner were eliminated from this food web,how would population sizes of other members of the web be affected?

Accepted Answer

The answer of Refer to the diagram below.If both the...

Question 19

Accumulated cattle dung in Australian pastures after the introduction of cattle caused pasture productivity to decline because

Accepted Answer

A)   nitrogen was not being recycled.
B)   it made the pastures too dry.
C)   it made the pastures too wet.
D)   too much free nitrogen was present.
E)   cattle refused to eat the grass,preventing more from growing.

Question 20

Habitat fragmentation leads to decreased species richness for all of these reasons except that

Accepted Answer

A)   the total amount of habitat decreases.
B)   the size of each habitat patch decreases.
C)   patches become more isolated from each other.
D)   patches become less isolated from each other.
E)   colonization rates decline because dispersal is limited.

Exam 44: Ecological Communities