Download Organisms can interact in different ways.

Organisms can interact in
different ways.
Chapter 2
Section 2
Predator and Prey
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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
Competition
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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
Cooperation
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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
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
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
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.
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.
Symbiotic Relationships
Mutualism
benefits both
Commensalism
benefits one, other unaffected
Parasitism
benefits one, harms other