The Carbon Cycle

Summary Questions p.90

  • The carbon dioxide concentration of the atmosphere is less on a summers’ day than on a winters’ day because more plants are photosynthesising in summer. This is because light is required for photosynthesis, and more light is available in summer, therefore the light dependent reaction can take place, providing ATP which transitions to the light independent reaction. In the Calvin Cycle, ribulose bisphosphate combines with atmospheric CO2 to create a 6-carbon compound. This is why more CO2 is taken from the atmosphere in summer.
  • A – Combustion

B – Respiration

C – Feeding

D – Photosynthesis

  • D best represents the carbon cycle.