AP ENVIRONMENTAL SCIENCE
STUDY GUIDE – CHAPTER 9: Sustaining Biodiversity – The Species Approach
Key Questions and Concepts
1. What role do humans play in the extinction of species? (9-1)
2. Why should we care about the rising rate of species extinction? (9-2)
3. How do humans accelerate species extinction? (9-3)
4. How can we protect wild species from extinction? (9-4)
Review Questions
1. Review the Key Questions and Concepts for this chapter on page 191. Describe how human activities threaten polar bears in
the arctic.
2. What is biological extinction? Define background extinction rate and mass extinction. How is an extinction rate expressed?
What was the background extinction rate (as a percentage)? How can the extinction of a species affect other species and
ecosystem services? Describe how scientists estimate extinction rates. Give three reasons why many extinction experts
believe that human activities are now causing a sixth mass extinction. Distinguish between endangered species and
threatened species and give an example of each. List four characteristics that make some species especially vulnerable to
extinction. Describe the extinction of the passenger pigeon in North America.
3. What are three reasons for trying to avoid causing the premature extinction of wild species? Describe two economic and two
ecological benefits of having the current variety of species.
4. What are four underlying causes of species extinction that results from human activities? What is HIPPCO? In order, what
are the six largest causes of premature extinction of species resulting from human activities? What is habitat fragmentation?
Describe the major effects of habitat loss and fragmentation. Why are island species especially vulnerable to extinction?
5. Give two examples of the benefits of introducing some nonnative species. Give two examples of the harmful effects of
nonnative species that have been introduced (a) deliberately and (b) accidentally. Describe the harmful and beneficial effects
of kuduz. List four ways to limit the harmful impacts of nonnative species. Describe the roles and population growth,
overconsumption, pollution, and climate change in the extinction of wild species. Explain how pesticides such as DDT can be
biomagnified in food chains and webs. Describe the decline of some honeybee populations in the U.S. and list possible
causes of the problem. What is colony collapse disorder and what might be causing it? What economic and ecological roles
do honeybees play?
6. Describe the poaching of wild species and give three examples of species that are threatened by this illegal activity. Why are
tigers likely to disappear within a few decades? Describe how Pilai Poonsward helped to protect rare rhinoceros hornbills in
Thailand. Describe the threat to some forms of wildlife form increased hunting for bush meat.
7. Describe the major threats to bird species in the world and in the United States. List three reasons why we should be alarmed
by the decline of bird species. Describe the relationship between cultures, wild hogs, and rabies in India.
8. Describe two international treaties tat are used to help protect species. Summarize the history of the U.S. Endangered Species
Act. How successful it has been, and why is it controversial?
9. Describe the roles and limitations of wildlife refuges, gene banks, botanical gardens, wildlife farms, zoos, and aquariums in
protecting some species. Describe efforts to protect the California condor from extinction. What is the precautionary principle
and how can we use it to help protect wild species and overall biodiversity? What are three important issues related to the use
of this principle?
10. What are this chapter’s three big ideas? Describe how the three principles of sustainability related to protecting the polar bear
and other wild species from extinction and protecting the earth’s overall biodiversity.
Critical Thinking
1. What are three aspects of your lifestyle that might directly or indirectly contribute to the endangerment of the polar bear?
2. Describe your gut-level reaction to the following statement: “Eventually, all species become extinct. So it does not really
matter that the passenger pigeon is extinct or that the polar ear or the world’s remaining tiger species are endangered mostly
because of human activities”. Be honest about your reaction and give arguments to support your position.
3. Do you accept the ethical position that each species has the inherent right to survive without human interference, regardless
of whether it serves any useful purpose for humans? Explain. Would you extend this right to the Anopheles mosquito, which
transmit malaria to infectious bacteria, and to individual tigers that have killed people? Explain.
4. Wild life ecologist and environmental philosopher Aldo Leopold wrote this with respect to preventing extinction of wild
species: “To keep ever cog and wheel is the first precaution of intelligent tinkering”. Explain how this statement related to the
material in this chapter.
5. What would you do if fire ant invaded your yard and house? Explain your reasoning behind your course of action. How
might your reasoning affect other species or the ecosystem you are dealing with?