The Cycling of Matter Name _________________________
Earth is a system that relies on the constant input of energy from the sun and on the cycling of matter.
Refer to the diagrams of the carbon cycle & the nitrogen cycle, and the population density information in your Unit 5 notes to help you complete this activity. You may also want to refer to the information on photosynthesis and cellular respiration in your Unit 3 notes.
Question #1
Plants and animals impact the cycling of carbon into and out of the atmosphere. a) Imagine that you are an atom of carbon. Describe how you might cycle through the biosphere starting as a CO2 molecule in the atmosphere. You must go through at least 4 different transformations before being returned to the atmosphere.
In your description, be sure to:
 Describe the path of the carbon atom, being sure to include the atmosphere, plants and animals
 Identify the molecule that contains the carbon in each step of the path
You may use words, chemical formulas, and/or labeled diagrams in your answer. b) Imagine that an entire forest is wiped out by a large fire. How would this affect the cycling of carbon?

c) How has this fire affected the population of other organisms in the forest ecosystem?
In your description be sure to:
 Identify an organism in the forest ecosystem
 Describe how the population of that organism could be limited by the removal of trees
Question #2
Todd and Ana own a house on 10 acres of land south of Kennewick. One of the things they enjoy watching are the rabbits that feed on the shrubs and grasses surrounding their home. a) Describe the cycle of carbon through this outdoor ecosystem
In your description be sure to:
 Describe how carbon became a part of the shrubs and grasses
 Describe how that carbon will become part of the rabbit’s tissues when it eats the plants
Carbon in plants:

Another way:
Carbon in rabbits: b) Describe two ways the carbon could be released from the rabbit back into the ecosystem.
One way:

Question #3
Photosynthesis and Cell Respiration are two important processes for life. a) Write the equation for photosynthesis in the box. Label the inputs and outputs. Explain which parts are matter and which parts are energy. b) Write the equation for cell respiration in the box. Label the inputs and outputs. Explain which parts are matter and which parts are energy.