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