3 main ways organisms interact with each other:1. Competition2. Predation3. Symbiosis

Mutualism – both species benefit from the partnership

eg. the caterpillars have nectar organs which the ants drink from and the acacia tolerates the feeding caterpillars. The ants provide protection for both the plantand the caterpillar

Commensalism – one species benefits from the relationship and the other lives without any harm or benefit

eg. the bird gets food from the cow’s back but the cow is unaffected

Parasitism – one species benefits at the expense of another (a parasite lives in or on another organism) ex. the tick feeds off the dog’s blood

1. Classify the following interactions as mutualism, commensalism, or parasitism.

a) A yucca moth caterpillar feeds on the yucca plant and pollinates the yucca plant.

b) Lice feed harmlessly on the feathers of birds.c) A cowbird removes an egg from a robin’s nest and replaces

it with one of its own.d) An orchid plant grows on the branch of a tree. The tree

remains healthy.2. When similar species live in the same habitat, explain how

competition between these species is reduced. 3. When a predator catches its prey, it may appear that the prey

species suffers. But there are benefits to this type of interaction for the prey species as well. What are two ways in which the prey species may benefit from the predator hunting them?