1. Survival Relationships Predator-prey – Predators seek out and eat other organisms Competition—two species or organisms have niche overlap; they share food, water, shelter or mates; one will win and other must adapt through natural selection Symbiosis – A relationship in which there is a close and permanent association between organisms of different species.

2. Mutualism Symbiotic relationship in which both species benefit.

3. Parasitism A symbiotic relationship in which one organism benefits at the expense of the other. Trichinellosis Trichinella spiralis

4. Commensalism A symbiotic relationship where one species benefits and the other is neither harmed or helped. (many are now seen as undefined mutualism)

5. Survival Relationships Mutualism – is a symbiotic relationship in which both species benefit. (+/+) Commensalism – is a symbiotic relationship in which one species benefits and the other is neither harmed nor benefited. (+/0) Parasitism – is a symbiotic relationship in which one species benefits and the other is harmed (+/-)

6. Survival Relationships