1. Biotic components are the living things in an ecosystem, including producers, consumers, and decomposers. 2. Producers like plants use photosynthesis to obtain energy from sunlight. Consumers eat producers or other consumers to obtain energy, and can be herbivores, carnivores, or omnivores. Decomposers obtain energy from dead producers and consumers. 3. Food chains show the feeding relationships between organisms, with energy passing from producers to primary, secondary, and tertiary consumers.