Download 7.2 Extinction and Biodiversity Loss

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
Threatened
species
Habitat
fragmentation
Poaching
.
A species that has a high risk of
extinction
An endangered species is in danger
of going extinct.
Biodiversity at Risk
1. Is extinction a natural process? Explain.
2. Compare and contrast extinction with extirpation.
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.
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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
6. How do the effects of climate change differ from the effects of habitat alteration, invasive
species, overharvesting, and pollution?
7. What human activities lead to habitat loss?
8.
What is the greatest cause of biodiversity loss today?
9.
List two nonnative species—one that is invasive, and another that is not invasive.
10. Many protected animals are lost to poaching. What is a main motivation behind poaching?
11. 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.
12. What evidence suggests that we could be experiencing a sixth mass extinction?
12. What information is represented by the Living Planet Index?
13. List five causes of biodiversity loss.
14. What is the greatest cause of biodiversity loss today? Explain.