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.

Ecology Chapter 2 Section 2: Organism Interaction

Predator and PreyMany 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

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

Competition

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.

Symbiosis

Symbiosis is the interaction between two individuals from two different species that live closely together.

There are three types of symbiosis1. Mutualism2. Commensalism3. Parasitism

Mutualism Mutualism is the interaction between two species

that benefits both. Ex. – Bees obtain nectar (food) from flowers and

the flowers get pollen

Commensalism Commensalism is the relationship

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

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.

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.