Ecology Chapter 15 Mutualism and Commensalism

positive interactions

one or both species benefit and neither is harmed

mutualism

beneficial interaction between individuals of two or more species

mutualism(2)

(+/+)

commensalism

interaction in which individuals on one species benefit, while those of the other species do not benefit and are not harmed

commensalism(2)

(+/0)

symbiosis

a relationship in which individuals of the two species live in close physical and/or physiological contact with each other

mycorrhizae

symbiotic associations between plant roots and various types of fungi that are usually mutualistic

ectomycorrhizae

fungal partner typically grows between root cells and forms a small mantle around the exterior of the root(shell around root)

arbuscular mycorrihzae

grows into the soil, and grows between some roots cells while penetrating the cell walls of others(branches into roots)

trophic mutualism

a mutualist receives energy or nutrients from its partner

habitat mutualisms

one partner provides the other with shelter, a place to live, or favorable habitat

cheaters

individuals that increase their production of offspring by overexploiting their mutualistic partner