Download Symbiotic Relationships

Practice/Application
Symbiotic
Relationships
Symbiotic Relationships:
An Introduction
O Click on the picture
of the leaf cutter at
the left or on this
link to view a video
about symbiosis.
Leaf cutter video
O You must be
connected to the
Internet to view
this video.
Symbiotic Relationships
O Definition: A relationship between two
kinds of organisms that lasts over a
period of time is called symbiosis.
O The word symbiosis can be broken down
into two parts to determine its meaning.
O sym means together (like in the words sympathy and
symphony)
O bio means life (like in the words biology and biome)
Types of Symbiosis
O There are five types of
symbiotic relationships.
O Each relationship can be
shown using + - or 0.
O Parasitism
O Mutualism
O Commensalism
O Neutralism
O Competition
O The chart below shows
these relationships.
Parasitism
O Parasitism is the
situation where one
organism benefits
while the other is
harmed.
O A + / - relationship.
Parasitic Isopod on fish
Commensalism
O Commensalism is
where one species
benefits while the
second species
remains unaffected.
O A + / 0 relationship
Barnacles adhering to the skin of
a whale
Mutualism
O Mutualism is where
both organisms
benefit from the
relationship.
O A + / + relationship.
The clownfish and sea anemone are an example of
mutualism. Although these anemones stun and
devour other species of fish, clownfish are not
harmed. Clownfishes were thought to be commensal
on the giant sea anemones, but there now is
evidence that the aggressively territorial
clownfishes chase away butterfly fishes, who eat
anemone tentacles.
Predation
O Predation is where
a predator feeds
on its prey for
food and energy.
One organism
benefits while the
other is harmed.
A South China tiger (Panthera tigris
amoyensis) as the predator feeding on
the blesbuck as the prey
O A+/-
relationship.
Neutralism and Competition
O Neutralism is
the situation
where both
species remain
unaffected.
OA 0 / 0
relationship.
O Competition is
where neither
species
benefits.
OA - / relationship.
Now Try this
A lion stalks a herd of antelope wading in a pond. A flock
of water birds on the shore become startled by the sound
of the lion’s approach and fly away with a great deal of
noise. The bird’s sudden departure gives warning to the
antelope, and they are also able to escape safely. What
type of relationship exists between the birds and the
antelope?
a)
b)
c)
d)
e)
Competition
Mutualism
Commensalism
Parasitism
Predation
Try again
O For a relationship to be competition,
the end result on both sides of the
relationship is a negative. This isn’t the
case in this relationship.
O Return to the question.
Not quite
O If the relationship was mutualistic, then
both sides of the relationship would
have a positive result from the
relationship. While the antelope did
have a positive from the birds (the
warning) the birds didn’t get a positive
from the antelope.
O Return to the question.
You are CORRECT!
O In the antelope and water bird
relationship, the antelope gets a
warning of the coming danger (+) the
water birds don’t get anything from the
antelope though.
O Next example
Think about this again
O For a relationship to be parasitic, one
organism benefits from the relationship
while the other has negative effects
from the relationship. In this example
the only negative is for the lion, but we
are looking at the antelope and water
birds.
O Return to the question.
For Practice
A lichen is a combination of two organisms, an alga and a
fungus. The fungus gets its food from the alga while the
alga gets water from the fungus. This is an example of
which relationship?
a) Competition
b) Mutualism
c) Parasitism
d) Commensalism
e) Predation
Let’s look at this again
O If this were an example of competition,
both of the organisms would be
effected negatively. However, in this
example neither organism is effected
negatively.
O Return to the question.
Good Job!
O You’re right! This is an example of a
mutualistic relationship. The alga gains
water from the fungus and the fungus
gains food from the alga. Both need
each other to live and gain something
from the other organism.
It’s interesting that you
think this
O In a parasitic relationship, one organism
gains a positive while the other
organism receives a negative. In this
example, neither organism receives a
negative.
O Return to the question.
Can we talk about the
example
O In a commensalistic relationship, one
organism gains something positive. The
other organism remains unaffected by
the relationship. In this example, both
organisms are effected by the
relationship.
O Return to the question.