What do heterotrophs primarily utilize for their carbon supply?

Heterotrophs are organisms that cannot produce their own food through photosynthesis or chemosynthesis and instead rely on consuming organic materials to obtain their carbon supply. This group includes animals, fungi, and many bacteria, which break down organic compounds from their environment—such as plants, other animals, and decomposing matter—into usable forms of energy and carbon for growth and development.

The essence of heterotrophic nutrition lies in its reliance on organic compounds, which contain carbon. Unlike autotrophs, which convert inorganic CO2 into organic compounds through photosynthesis, heterotrophs must extract carbon from already formed organic matter. This distinction is crucial in understanding the food web and nutrient cycling in ecosystems, where heterotrophs play a vital role in transforming organic material into energy and nutrients that can be utilized by other organisms.

In contrast, options referring to inorganic materials, carbon dioxide, and photosynthetic processes are associated with autotrophic organisms, which synthesize their own food from inorganic substances or through photosynthesis. Heterotrophs simply do not engage in these processes for their carbon supply.