Organisms of a community have many kinds of relationships with each other. These relationships include predator-prey relationships, competition and symbiosis.
Producers produce energy to their communities through photosynthesis.
A food chain always begin at the producer.
Consumers eat producers or consumers of lower degrees than them.
Decomposers, such as bacteria or crayfish, recycle dead organisms and transform them into nutrients.
In a food pyramid, organisms are placed according to their position in the food chain. The pyramid grows narrower towards the top: there are fewer high-degree consumers than there are producers or lower-degree consumers.
