- Mutualism:
- Lichens: a symbiotic relationship between a fungus and an alga. The fungus provides a protective structure for the alga, while the alga provides the fungus with food through photosynthesis.
_Example:_ Reindeer lichen
- Commensalism:
- Arctic hare and polar bear: the arctic hare provides food for the polar bear, while the polar bear provides protection for the arctic hare by scaring away predators.
_Example:_ Arctic fox and snowy owl
- Parasitism:
- Parasitic worms and caribou: parasitic worms live in the caribou's body and feed on its blood and tissues, causing harm to the caribou.
_Example_: Botflies and caribou