Interactions in Communities
How Organisms Interact
Competition, Predation
How Organisms Interact
Competition
Organisms of the same or different species attempt to use the same ecological resource (food, water, space) in the same place at the same time.
Example:
How Organisms Interact
Predation
Interaction in which one organism (predator) captures and feeds on another organism (prey)
Example:
Symbiosis:
Any relationship in which two species live closely together
3 Types of Symbiotic Relationships
Mutualism, Commensalism, Parasitism
3 Types of Symbiotic Relationships
Mutualism (+, +)
Both organisms benefit
Examples:
3 Types of Symbiotic Relationships
Commensalism (+, 0)
One organism benefits, the other is unaffected
Examples:
3 Types of Symbiotic Relationships
Parasitism (+, -)
One organism (parasite) benefits, the other (host) is harmed. The parasite obtains nutrition from the host.
Examples:
Name That Relationship!
A hummingbird feeds on the nectar of flowering plants, while spreading the plant’s pollen to other flowers.
Mutualism (+, +)
A cattle bird feeds on insects stirred up by the feet of the cows that they live with.
Commensalism (+, 0)
Mistletoe grows in an elm tree, absorbing nutrients meant for the branches.
Parasitism (+, -)
A desert wasp shoots its eggs into the burrows of bees, where they hatch into larvae and feed on the bee’s eggs.
Parasitism (+, -)
Name That Relationship!
E coli bacteria live in the large intestine of humans. They receive nutrients from food wasts and produce vitamin D which is absorbed by the host.
Mutualism (+, +)
The stinging tentacles of the sea anemone protect pairs of clown fish. In return, the clown fish clean debris from the sea anemone.
Strangler figs start when a bird or a fruit bat drops a seed onto a live tree. Its roots quickly grow downward, choking the host tree and taking its nutrients, while its crown grows upwards, stealing sunlight.
Parasitism (+, -)
Mutualism (+, +)