Transcript Interactions of Organisms

Interactions of Organisms
Competition
Predator-Prey
Symbiosis
You’ve found your niche!

Ecological niche-
the role and position a
species has in its environment – how it meets its
needs for food and shelter, how it survives, and
how it reproduces.
• Includes all its interactions with the biotic and
abiotic parts of its habitat.
•
Habitat- where an organism lives
Competitve Exclusion Principle
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No two species can occupy the same
ecological niche at the same time if
resources are limiting…
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This leads to…
Competition
Occurs when organisms
try to utilize a resource
that is in limited supply
• Ex-light, space, nutrients
Ecologists say that all of the
plants in the forest are in
competition with each other;
they are competing for the
sunlight. In a dense forest,
many seedlings which
germinated in the spring may
not survive the winter
because they did not receive
enough sunlight to make and
store food.
Symbiosis (table 33.2)
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Refers to close
interactions
between
members of two
populations.
Three types:
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•
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Parasitism
Commensalism
Mutualism
Species 1
Parasitism
Commensalism
Mutualism
Species 2
ex
Parasitism
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A symbiotic relationship in which the
parasite derives nourishment from
another organism called the host
Ex’s: ticks, tape worms, bacteria
Throughout their breeding range, monarch butterflies are
infected with a protozoan parasite, Ophryocystis
elektroscirrha.

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Which
organism is
the host?
Does the
monarch
gain anything
from this
relationship?
Commensalism
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A symbiotic relationship between two
species in which one species benefits
and the other is neither benefited nor
harmed.
Ex- barnacles on the backs of whales
Mutualism

A symbiotic relationship in which both
members of the association benefit
• Not always equally beneficial
• Ex…(next slide)
Plants and animal pollinators

The insect gets the
nectar and the flower
gets to spread it’s
pollen.
Predator - Prey
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Predators feed on Prey
Ex- lynx and hare…
Predator-Prey Population
Dynamics…
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Predator/Prey
Populations cycle
Why doesn’t the hare
just go extinct?
As the lynx eats too
many hare, and the
population
diminishes…it eats
another food source
until the hare
population increases
again.
Species 1
Species 2
Parasitism
Benefits
Harmed
Commensalism
Benefits
No effect
Mutualism
Benefits
Benefits
example
Which of the following
relationships is shown below?
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m
lis
m
ut
ua
lis
M
sa
C
om
m
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Pr
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1
m
20% 20% 20% 20% 20%
at
or
-P
re
y
5.
ra
s
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tit
io
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Pa
2.
Predator-Prey
Competition
Parasitism
Commensalism
Mutualism
om
pe
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What kind of relationship is
shown below?
Competition
Predator-Prey
Commensalism
Mutualism
Parasitism
20%
1.
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2.
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5.
20%
The sea anemone has
poisonous tentacles that
protect the clown fish from
predators, but the anemone
is not hurt.
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Which of the following
relationships is shown below?
20%
20%
Competition
Predator-Prey
Parasitism
Commensalism
Mutualism
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2.
20% 3.
20% 4.
20% 5.
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What kind of relationship is
shown below?
Competition
Predator-Prey
Commensalism
Mutualism
Parasitism
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2.
3.
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5.
Lichens are formed because of a
relationship between a fungus and an
algae. The fungus conserves water and
leeches nutrients for the algae who in turn
photosynthesizes food for the fungus.
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P
ar
a
si
t is
m
is
m
ut
ua
l
m
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M
m
en
sa
l is
or
-
om
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C
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da
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P
om
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t it
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