Plants produce oxygen by photosynthesis. By this same mechanism, plants transform mineral carbon into organic carbon usable by animals. Plants are autotrophic (self nourishing: producers) contrasting with the heterotrophic animals (consuming other living things: consumers). The plants are thus a paramount element of any food chain. Plants allow many animal species to live: either as being their host, or as food. It is thus possible to design food chains without animals but there are none (...)