Download Name Class Date 7.2 Extinction and Biodiversity Loss Key Concepts

Name
Class
Date
7.2 Extinction and Biodiversity Loss
Key Concepts
Scientists monitor biodiversity closely and have noticed significantly higher than
normal extinction rates in recent decades.
Habitat change and loss, invasive species, pollution, overharvesting, and climate change
are the major causes of biodiversity loss.
Vocabulary Preview
Define each vocabulary term in your own words. Then, write yourself a quick note on
how you will remember each. One term has been done for you.
Term
Definition
How I Remember
Extirpation
Endangered
species
A species that has a high risk of
extinction
Threatened
species
Habitat
fragmentation
Poaching
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An endangered species is in danger
of going extinct.
Name
Class
Date
Reading Strategy
Fill in the table to preview the lesson. Then, in the space that follows the table, write
one sentence to explain what you think this lesson will be about.
What is the title of this
lesson?
What are the vocabulary
terms for this lesson?
What are the key concepts
for the two main sections of
this lesson?
What do the photos
depict?
What do the diagrams
show?
EXTENSION Use the Internet to research threatened and endangered species in your
state. On a separate sheet of paper, name and describe at least one plant and one animal that is threatened or endangered.
Biodiversity at Risk
1. Is extinction a natural process? Explain.
2. Compare and contrast extinction with extirpation.
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Name
Class
Date
3. How does the background rate of extinction differ from mass extinctions?
4. Which type of species is more likely to become extinct, an endangered species or a
threatened species? Explain.
Causes of Biodiversity Loss
5.
Fill in the cause-and-effect diagram with a short description
that explains how each process leads to loss of biodiversity.
Habitat Alteration
Invasive Species
Biodiversity Loss
Overharvesting
Pollution
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Class
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6. How do the effects of climate change differ from the effects of habitat alteration, invasive
species, overharvesting, and pollution?
7. A conservation plan could proceed with a single 20-square kilometer habitat preserve or
with two habitat preserves, measuring a total of 20 square kilometers combined. Which
preserve format would support more species? Explain.
8. What human activities lead to habitat loss?
9. What are “habitat islands,” and how do they occur?
10.
How did studies of oceanic islands help scientists understand the effect of habitat
fragmentation on species diversity?
11.
What is the greatest cause of biodiversity loss today?
12.
What factors determine whether nonnative species are considered invasive?
13.
List two nonnative species—one that is invasive, and another that is not invasive.
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14. Many protected animals are lost to poaching. What is a main motivation behind poaching?
15. How do warming temperatures affect animals that live in cold climates?
Answer the questions to test your knowledge of lesson concepts. You can check your
work using the answers on the bottom of the page.
16. What evidence suggests that we could be experiencing a sixth mass extinction?
17. What information is represented by the Living Planet Index?
18. List five causes of biodiversity loss.
19. What is the greatest cause of biodiversity loss today? Explain.
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