A biological food chain is an abstract model used to look at the relationships between biological life forms. The food chain outlines the nutritional relationships between biological organisms in linear form from “primary producer” to the “top” of the food chain. Primary producers organize specific atoms, molecules and energy sources like sunlight or heat into what we know as biology. Photosynthetic organisms like plants algae and phytoplankton are examples of primary producers in a food chain. These primary life forms then support many other species in the “food chain” either directly or indirectly through a series of feeding relationships. Food chains are constructed with links from primary producers through primary consumers secondary consumers and so on to what is called the “top” of the food chain. At the top of the chain is a species that has no other species that feeds on it. Terms like “King of the Jungle” are used to describe such a top feeder on the food chain. In a lake environment, a fish might take the top tier of the food chain.
Like most models, the “food chain” is useful, but it has limitations at illustrating the whole image of the relationships that define biology. Even though primary producers act as a clear bridge from non-biological processes to biological ones, the total biological economy can be more accurately represented using a nonlinear web as the model rather than a linear chain. This is because there are many tangled and cross referenced relationships in a food web. A web could have more than one primary producer and these can be cross linked in numerous ways throughout the interdependent system. Even with a sole primary producer, interdependent biological systems (called a biomes or ecosystems) are not a strict linear route from bottom to top as a “food chain” model implies.
So let’s listen to what this web of biological relationships says; a primary producer species is an umbilical cord that feeds on the broader womb of non-biological reality. It translates a non-biological system into a biological one. The same way the letters and phrases that compose this communication are based on a certain order of relationships to each other that gives rise to meaning, primary producers channel matter and energy into the complex organized interdependent relationship systems we know as biology. The term organism is fitting for biological systems of all types because of this fact.
While there are so many things communicated through the fantastic relationship dynamic that gives rise to biology, one statement that stands out is the fact that reality is the womb from which we are formed and draw our nourishment. Have you hugged your Reality today?
 The idea was introduced by the African-Arab scientist and philosopher Al-Jahiz in the 9th century ACE.
 In addition to photosynthetic organisms there are also chemosynthetic primary producer organisms that use heat and chemicals as the basis of conversion of inorganic to organic biomass.
 Non-feeding relationships also exist between biological organisms. These can be broadly categorized as cooperative and/or competitive.
 Predators can be infected with such things as parasites and destructive viruses, so the notion that the top is undisputed top is a bit of a misnomer.
 Non-biological sometimes called abiotic and biological called biotic structure in ecosystems.
 There are three feeding type relationships typically defined in biology. These are the food chain, the food web, and trophic levels.