According to the heterotroph hypothesis, some early heterotrophs evolved into autotrophs because of their ability to synthesize organic compounds from water and
A. Oxygen.
B. Hydrogen.
C. Carbon dioxide.
D. Hydrochloric acid.
E. Nitrogen.
Heterotrophs must ingest, digest, and egest preformed organic matter. Autotrophs evolved from heterotrophs by developing a way to make their own organic food by changing water and carbon dioxide into glucose.