Question 1

Divisions of organisms in a community, based on the way in which they obtain their energy, is/are called

Accepted Answer

A)  a food chain. 
B)  trophic levels. 
C)  food webs. 
D)  pyramids. 
E)  consumers.

Question 2

Which of the following statements regarding species diversity is false?

Accepted Answer

A)  If two communities have the same species richness, the one with the more even distribution of species is considered more diverse. 
B)  Beta diversity is a measure of the change in species composition from one community or habitat to another. 
C)  For many taxa, species diversity decreases with distance from the equator. 
D)  Gamma diversity is the regional diversity found over a range of communities or habitats in a geographic region. 
E)  Sorenson's index is used to estimate the alpha diversity of a community.

Question 3

Which of the following statements about species richness is true?

Accepted Answer

A)  It is highest in the temperate zone in 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)  None of the above

Question 4

The introduction of a large predatory fish into a lake will lead to declines in the populations of smaller fish; this decrease in the smaller fish will lead to an increase in the plankton on which they feed. This phenomenon is called

Accepted Answer

A)  character displacement. 
B)  keystone exchange. 
C)  trophic cascade. 
D)  primary succession. 
E)  heterotrophic succession.

Question 5

Which of the following places stages of ecological succession occurring on glacial moraines in Alaska in correct chronological sequence, from earliest to latest?

Accepted Answer

A)  Increase in soil nitrogen; arrival of lichens; arrival of willows and alders; arrival of conifers; arrival of bacteria, fungi, and photosynthetic microorganisms 
B)  Increase in soil nitrogen; arrival of bacteria, fungi, and photosynthetic microorganisms; arrival of lichens; arrival of willows and alders; arrival of conifers 
C)  Arrival of bacteria, fungi, and photosynthetic microorganisms; increase in soil nitrogen; arrival of lichens; arrival of willows and alders; arrival of conifers 
D)  Arrival of bacteria, fungi, and photosynthetic microorganisms; arrival of lichens; arrival of willows and alders; increase in soil nitrogen; arrival of conifers 
E)  Arrival of bacteria, fungi, and photosynthetic microorganisms; arrival of conifers; arrival of willows and alders; arrival of lichens; increase in soil nitrogen

Question 6

Most species of spiders eat plant-eating insects. Spiders are thus primary _______, or secondary _______.

Accepted Answer

The answer of Most species of spiders eat plant-eating insects....

Question 7

Which of the following represents primary succession?

Accepted Answer

A)  The development of an aquatic community in a newly excavated farm pond, eventually followed by the filling in of the pond with sediment and its conversion to a forest 
B)  The development of a terrestrial community on lava produced by a volcanic eruption 
C)  The gradual establishment of a forest following a fire that destroyed the previous community 
D)  The invasion of weeds followed by shrubs and trees on an abandoned farm field 
E)  Both a and b

Question 8

Earthworms feed off of dead material and are thus considered _______.

Accepted Answer

The answer of Earthworms feed off of dead material and...

Question 9

Which of the following statements about disturbances is false?

Accepted Answer

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)  All of the above are true; none is false.

Question 10

In calculating alpha diversity, the Shannon diversity index measures

Accepted Answer

A)  the absolute abundance of species. 
B)  the relative abundance of species. 
C)  the ecological diversity of species. 
D)  the morphological diversity of species. 
E)  differences in species composition across habitats or communities.

Question 11

Species whose influences on ecosystems are greater than would be expected, based on their abundance, are called

Accepted Answer

A)  primary producers. 
B)  secondary consumers. 
C)  flagged species. 
D)  keystone species. 
E)  disturbance specialists.

Question 12

Which of the following factors reduces the efficiency of energy transfer between trophic levels?

Accepted Answer

A)  Lack of availability of some biomass 
B)  Heat loss 
C)  Indigestibility of some biomass 
D)  All of the above 
E)  None of the above

Question 13

Which of the following always has a "pyramidal" shape (i.e., decreasing values at higher trophic levels)?

Accepted Answer

A)  Pyramids of number 
B)  Pyramids of biomass 
C)  Pyramids of energy 
D)  Both a and b 
E)  None of the above

Exam 57: Community Ecology