A symbiotic relationship is a relationship between two different living organisms. I can be categorized as mutualistic, commensal, or parasitic. Mutualism or a mutualistic symbiotic relationship is when two organisms both benefit from the relationship. Commensalism is where one benefits and the other is not significantly harmed nor helped. Parasitism is where one benefits and the other is harmed.
An example of mutualism is ants and aphids. Ants protect aphids from predators and, in exchange, ants benefit from eating the 'honeydew' excreted by the aphids.
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