Relier Pairs Define Ecological RelationshipVersion en ligne Define Ecological Relationships par Amanda O'Malley 1 Mutualism 2 Commensalism 3 Parasitism 4 Competition 5 Predation One organism is harmed and the other benefits. Organisms competing for the same limited resource. Both organisms benefit by their association with eachother. One organism eats another organism. One organism benefits, the other is neutral (unharmed but does not benefit).