<P> The three basic ways in which organisms get food are as producers, consumers and decomposers . </P> <Ul> <Li> Producers (autotrophs) are typically plants or algae . Plants and algae do not usually eat other organisms, but pull nutrients from the soil or the ocean and manufacture their own food using photosynthesis . For this reason, they are called primary producers . In this way, it is energy from the sun that usually powers the base of the food chain . An exception occurs in deep - sea hydrothermal ecosystems, where there is no sunlight . Here primary producers manufacture food through a process called chemosynthesis . </Li> <Li> Consumers (heterotrophs) are species that cannot manufacture their own food and need to consume other organisms . Animals that eat primary producers (like plants) are called herbivores . Animals that eat other animals are called carnivores, and animals that eat both plant and other animals are called omnivores . </Li> <Li> Decomposers (detritivores) break down dead plant and animal material and wastes and release it again as energy and nutrients into the ecosystem for recycling . Decomposers, such as bacteria and fungi (mushrooms), feed on waste and dead matter, converting it into inorganic chemicals that can be recycled as mineral nutrients for plants to use again . </Li> </Ul> <Li> Producers (autotrophs) are typically plants or algae . Plants and algae do not usually eat other organisms, but pull nutrients from the soil or the ocean and manufacture their own food using photosynthesis . For this reason, they are called primary producers . In this way, it is energy from the sun that usually powers the base of the food chain . An exception occurs in deep - sea hydrothermal ecosystems, where there is no sunlight . Here primary producers manufacture food through a process called chemosynthesis . </Li> <Li> Consumers (heterotrophs) are species that cannot manufacture their own food and need to consume other organisms . Animals that eat primary producers (like plants) are called herbivores . Animals that eat other animals are called carnivores, and animals that eat both plant and other animals are called omnivores . </Li>

Which type of organism produces food in an ecosystem