Name: 
 

Chapter 55



Multiple Choice
Identify the letter of the choice that best completes the statement or answers the question.
 

 1. 

Extinction is a natural phenomenon. It is estimated that 99% of all species that ever lived are now extinct. Why then do we say that we are now in a biodiversity crisis?
a.
Humans are ethically responsible for protecting endangered species.
b.
Scientists have finally identified most of the species on Earth and are thus able to quantify the number of species becoming extinct.
c.
The current rate of extinction is as much as 1,000 times higher than at any other time in the last 100,000 years.
d.
Humans have greater medical needs than at any other time in history, and many potential medicinal compounds are being lost as plant species become extinct.
e.
Most biodiversity hot spots have been destroyed by recent ecological disasters.
 

 2. 

According to the U.S. Endangered Species Act (ESA), the difference between an endangered species and a threatened one is that
a.
an endangered species is closer to extinction.
b.
a threatened species is closer to extinction.
c.
threatened species are endangered species outside the U.S. borders.
d.
endangered species are mainly tropical.
e.
There is no real difference.
 

 3. 

What is the term for a top predator that contributes to the maintenance of species diversity among its animal prey?
a.
keystone species
b.
keystone mutualist
c.
landscape species
d.
primary consumer
e.
tertiary consumer
 

 4. 

Which of the following most directly relates to the current biodiversity crisis?
a.
increased atmospheric carbon dioxide
b.
ozone depletion
c.
overexploitation of species
d.
habitat destruction
e.
zoned reserves
 

 5. 

Which of the following is not an example of an introduced species?
a.
brown tree snakes in Guam
b.
timber wolves in Minnesota
c.
zebra mussels in the Great Lakes
d.
kudzu plants in the southern United States
e.
starlings in New York
 

 6. 

Modern conservation science increasingly aims at
a.
protecting federally listed endangered species.
b.
lobbying for strict enforcement of the U.S. Endangered Species Act.
c.
sustaining biodiversity of entire ecosystems and communities.
d.
maintaining all genetic diversity within all species.
e.
both A and B
 

 7. 

Biodiversity hot spots are recognized on the basis of
a.
their proximity to national parks and reserves.
b.
the number of endemic species they contain
c.
the degree to which the included species are threatened with extinction.
d.
B and C only
e.
A, B, and C
 

 8. 

Human use of prokaryotic organisms to help detoxify a polluted wetland would be an example of
a.
ecosystem augmentation.
b.
keystone species introduction.
c.
biological control.
d.
bioremediation.
e.
population viability analysis.
 



 
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