What the tree breathes out, you breathe in. Seal a tree and a person inside a glass chamber, dim the lamp, make the person exercise, and watch the oxygen and carbon dioxide trade places. Then zoom into the cells to see the chloroplast build the sugar that the mitochondria burn.
Chamber Air
Fresh and balanced
Oxygen (O₂)22%
Carbon Dioxide (CO₂)Low
Kitchen-Table Insight
Balanced trade
The tree uses the person's breathed-out carbon dioxide. In return it supplies the oxygen and the sugar the person needs.
Photosynthesis vs. Cellular Respiration: a guide for parents
Grade 7 • Science • Free, no login
Seal a tree and a person in a glass chamber and watch them trade oxygen and carbon dioxide.
Kitchen Table Prompt
Turn the lamp off and ask why the oxygen starts falling even though the tree is still there. Plants breathe too. In the light they make more oxygen than they use, and in the dark they only use it.
Standards this lesson covers
National / 44+ States (NGSS): MS-LS1-6 & MS-LS2-3 (Carbon Cycling, Photosynthesis & Cellular Respiration)
Texas (TEKS): TEKS 7.5B / 8.11A (Photosynthesis, Radiant to Chemical Energy & Gas Exchange)
Florida (NGSSS): FL NGSSS SC.8.L.18.1 & SC.8.L.18.2 (Matter & Energy in Photosynthesis & Respiration)
Virginia (SOL): VA SOL LS.4.b & LS.5.c (Photosynthesis, Cellular Respiration & Carbon Balance)
North Carolina (SCOS): NC SCOS 8.L.5.1 (Food Energy, Cellular Respiration & Gas Cycling)
