Which of the Following are Responsible for the CO₂-Fixation Component

Question

Which of the following are responsible for the CO₂-fixation component of the carbon cycle?
A) heterotrophs
B) symbionts
C) autotrophs
D) chemotrophs
E) organotrophs

Accepted Answer

Autotrophs are the organisms responsible for the CO₂-fixation component of the carbon cycle, as they are able to convert inorganic carbon into organic molecules using energy from the sun (in photosynthesis) or from chemical reactions (in chemosynthesis). Heterotrophs (A) obtain their carbon from organic sources, while symbionts (B) can be either autotrophic or heterotrophic, but are not directly involved in the CO₂-fixation component of the cycle. Chemotrophs (D) and organotrophs (E) also obtain their energy and carbon from organic sources, and are not responsible for fixing carbon from the atmosphere.