1. Autotrophs vs Heterotrophs

2. Autotrophs
Autotrophs are organisms that can produce their own food from the substances available in their surroundings using light (photosynthesis) or chemical energy (chemosynthesis).
An autotroph is an organism that is able to form nutritional organic substances – ex: plants, algae, and some bacteria.
They are often called “self feeders” or “primary producers” that obtain carbon from inorganic sources like carbon dioxide (CO2).

3. Heterotrophs
Heterotrophs cannot make their own food and rely on other organisms – both plants and animals – for nutrition.
Heterotrophs get their reduced carbon from other organisms.
Basically – heterotrophs depend on autotrophs and other heterotrophs.
Herbivores, omnivores, and carnivores are all heterotrophs.

4. Food Chain

5. Food Chain
Autotrophs are primary producers that are placed first in the food chain.
Heterotrophs that depend on autotrophs and other heterotrophs for their energy level are placed next on the food chain.
Herbivores that feed on autotrophs are placed in the second trophic level. Carnivores that eat meat and omnivores that eat all types of organisms are placed next in the tropic level.