1. Organisms can interact in different ways.
Chapter 2
Section 2

2. Predator and Prey Predator: an animal that eats another animal
Prey: an animal that is eaten by a predator
In a food chain, an animal can be both a predator and a prey

3. Competition
The struggle between individuals or different populations for a limited resource
Occurs between members of different species or
Occurs within the same species
Plants may compete with each other for light, space, and nutrients

4. Cooperation
An interaction in which organisms work in a way that benefits them all
Example: Ants, bees, and termites live in colonies. Members of the colonies have different responsibilities like gathering food or defending the colony

5. The survival of one species might depend on another species.
Symbiosis: relationship between individuals of two different species who live together in a close relationship
May affect the partners in different ways

6. Both species benefit
Mutualism: an interaction between two species that benefits both
Example: termites live off of wood – they have tiny singled celled protozoans living in their guts that help them digest the wood. The protozoans get a safe place to live, and the termites can take advantage of a plentiful food source

7. One Species Benefits
Commensalism: a relationship between two species in which one species benefits while the other is not affected
Example: Some fish protect themselves by swimming among the stinging tentacles of a moon jellyfish. The fish benefit because the tentacles keep them safe and the jellyfish is not helped or hurt by the presence of the fish.

8. One species is harmed
Parasitism: a relationship between two species in which one species benefits while the species it depends on, its host, is harmed.
Example: Parasites are often tiny organisms that feed off, and weaken, their hosts. Tapeworms and ringworms live inside their hosts.

9. Symbiotic Relationships
Mutualism
benefits both
Commensalism
benefits one, other unaffected
Parasitism
benefits one, harms other