Mutualism is the ecological interaction in which both participants benefit and that is obligatory for their SURVIVAL. Mutualism is a harmonious (positive) ecological interaction. Mutualism is also known as symbiosis. Examples of mutualism are: the association between microorganisms that digest cellulose and the ruminants or insects WITHIN which they live; the lichens, formed by algae or cyanobacteria that make organic material for the fungi and absorb WATER with their help; nitrifying bacteria of the genus Rhizobium that associated to LEGUMINOUS offer nitrogen to these plants.

Mutualism is the ecological interaction in which both participants benefit and that is obligatory for their survival. Mutualism is a harmonious (positive) ecological interaction. Mutualism is also known as symbiosis. Examples of mutualism are: the association between microorganisms that digest cellulose and the ruminants or insects within which they live; the lichens, formed by algae or cyanobacteria that make organic material for the fungi and absorb water with their help; nitrifying bacteria of the genus Rhizobium that associated to leguminous offer nitrogen to these plants.