MINDSTRETCHER
Study your homework
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Get out your homework and read it 2 times silently.
Get out a blank piece paper and put your heading
on it:
First & last name
Date
Class period
19-1 HW QUIZ
19-1 Homework Checkpoint
1. Nitrogen fixation
A. is done only by plants.
B. is done mostly by bacteria.
C. is how animals make proteins.
2. Burning gas in an automobile is a type of
A. Combustion
B. Respiration
C. Decomposition
3. Clouds form in the atmosphere through a process of
A. Precipitation
B. Respiration
C. Condensation
19-1 Homework Checkpoint
4. Which of the following statements about groundwater is
true?
A. It is stored in the spaces between or within rocks.
B . It is salty like ocean water.
C. It never reenters the water cycle.
5. The breakdown of dead material into carbon dioxide and
water is called
A. evaporation
B. condensation
C. decomposition
Carbon and Nitrogen Cycling
Carbon and Nitrogen Cycling Notes:
What is a carbon atom?
#6 on the periodic table. It’s symbol is “C”.
 Carbon is found in ALL living things.
 Carbon atoms continually move through
living organisms, the oceans, the
atmosphere, and the crust of the planet.
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Carbon Cycle Basics
Plants use carbon dioxide, water, and
sunlight to make sugar molecules and
oxygen. (Photosynthesis)
 Animals take in oxygen and break down
sugar molecules releasing energy, carbon
dioxide, and water. (Respiration)
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Simple picture…
Carbon Cycle Diagram
How do plants do it?
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Photosynthesis!
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The process by which producers use the energy
from sunlight to produce sugar, which
consumers convert to "fuel“.
6H2O + 6CO2 ----------> C6H12O6+ 6O2
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6 molecules of water + 6 molecules of carbon
dioxide = 1 molecule of sugar + 6 molecules of
oxygen
What happens when plants can’t
absorb all the carbon we produce?
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Carbon builds up in our atmosphere and oceans.
Adding too much carbon too quickly causes Global
Warming.
Key Terms/Ideas for the Carbon Cycle:
Combustion- burning of fossil fuels adds more
carbon to the atmosphere
Decomposition- animals die and decompose,
returning molecules to the soil.
*Animals get carbon by eating other organisms.
Carbon Cycle Summary
Summarize the Carbon Cycle.
 Name two things you can do to lower the
amount of Carbon in the atmosphere.
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Where is nitrogen?
Take a deep breath. You just
breathed in a whole bunch of
nitrogen!
78% of earth’s atmosphere
consists of Nitrogen.
(Trivia-3% of Mars atmosphere
is nitrogen.)
Since nitrogen is so important
you’d think this was a good
thing, right?
Is Nitrogen Important?
Nitrogen is in
chlorophyll
molecules
which is
necessary for
photosynthesis.
Is Nitrogen Important?
All life requires nitrogen. (protein and DNA
are just a few uses)
 Air is 78% nitrogen gas (N2).
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Nitrogen Cycling Basics
Most organisms cannot use nitrogen in the
form N2 or “Free Nitrogen”.
 It must be combined with other molecules or
“Fixed”.
 This is done by bacteria who live in “nodules”
on plant roots. (example of mutualism)
 Lightning also fixes Nitrogen.
 Decomposition- adds Nitrogen to soil
 Animals get nitrogen by eating the plants!
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Other Ways to Fix nitrogen
Lightning can fix nitrogen with
its incredible concentration of
energy. This amounts to a small
amount of lightning fixation.
The lightning breaks the bond
and the nitrogen combines with
oxygen to create NO3. (a form
plants can use)… which is then
washed into the soil by rain.
Let’s put it all together!
Nitrogen in Action
Simple Picture
Additional Nitrogen Cycle Examples:
Remember……
Water, Carbon, and Nitrogen are all
necessary to living things.
 All three are types of matter.
 All three are constantly being cycled through
producers, consumers, decomposers, and
the environment.
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