How do autotrophs acquire energy?

Autotrophs acquire energy primarily through the processes of photosynthesis or chemosynthesis. Photosynthesis occurs in organisms like plants, algae, and some bacteria, which use sunlight, carbon dioxide, and water to produce glucose and oxygen. This process converts light energy into chemical energy stored in the form of glucose, which can then be used for growth, reproduction, and other vital functions.

On the other hand, chemosynthesis is employed by certain bacteria and archaea that extract energy from inorganic molecules rather than light. These organisms typically inhabit extreme environments, such as deep-sea hydrothermal vents, where they utilize sulfur or nitrogen compounds to produce organic compounds from carbon dioxide.

Together, these processes enable autotrophs to synthesize their own food, making them primary producers in ecosystems and serving as a critical energy source for heterotrophs, which do depend on consuming other organisms for energy. The other options focus on different mechanisms of energy acquisition used by heterotrophs or do not accurately describe how autotrophs obtain their energy.