Name: Section: Number:

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Vocabulary

Word Definition

competition

p.114

parasite

p.117

host

p.117

succession

p.118

extinct

p.120

endangered

p.120

hazardous waste

p.126

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Lesson 1: How are ecosystems balanced? page 110-113

1. Interactions among living and nonliving things help maintain ______________

in ecosystems.

2. What do all plants and animals need to live and grow?

3. How does a forest meet the needs of a chipmunk?

4. How could a forest fire affect the balance of a forest ecosystem?

5. What keeps the balance in an ecosystem?

6. What happens when the number of organisms in a population increases?

7. If one of the populations in a community doubled, what would be likely to

happen to that community?

8. What is something that might prevent a plant population from growing in

size?

9. In what ways is balancing an ecosystem like balancing a seesaw?

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Lesson 2: How do organisms interact? page 114-117

1. When species compete for a particular resource, what happens to the

losers?

2. Populations grow when _________________________

3. What happens when two or more species must use the same limited

resources?

4. How can wolves successfully hunt deer that are in a group?

5. What are two behaviors that help animals avoid or reduce competition?

6. When two organisms live closely together, the relationship can be

7. These special relationships exist between

8. Describe the relationship between algae and fungi.

9. In a relationship when one organism is helped and one is harmed, the

helped is called______________, and the harmed is called _________________.

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10. Describe the relationship between the insect, balsam woolly adelgid, and

Fraser fir tree.

11. What might happen to the parasite if its host were to die?

Label the organisms are a host or a parasite in the relationship

below: Tapeworms are flatworms

that attach themselves to

the intestines of animals such

as cows, pigs, and humans.

They get food by eating the

host's partly digested food,

depriving the host of

nutrients.

tapeworrm animal

Fleas land on animals, such

as dogs, and bite their skin,

sucking their blood, and

causing them to itch. The

fleas, in turn, get food and a

warm home.

flea dog

A tick is a small insect that

lands on an animal, such as

a deer, out in the woods.

The tick feeds on the animal.

The animal that it lands on

may develop Lyme disease

as a result.

deer tick

Head lice infest a creature’s

hair and suck blood from the

scalp. This damages the

creatures’s scalp and leads

to small blood loss and

itching, while providing a

habitat for the head lice.

creature lice

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Lesson 3: How do environments change? page 118-123

1. The process of gradual change from one community or organisms to

another is called_____________________.

2. When does succession occur?

3. How does a warming climate affect an environment?

4. Using the illustration on page 118-119 describe how a forest could have once

been a lake.

5. If an animal is extinct ___________________________________________________.

6. Why might an animal become extinct?

7. When are species considered threatened?

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8. When a species becomes extinct, what are some effects on the ecosystem

to which in belonged?

9. What can we learn about the environment from studying fossils?

10. What are some events that change an environment very quickly?

11. What are two processes that change an environment slowly over a very

long period of time?

12. How could a forest fire help to keep that forest ecosystem balanced?

13. If there is a flood, the population of which organisms might increase? Why?

13. What can a major flood do to an existing community?

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Lesson 4: How do people disturb the balance? page 124-129

1. Why do humans have a great impact on the environment?

2. List some specific ways that humans change the ecosystem to get what

they need.

3. What are some ways in which humans pollute the air?

4. What effects can pollutants have on other organisms?

5. List one way the water pollution affects the organisms that live there.

6. How do you think humans could return some balance to

ecosystems?

6. What is a hazardous waste?

7. What effect could leaking hazardous waste containers have on the

ecosystem?

8. If a company is planning to use land for mining, what plan must they have

beforehand?

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9. How has preservation of national parks helped the environment?

10. Name some natural environments in the United States that have been set

aside for preservation as national parks.

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1. An organism that feeds on and harms a

living thing is called a(n)

____________________.

2. A species that is _________________ has no

living members.

3. ________________ is the struggle between

organisms to meet their needs.

4. A species that is at risk of dying out is a(n)

____________________ species.

5. ________________can be very harmful to organisms and the environment.

6.The process of one community gradually replacing another community is

________________________.

7. A(n) ________________ is an organism that provides energy or an environment

for another organism.

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1. Animals survive where their _______________________________.

2. Grass makes _______________ and animals use it to help them breathe.

3. If a habitat is destroyed, animals may become ______________.

4. Animals that eat other animals help keep the ecosystem _________________.

5. A parasite hurts the ___________, but helps itself.

6. One community gradually replacing another is called ________________.

7. If the number of animals that get eaten decreases, the number of predators

would _________________.

8. In order to preserve nature’s habitats, the US established _________________.

1. Describe a balanced ecosystem.

2. List natural disasters that could change an ecosystem quickly.

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3. Describe how a change in climate could affect that ecosystem.

4. If a fish fossil was found in the desert, what could you assume about that

ecosystem?

5. If a meadow had too many rabbits, what would help balance that

ecosystem?

6. How do people disturb the balance of the ecosystem?