1. Ecology Chapter 2 Section 2: Organism Interaction
Objectives:
1. Students can describe the different types of interactions within an ecosystem.
2. Students describe symbiotic relationships in which one or more species benefits.
3. Students will be able to describe symbiotic relationships in which one species is harmed.

2. Predator and Prey Many interactions in an ecosystem involve food.
A predator is an animal that eats another animal.
The prey is the animal that is eaten by the predator.
Organisms can be both predator and prey

3. Competition
Competition is the struggle between individuals of different populations for limited resources.
Competition may occur between the same species
Ex. – Wolves compete over territory
Competition may also occur between different species.
Ex.- Vultures and Hyenas compete over animal remains.
Organisms may compete over food, living spaces, water, and mates

4. Competition

5. Cooperation
Cooperation is an interaction between two or more organisms that are working together.
Organisms will use cooperation when hunting or taking care of their young.

6. Symbiosis
Symbiosis is the interaction between two individuals from two different species that live closely together.
There are three types of symbiosis
1. Mutualism
2. Commensalism
3. Parasitism

7. Mutualism
Mutualism is the interaction between two species that benefits both.
Ex. – Bees obtain nectar (food) from flowers and the flowers get pollen

8. Commensalism
Commensalism is the relationship between two species in which one benefits while the other is not affected.

9. Parasitism
Parasitism is a relationship between two species in which one benefits and the other is harmed.
They will live on or inside of their host
Parasites are often tiny creatures
Ex. – Ticks, lice, mites, mosquitoes
Parasites cause harm to their host, but usually do not kill their host.

10. Ecosystem Interactions Are Complex
Symbiosis is one of many interaction that take place in an ecosystem
An ecosystem is much more than a collection of biotic and abiotic factors.
These interactions help explain how resources are shared and used up and how energy flows through the ecosystem.