A student is setting up a model to study the carbon cycle and natural sources of carbon dioxide. They create a microenvironment that contains soil, leaf debris, an earthworm, heterotrophic bacteria, and a sun lamp. What natural source of carbon dioxide and major metabolic process was left out of the model? i. There is no representation of decomposition in the model environment.
ii. There is no representation of cellular respiration in the model environment.
iii. There is no representation of photosynthesis in the model environment.
iv. There is no representation of ingestion in the model environment.