Organisms that rely on other organisms for their energy and food supply are called heterotrophs.

Here's a breakdown:

* Heterotrophs cannot produce their own food through photosynthesis like plants do. They obtain their energy by consuming other organisms.

* Autotrophs, on the other hand, are organisms like plants that can produce their own food using sunlight, water, and carbon dioxide.

Examples of heterotrophs include:

* Animals: They eat plants (herbivores), other animals (carnivores), or a combination of both (omnivores).

* Fungi: They obtain nutrients by decomposing dead organic matter.

* Many bacteria: They consume a variety of organic substances.

Heterotrophs play a crucial role in the ecosystem by consuming and breaking down organic matter, returning nutrients to the environment and supporting food webs.