Name _______________________________________________________ Class ________ Date _______________________________________________
The Carbon-Oxygen Cycle
Background: Carbon and oxygen are constantly being recycled in ecosystems. They can be found as compounds in living things, in the atmosphere as a
gas, and in the soil as other compounds. These processes are linked and all producers and consumers play an important part in allowing the cycles to continue.
Directions: Fill in the table below. Each box should explain how a transition can occur from one location to another.
Organisms  Atmosphere
Atmosphere  Organisms
Organisms  Soil
Through respiration
Through respiration
heterotrophs breathe heterotrophs take in
out CO2
O2
When organisms die
the carbon
compounds get
returned into the soil
Through
Through
photosynthesis
photosynthesis
autotrophs take in
autotrophs release O2 CO2
When organisms
produce waste carbon
molecules are
returned into the soil
Air mixes with water
When organisms burn and transfers CO2 and
they release carbon
O2 to aquatic plants
into the atmosphere and animals
Soil  Organisms
Plants take up
nutrients in their
roots that can include
carbon compounds
1. What do producers release when they conduct photosynthesis? Oxygen
2. What happens to the oxygen released into the atmosphere? It
gets taken in by heterotrophs
3. Where do producers get the carbon dioxide they need? From
the atmosphere
4. What would prevent this cycle from continuing on indefinitely? If
there were no plants, CO2 would not be taken
out of the atmosphere and O2 would not be provided to the hetertrophs
5. In what ways can humans impact the exchange of carbon and oxygen in the atmosphere?
List two. 1.
Burning more fuel
(releases more carbon into the atmosphere) 2. Cutting down trees decreases the amount
of O2 being placed in the atmosphere
6. Explain how you think a cow eating grass is part of the carbon and oxygen cycles.
Cow breathes in O2, breathes out CO2. Cow eats carbon compounds in the grass, then
returns carbon compounds back into the soil through waste products