Question

Objective 3

Describe how photosynthesis and cellular respiration contribute to the
exchange of carbon between the biosphere, atmosphere, hydrosphere, and
geosphere.
1. What are
Earth's four main
spheres?
Use the image
to the right.
2. During cellular
respiration, where
does the carbon
go?
3. During
photosynthesis,
where does the
carbon go?
4. When fossil
fuels are burned
(combustion),
where does the
the carbon go?
1. Lithosphere -
1234
2.
3.
Atmosphere
Hydrosphere -
4. Biosphere -
Lithosphere - solid earth
Hydrosphere - all water
Combustion
gives off CO₂
Animals eat plants,
which contain carbon
#
CO₂
Atmosphere - gases (the air)
Biosphere - all life
Green plants absorb CO₂
Animals respire
and gives off CO₂
Sanda
Decomposing matter
gives off CO.

Answer 1

1. The four main spheres of the Earth are the lithosphere (solid earth), hydrosphere (all water), atmosphere (gases or the air), and biosphere (all life).
2. During cellular respiration, the carbon is released as carbon dioxide (CO₂) and is exhaled by the organism into the atmosphere.
3. During photosynthesis, the carbon is absorbed from the atmosphere in the form of CO₂ and is converted into organic molecules (such as glucose) that are used by the plant for energy and growth.
4. When fossil fuels are burned (combusted), the carbon that was stored in the fuels is released into the atmosphere as carbon dioxide (CO₂), contributing to the increase in atmospheric CO₂ levels.

In summary, photosynthesis and cellular respiration are part of the carbon cycle, which involves the exchange of carbon between the atmosphere, biosphere, hydrosphere, and lithosphere. During photosynthesis, carbon is absorbed from the atmosphere and converted into organic molecules, while during cellular respiration, carbon is released back into the atmosphere as CO₂. When fossil fuels are burned, the carbon stored in them is released into the atmosphere as CO₂. This exchange of carbon between the different spheres helps to maintain the balance of carbon in the Earth's systems.