Energy Transfers

Question 1

The concentrations of carbon dioxide in the air at different heights above ground in a forest changes over a period of 24 hours. Use your knowledge of photosynthesis to describe these changes and explain why they occur (6)

Answer 1

1. High concentration of carbon dioxide linked with night/darkness;
2. No photosynthesis in dark/night / light required for photosynthesis/light-dependent reaction;
3. (In dark) plants (and other organisms) respire;
4. In light net uptake of carbon dioxide by plants/plants use more carbon dioxide than they produce/ rate of photosynthesis greater than rate of respiration;
5. Decrease in carbon dioxide concentration with height;
6. At ground level fewer leaves/less photosynthesising tissue/more animals/less light;