Section

Name Date

Ecosystems
1.2
Summary
Textbook pages 34–51

Before You Read

How do you think ecosystems are related to the biomes you learned about in the
previous section? Record your ideas below.

◆
What is an ecosystem?
? Create a Quiz
In an ecosystem, abiotic components, such as oxygen, water,
Create a quiz to help you nutrients, light, and soil, support the life functions of biotic
learn the boldface terms components, such as plants, animals, and micro-organisms.
introduced in this section. Biomes contain many different ecosystems. Ecosystems can
Answer your questions and
share your quiz with your be small. Examples of small ecosystems include a tide pool
classmates. and a rotting log. Ecosystems also can be large. Examles of
large ecosystems include a coastal Douglas fir forest and a
biome.
Ecosystems contain different habitats. A habitat is the place
in which an organism lives. For example, a sculpin is a fish
that makes its habitat between rocks at the bottom of a tide
pool ecosystem. ● ✔

●
✔ Reading Check
What are the two main
How are biotic interactions in ecosystems
structured?
components of an Organisms within an ecosystem constantly interact to
ecosystem?
obtain resources, such as food, water, sunlight, or habitat.
As a result of these interactions, organisms have special
roles—or niches—in their ecosystems. An organism’s niche
includes the way in which it contributes to and fits into its
●
✔ Reading Check
Organize the following in
environment. Many different organisms can live in the same
habitat if they occupy different niches. Biotic interactions
the correct ecological hier- are structured from smallest to largest in an ecological
archy: community, ecosys- hierarchy.
tem, species, population.
◆ A species is a group of closely related organisms that can
reproduce with one another.
◆ All the members of a species within an ecosystem are
referred to as a population.
◆ Populations of different species that interact in a specific
ecosystem form a community. ● ✔

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 Section
Name Date
1. 2
Summary

continued

What different biotic interactions occur in

ecosystems?
Symbiosis refers to the interaction of two different organisms
that live in close association. Commensalism, mutualism,
and parasitism are types of symbiotic interactions. Other
biotic interactions include competition, predation, and
mimicry.

Interaction Result Example

commensalism One organism benefits and the other organism Barnacles attach to whales and are transported
is neither helped nor harmed. to new locations in the ocean.

mutualism Both organisms benefit and sometimes neither In lichen, the alga produces sugars and oxygen
species can survive without the other. for the fungus, which provides carbon dioxide
and water for the alga.
parasitism One species benefits and another is harmed. Hookworms attach to the gut wall and obtain
nourishment from their host’s blood.

competition Organisms require the same resource (such as Spotted knapweed releases chemicals into the
food) in the same location at the same time. soil, which prevents the growth of other plants.

predation One organism (the predator) eats all or part of Cougars have sharp, pointed teeth to catch prey.
another organism (the prey).

mimicry Prey animal mimics another species that is Viceroy butterflies look like bitter-tasting
dangerous or tastes bad to avoid being eaten. monarch butterflies and are avoided by
predators.

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 Name Date Comprehension
Section 1.2
Use with textbook pages 34–48.

Parts of an ecosystem
1. What is the difference between an ecosystem and a habitat?

2. List three main abiotic components of ecosystems.

3. What is the difference between a population and a community?

4. Define the term symbiosis.

5. What is commensalism?

6. How does mutualism differ from parasitism?

7. What is predation?

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 Interpreting
Name Date Illustrations
Section 1.2
Use with textbook pages 39–47.

Biotic interactions in ecosystems

Vocabulary
biosphere organism
community population
ecosystem

1. Use the vocabulary words in the box above to label the Williams Creek ecosystem.

II

IV
III

2. Give the ecological hierarchy for these biotic interactions from largest to smallest.

Largest

Smallest

3. List three populations that interact in your community.

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 Applying
Name Date Knowledge
Section 1.2
Use with textbook pages 39–47.

Symbiotic relationships
• commensalism • parasitism • predation
• mutualism • competition
Use the above terms to identify the following descriptions. Identify the term and
explain the relationship.
1. An ant lives in the thorns of the bullhorn acacia bush. The ant sips the nectar of the
acacia’s leaflets. The ants protect the plant by fighting off other insects.
Term:
Explanation:

2. Spotted knapweed releases chemicals into the soil. These chemicals prevent the
growth of other plants and allow the plant to spread quickly.
Term:
Explanation:

3. Lynx hunt snowshoe hares. When the lynx population increases the snowshoe hare
population decreases.
Term:
Explanation:

4. Spanish moss lives on trees in rainforests and has no roots. The feathery structure of
the Spanish moss captures nutrients and moisture from the air.
Term:
Explanation:

5. The mountain pine beetle is killing British Columbia’s lodgepole and white pine
forests.
Term:
Explanation:

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 Assessment
Name Date
Section 1.2

Use with textbook pages 34–48. Circle the letter of the best answer.
Ecosystems 8. What relationship is demonstrated by a
barnacle being attached to a whale?
Match each Term on the left with the best
A. mutualism
Descriptor on the right. Each Descriptor may be
used only once. B. commensalism
Term Descriptor C. parasitism
1. commensalism A. the special role an D. competition
2. competition organism plays in an
3. ecosystem ecosystem
9. Which of the following is an example of
4. mutualism B. a part of a biome in
mutualism?
5. niche which abiotic com- A. similar colouring of shrimp and crimson
6. parasitism ponents interact with anemone
7. predation biotic components
C. a symbiotic relationship B. hookworms attaching to a dog’s intestine
in which one species C. coyotes hunting in packs to kill large
benefits and another is animals
harmed
D. a symbiotic relationship
D. snapdragon flowers that open for bees of
in which one species a specific mass
benefits and the other 4000

Number of predators
Prey
species is neither 3000
Number of prey

Predator
2000 20
per km2

per km2
helped nor harmed 1000
500
E. a harmful interaction 300
100
10

between two or more 25

0 0
0 10 20 30 40
organisms that occurs Years
when the organisms
compete for the same 10. Which of the following situations best
resource in the same describes the relationship of the predator
location at the same and prey population shown in the graph
time above?
F. a symbiotic relationship
between two organisms A. As the predator population increases the
in which both organ- prey population increases.
isms benefit B. As the predator population decreases the
G. predator-prey interac- prey population decreases.
tions in which one
organism eats all or C. As the predator population increases the
part of another prey population decreases.
organism D. Predator population has no effect on prey
population.

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