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