Download Relationships Among Organisms

Relationships Among
Organisms
Symbiosis
Terms
• Ecosystem: all the organisms living in
an area and everything that affects
them.
– Stable Ecosystem: the population sizes
and available resources cycle regularly or
change predictable and energy flows at
a fairly constant rate.
Terms
• Habitat: the place where an organism
lives.
• Niche: organism’s role in its
community.
Terms
• Symbiosis: an interdependent
relationship between organism of two
different species.
– Mutualism
– Commensalism
– Parasitism
Mutualism
• Both organisms benefit. (+,+)
– Each species helps the other survive.
Commensalism
• One organism benefits and the other is
not effected. It gets no benefit and is
not harmed. (+,0)
Parasitism
• One organism benefits (parasite) and
the other organism is harmed.
– The organism in which a parasite lives is
called the host.
– The host is NOT killed!
Mimicry
• One organism
attempts to look
like the other.
• The copied
organism
usually has a
beneficial trait,
such as being
poisonous
Predation
• Predation:
Interaction in which
one organism kills
and eats another.
– Predator: organism
that obtains the food.
– Prey: organism that is
killed and eaten.
– Example: Which is the
predator and prey in
this example?
Predator vs. Prey Populations
Competition
• Competition:
interaction in
which two or
more organisms
try to use the
same resources
at the same
time.