Final answer:
Autotrophs, like plants, algae, and certain bacteria, can make their own food through photosynthesis or other means, and are critical for supporting food chains.
Step-by-step explanation:
Organisms that can make their own food are known as autotrophs. These include not only plants but also algae and a specific group of bacteria known as cyanobacteria. These autotrophs can carry out photosynthesis, a process that converts light energy into chemical energy in the form of glucose or other sugars. Plants are considered photoautotrophs because they harness solar energy for photosynthesis. Furthermore, there are some bacteria that can synthesize their own food using energy derived from inorganic chemical compounds, making them chemoautotrophs. In contrast, organisms like animals and fungi that cannot make their own food are called heterotrophs. Autotrophs form the foundation of food chains by producing food not only for themselves but also for these heterotrophic organisms.