Download Biodiversity (pages 95–105)

Name
Date
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■
Class
Adapted Reading and Study
Biodiversity
(pages 95–105)
The Value of Biodiversity
(pages 96–97)
Key Concept: Biodiversity has both economic value
and ecological value within an ecosystem.
• The biodiversity of an area is the number of different
species that live there. Protecting biodiversity is
important for two main reasons: biodiversity has money
value, and biodiversity is important for the health of
ecosystems.
• Many plants, animals, and other living things have
economic value. Having economic value means having
worth in terms of money. For example, some plants and
animals supply materials used to make clothes.
• All species have ecological value. Having ecological
value means affecting the other living things in an
ecosystem. For example, species depend on each other
for food and shelter.
• A keystone species is a species that affects whether or
not other species in an ecosystem keep living or die off.
Answer the following questions. Use your textbook and the
ideas above.
1. Read each word in the box. In each sentence below, fill
in the correct word or words.
biodiversity
keystone species
economic value
a. A
is a species that affects
whether or not other species in an ecosystem keep
living or die off.
b. The
of an area is the
number of different species that live in the area.
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Name
Date
Living Resources
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Class
Adapted Reading and Study
2. Circle the letter of each sentence that is true about
biodiversity.
a. Biodiversity has no value to humans.
b. Biodiversity has ecological value.
c. Biodiversity has economic value.
Factors Affecting Biodiversity
(pages 98–99)
Key Concept: Factors that affect biodiversity in an
ecosystem include area, climate, and diversity of
niches.
• Biodiversity varies from place to place.
• An area’s biodiversity can depend on its size. A larger
area usually has greater biodiversity than a smaller
area.
• An area’s biodiversity can depend on its climate.
Tropical rain forests, for instance, have great
biodiversity.
• An area’s biodiversity can depend on its niche diversity.
Niche diversity is how many different ways organisms
can live in an ecosystem. For example, a coral reef has
great biodiversity because organisms can live under, on,
and among the coral.
Answer the following questions. Use your textbook and the
ideas above.
3. Circle the letter of each sentence that is true about
factors affecting biodiversity.
a. Climate does not affect an area’s biodiversity.
b. Tropical rain forests and coral reefs both have great
biodiversity.
c. A larger area usually has a greater biodiversity than
a smaller area.
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Name
Date
Living Resources
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Class
Adapted Reading and Study
4. Complete the concept map about factors that affect
biodiversity.
Biodiversity
is affected by
Niche
diversity
a.
b.
Gene Pool Diversity
(page 99)
Key Concept: The organisms in a healthy population
have a diversity of traits.
• A trait is a characteristic of an organism. For example,
traits include the color of an organism and the size of an
organism.
• Genes determine an organism’s traits. Genes are the
structures in cells that carry information about the traits
passed from parents to their offspring.
• Each organism has some genes that others in the same
species do not have. The total number of genes found in
a species is called its gene pool.
• A species with a lot of different genes in its gene pool
has a diversity of traits—many different traits. A diversity
of traits is also called gene pool diversity. Having gene
pool diversity makes it easier for the species to adapt to
changes in the environment.
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51
Name
Date
Living Resources
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Class
Adapted Reading and Study
Answer the following questions. Use your textbook and the
ideas on page 51.
5. The structures in cells that carry information about
traits passed from parents to their offspring are called
.
6. Is the following sentence true or false? Traits determine
an organism’s genes.
7. Circle the letter of the sentence that explains why
having gene pool diversity is good for a species.
a. The species can more easily adapt to changes in
the environment.
b. The species finds it hard to adapt to changes in the
environment.
c. The species can never adapt to changes in the
environment.
Extinction of Species
(pages 100–101)
Key Concept: Extinction is a natural process. But in
the last few centuries, the number of species
becoming extinct has increased dramatically.
• Extinction is when all members of a species disappear
from Earth. Species can become extinct naturally.
People can also cause species to become extinct.
• An endangered species is a species that is in danger
of becoming extinct soon.
• A threatened species is a species that could become
an endangered species soon.
• Making sure that species do not become extinct is one
way to protect Earth’s biodiversity.
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Name
Date
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Class
Adapted Reading and Study
Answer the following question. Use your textbook and the
ideas on page 52.
8. Complete the table about terms related to the
extinction of species.
Extinction of Species
Term
Meaning
a.
The disappearance from Earth
of all members of a species
b.
A species that is in danger
of becoming extinct soon
c.
A species that could become
an endangered species soon
Causes of Extinction
(pages 102–103)
Key Concept: Human activities can threaten
biodiversity. These activities include habitat
destruction, poaching, pollution, and the introduction
of exotic species.
• The major cause of extinction is habitat destruction.
Habitat destruction is when a natural habitat is
destroyed. For example, cutting down a forest to build a
town is habitat destruction.
• Habitat fragmentation is when a habitat is broken up
into small areas. Building a road through a forest is an
example of habitat fragmentation.
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Adapted Reading and Study
• Poaching is the illegal killing or capture of animals in
the wild. Hunters kill some animals for their parts, such
as their fur or horns.
• When humans carry a new species into an area, that
exotic species can cause extinction of species already
living there.
Answer the following questions. Use your textbook and the
ideas on page 53 and above.
9. Draw a line from each term to its meaning.
Term
Meaning
habitat destruction
habitat fragmentation
a. the illegal killing or
capture of animals in
the wild
poaching
b. when a natural habitat
is destroyed
c. when a habitat is broken
up into small areas
10. Look at the picture below. What human activity does
the picture show?
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Name
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Class
Adapted Reading and Study
Protecting Biodiversity
(pages 104–105)
Key Concept: Three successful approaches to
protecting biodiversity are captive breeding, laws and
treaties, and habitat preservation.
• Captive breeding is having animals in zoos or wildlife
preserves mate and reproduce.
• Laws and treaties can protect species. A law in the
United States called the Endangered Species Act
protects threatened species and endangered species.
International treaties can protect species around the
world by outlawing the buying and selling of endangered
species.
• Protecting a whole ecosystem is the best way to protect
biodiversity. Protecting a whole ecosystem protects
endangered species living there. It also protects any
species that depends on the endangered species.
Answer the following questions. Use your textbook and the
ideas above.
11. Having animals in zoos or wildlife preserves mate and
reproduce is called
breeding.
12. Circle the letter of what the Endangered Species Act
protects.
a. captive breeding in zoos
b. threatened species and endangered species
c. animals in other countries
13. Is the following sentence true or false? Protecting a
whole ecosystem is the best way to protect
biodiversity.
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