Document 276980

SCIENCE &
AND
GLOBAL
GLOBAL
ISSUES/BIOLOGY ISSUES/BIOLOGY • ECOLOGY
• ECOLOGY
DOING THE ACTIVITY
2 Students should complete the
carbon cycle simulation on the
­Science and Global Issues page of
the SEPUP website (sepuplhs.org/sgi).
All directions for this s­ imulation
are on Student Sheet 8.1, “Carbon
Cycle,” which can be downloaded
from the same website.
SCIENCE & GLOBAL ISSUES/BIOLOGY • ECOLOGY
Procedure
1. With your partner, visit the Science and Global Issues page of the SEPUP
website at sepuplhs.org/sgi and go to the carbon cycle simulation. Use your
student sheet to guide you through the simulation.
2
3 Analysis
1. What happens to the total amount of carbon as it moves through the
carbon cycle?
2. In what ways does human activity affect the carbon cycle? Support your
answer with evidence.
3. Explain one possible path a carbon molecule might take if it began in
a small fish and ended up in a blade of grass.
FOLLOW-UP
3 (UC ASSESSMENT) Discuss with
the class how the pre- and post-­
industrial carbon cycles differ. See
the S­ cience and Global Issues website
(sepuplhs.org/sgi) for more information on how to hold this class discussion. Analysis Question 3 is
an opportunity for you to use the
UNDERSTANDING CONCEPTS (UC)
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Scoring Guide to assess students’
understanding of the carbon cycle.
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EXTENSION
Slide presentations on other biochemical cycles are available on the Science
and Global Issues page of the SEPUP
website (sepuplhs.org/sgi).
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This diagram of the carbon cycle shows how carbon is exchanged between carbon reservoirs
by processes that involve geological changes and organism interactions.
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SAMPLE RESPONSES
1. The total amount of carbon atoms in the system stays the
same even though carbon moves from reservoir to
reservoir.
3.
2. The carbon cycle shows how the carbon moves between
carbon reservoirs on earth and in the earth’s atmosphere.
Humans can affect a part of the carbon cycle by doing
such things as cutting down a forest. When the forest is
removed, the trees will no longer remove carbon from
the atmosphere. This means that more carbon dioxide
may build up in the atmosphere reservoir if it is not
removed in some other way. Thus, humans can create
imbalances in the natural cycle of carbon on Earth.
Sample Level-3 Response
Carbon is a part of molecules in the body of a fish. The
fish respires and releases carbon dioxide into the water.
The carbon dioxide is transferred from the water into
the atmosphere. The grass takes in the carbon dioxide
from the atmosphere and uses it during photosynthesis
to create carbon-containing molecules. These carbon­containing molecules from photosynthesis are incor­
porated into the blade of grass.
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A correct and complete answer would
explain that the carbon would pass through reservoirs in
the carbon cycle, eventually traveling from the small fish
to a blade of grass. Students’ answers will vary.
(UC ASSESSMENT)