- All organisms ultimately get their energy from the sun through photosynthesis carried out by producers like plants and algae or through consumption of other organisms. - There are different types of consumers in food chains including herbivores, carnivores, omnivores, and decomposers. Parasites also feed on other living organisms. - Food chains show the transfer of energy from producers to primary, secondary, and tertiary consumers and decomposers. Multiple interconnected food chains make up a food web.