1. Ecosystem Interactions
The 3 main types of biotic interactions are:
Competition
Predation
Symbiosis

2. Competition
is the interaction between two or more organisms for the same resource in a given habitat.
Ex. Male mountain goats who compete to mate.

3. Competition
For similar species to coexist in the same habitat, they must have slightly different niches.
They must not compete for the same resources.
A niche is the role an organism plays in an ecosystem.

4. Predation
Occurs when one organism eats another organism to obtain food.
Many animals use camouflage to avoid predators.

5. Predation Some species use mimicry to avoid predators.
Ex. The viceroy butterfly looks like the monarch. Monarchs taste foul and they have a greater chance of not being eaten because their predators avoid them.

6. Symbiosis Is a close interaction between two different species.
Three types of symbiosis are:
Mutualism
Commensalism
Parasitism

7. A. Mutualism Both species benefit from the partnership.
Ex. Leaf cutter ants harvest leaves and feed them to a fungus in their nest. The fungus is then feed to the leaf cutter larvae. The ants live off the leaf sap.

8. B. Commensalism One species benefits from a relationship.
The second species is not harmed nor benefits.
Ex. Bird building a nest in a tree, the bird benefits and nothing happens to the tree

9. C. Parasitism
The parasite benefits at the expense of the host species.
The malaria parasite benefits at the expense of the human host.

10. Characteristics of Populations
Eventually the number of births and deaths in a population balance out.
The carrying capacity is the maximum number of individuals of a population that an ecosystem has resources to support.

11. Factors that affect Populations in Ecosystems
A limiting factor is an environmental factor that prevents an increase in the number of organisms in a population.
Abiotic factors: water, sunlight, fires, logging, droughts
Biotic factors: predators, competition for resources, disease

12. Predator Prey Simulation
ems/oscillation/Oscillation_PredpreyA.asp