Unit 5: Carbon, Photosynthesis & Respiration


Unit 5 focuses on the carbon cycle, with emphasis on the exchange of carbon dioxide (CO2) within plants. Students will grow plants and monitor CO2 production and consumption. The goals of this unit are for students to be able to explain that growth is the result of plant net uptake of carbon dioxide, and that carbon dioxide production exceeds the levels plants can convert to oxygen. Lab activities will also help students see the potential impacts of carbon dioxide fertilization.

Unit Placement in the Course: 

This unit is designed to be taught as part of a sequence with a unit on the nitrogen cycle (Unit 6). While each unit can stand alone, together they provide essential knowledge needed to understand the complex science underlying climate change. 

Required Supplies: 

CO2 Fertilization of Wheat: (5 weeks of growth time required) 

  • 2 1-gallon Containers (recommended: Rubbermaid 6 qt. clear square food storage container-FG630600CLR) with lids 
  • 2 milk jugs
  • Small container (+/- 8 oz.)
  • Wheat seeds (recommend soaking overnight)
  • Alka-Seltzer tablets
    • CO2 Sensor
    • O2 Sensor

Photosynthesis vs. Respiration & CO2 Levels (Plants will need to be about 2 inches tall to get better results, lab works great as a follow up to the CO2 fertilization lab, using the plants grown in that experiment.) 

  • CO2 Sensor
  • 2 1-gallon Chambers
  • Temperature probe
  • Vernier interface cable, CBL, or LabQuest
  • Vernier Logger Lite
  • Wheat Seeds (berries)
  • Empty milk cartons

Note: Supplies listed have been field tested, similar products may be used.

Full Supply List...


Materials Provided: 

  • PowerPoint Presentation
  • Teacher notes on most slides to help guide class discussion
  • Two classroom lab activities
  • Classroom readings on carbon storage capabilities of soil and biomass

Estimated Teaching Time: 

  • Five 50-minute class periods.