Final answer:
An organism is classified as a heterotroph or autotroph based on its source of nutrition. Autotrophs convert inorganic carbon dioxide into organic carbon compounds, while heterotrophs rely on complex organic carbon compounds as nutrients, initially provided by autotrophs.
Step-by-step explanation:
An organism is classified as a heterotroph or autotroph based on its source of nutrition. Autotrophs are organisms that convert inorganic carbon dioxide (CO₂) into organic carbon compounds, while heterotrophs rely on complex organic carbon compounds as nutrients, initially provided by autotrophs. Examples of autotrophs include plants and cyanobacteria, while humans and many prokaryotes are examples of heterotrophs.