EarthLabs Assessment: Lab 1
Examples of Important Molecules in the Carbon Cycle
1. Which element forms the structural backbone of the molecules in the image
above?
a. Oxygen
b. Hydrogen
c. Methane
d. Carbon
2. Scientists believe that more than ten million different types of carbon compounds
exist here are Earth. Which of the following explains why carbon compounds can
exist in so many different shapes and sizes? Circle ALL that apply.
a. Carbon forms three bonds
b. Carbon can bond easily with other carbon atoms
c. Carbon can bond in four directions
d. Carbon can bond with other carbon atoms to make branches and chains
e. The bonds between carbon, hydrogen and oxygen atoms can break and the
atoms can bond together into new shapes.
3. A tree grows by biosynthesizing(creating) new carbon compounds in its cells and
tissues. The source of the carbon in these new carbon compounds is originally from
a. soil
b. water
c. air
d. animals
4. Which of the following carbon cycle processes produces carbon dioxide (CO2)
which then goes into the air. Circle ALL that apply.
a. Photosynthesis
b. Respiration
c. Combustion
d. Decomposition
e. Biosynthesis
5. Constructed Response:
Choose one of the carbon cycle processes below. Explain how this carbon cycle
processe changes carbon compounds from one form into another.
Carbon Cycle Processes:
 Photosynthesis
 Respiration
 Combustion
 Decomposition
 Biosynthesis