Symbiotic Relationships

Symbiotic Relationships
Symbiosis
• A close relationship between two specie
that benefits at least one of the species.
• Four types are: mutualism,
commensalism, parasitism, and
amensalism
Mutualism
• A relationship in which both species benefit.
Represented by +/+
• Examples:
Saguaro Cactus and Long-eared bats. The bat
benefits because the cactus flowers provide it
with food and the cactus benefits because the
bat carries the cactus’ pollen on its nose.
Humans and bacteria in our large intestine.
Bacteria helps break down food that we can’t
always digest and also gives us Vitamin K and
the bacteria receive food to eat.
MUTUALISM
• One of the most
commonly observed
mutualism is the
pollination of flowering
plants by an insect or
humming bird.
• The pollinator benefits
from the interaction by
receiving nectar.
• The plant gets its pollen
transferred from one
plant to another.
MUTUALISM
• The lichen is a mutualistic
association between a
species of algae and a
species of fungus.
• The fungus retains water
and takes up minerals.
• The algae provides
carbohydrates and other
organic nutrients as the
result of photosynthesis.
MUTUALISM
• Some species of ants and
treehoppers form an
interesting mutualism that
resembles tending (care
giving).
• The ants provide
protection for the
treehoppers.
• In turn, the treehoppers
provide honeydew for the
ants.
Commensalism
• A relationship in which one species
benefits and the other species is neither
helped nor harmed. Represented by +/0
• This is not very common because in most
relationships the species are either helped
or harmed at least a little bit
• Example: Red-Tailed Hawks and Saguaro
Cactus. The hawks have a place to build
their nest, but the cactus is not harmed.
Other examples of
commensalistic
relationships:
Barnacles adhering to the
skin of a whale : The
barnacle benefits by filtering
food as the whale swims. Its
does not seem to affect the
whale.
Sea Anemone and
Clownfish: Clown fish gets
http://www.youtube.com/watch?v=eWX
OurnVTYg
protection Anemone is
unaffected
COMMENSALISM
• The cattle egret and
cattle or other
grazing African
ungulate species.
• The egret benefits
from catching
insects that cattle
“scare-up” while
grazing.
• Cattle unaffected.
COMMENSALISM
• E. coli (Escherichia coli) is
a common bacteria found
living in the guts of
mammals, including
humans, where it gets all
it needs to thrive.
• In most circumstances,
humans are not harmed
by its presence and no
benefit has been
discovered.
COMMENSALISM
• Bromeliads are a
group of flowering
plants that attach to
trees (epiphytes).
They gain access to
sunlight and catch
water.
• The trees are not
harmed or
benefited.
Parasitism
• This relationship involves one organism living on
or inside another organism and harming it.
Represented by +/• The organism that benefits is called a parasite
and the organism that is harmed is called a host.
• A parasite will not usually kill its host because
then it loses its source of food.
• Example: Ticks. They attach to a host on feed
on its blood.
Parasitism Examples:
A) Ants and Acacia Tree: lay eggs on
acacia tree, Acacia covers the infected
area with brown flesh (gall)
B) Tapeworm and Cow: They get food by
eating the host's partly digested food,
depriving the host of nutrients.
C) Fleas and Cats: fleas bite the Cats skin,
sucking their blood, and causing them to
itch and possible get sick. The fleas, in
turn, get food and a warm home.
D) Wasp eggs on back of
caterpillar.
Parasitism
E) Sea lampreys feed on
fluids of other fish.
F) Mosquito biting a
human.
Amensalism
• A type of symbiotic relationship in which one
organism restricts the success of the other
without being positively or negatively affected by
its presence
• Represented by -/0
• There are two basic modes:
– competition, in which a larger or stronger organism
excludes a smaller or weaker one from living space or
deprives it of food
– antibiosis, in which one organism is unaffected but
the other is damaged or killed by a chemical
secretion.
Amensalism Examples
• The classic demonstration of antibiosis is the
destructive effect that the bread mold
Penicillium has upon certain bacteria; the
secretion, known as penicillin, has become a
potent medicine in combating bacterial
infections.
• Some higher plants secrete substances that
inhibit the growth of—or kill outright—nearby
competing plants. An example is the black
walnut (Juglans nigra), which secretes juglone,
a substance that destroys many herbaceous
plants within its root zone.
Amensalism Examples
• A) Penicillium and bacteria:
penicillium secretes penicillin, a
chemical that kills bacteria.
• B) Black Walnut Tree and other
plants: The Black Walnut gives off a
chemical that harms or kills some
species of neighboring plants.
• C) Sheep and grass: Sheep make
trails by trampling on thereby
destroying a food source.
Symbiosis and You
• What is one example
of mutualism that a
person might be
involved in?
• What is one example
of commensalism that
a person might be
involved in?
• What is one example
of parasitism that a
person might be
involved in?
Symbiosis and You
• Think about your
friends.
– What would a
mutualist friend be
like?
– What would a
commensalist friend
be like?
– What would a parasitic
friend be like?
– What type of friend are
you?
Don’t forget there are other
ways organisms interact……..
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Predation
Competition
Producer/Consumer/Decomposer
Carrying Capacity
Limiting Factors
Predation – one species feeds on another
 Enhances fitness of predator but reduces fitness
of prey
Herbivory is a form of
predation
Predation
Examples:
A) Cattle and grass: Cows eat
and kill the grass for food.
B) Wolf and Deer: Wolf kills
and eats deer for food
C) Baleen Whale and
plankton: Whale filters
plankton from water as it
swims.
D) Lynx and
Snowshoe
Hare:
As you can see
by the graph,
their
populations are
directly linked.
Competition – two species share a limited
resource
 reduces fitness of one or both species
Here are 3 examples
of competition
relationships:
A. Spruce and Pine Tree:
They must compete for light,
water and nutrients.
B. Cheetahs and Lions.
They must compete for the
same prey such as zebras.
C. Coyotes and bobcats:
They compete for the same
prey such as rabbits.
Competition
relationships continued:
D. Hyenas and Lions in
Africa: fight over gazelle
E. Rams: compete with
each other for mates.
F. Gray Squirrels and Red Squirrels: Until Americans introduced gray
squirrels into parts of England in the early 20th century, red squirrels
had been the only species of squirrel in the country. The gray squirrels
were larger and bred faster and successfully competed for resources.
Within a couple years of overlap in an area, the red squirrels
disappeared.
Producer/consumer/decomposer
• We’ve already
learned that a
producer is able to
use the sun’s energy
to make food.
• We’ve also learned
that a consumer has
to get food by eating
producers (herbivore)
or other consumers
(carnivore) or both,
(omnivore).
Producer/consumer/decomposer
• Producers
(autotrophs) capture
the energy that all
other organisms rely
on to survive.
• Without producers,
the sun’s energy
couldn’t be used by
living things.
Producer/consumer/decomposer
• A decomposer is an
organism that breaks
down waste and dead
organisms.
• Decomposers help to
recycle nutrients.
• Without
decomposers, dead
things would pile up,
and nutrients would
run out.
Producer/consumer/decomposer
• Are each of these
organisms a
producer, consumer,
or decomposer?
Carrying capacity
• The maximum
amount of individuals
of a certain species
that an environment
can support is called
the carrying
capacity.
Carrying capacity
• Example: Eurasian
Collared Doves in
Cache Valley
Limiting factor
• The resource that runs out
when a population
reaches its carrying
capacity is called the
limiting factor.
• Limiting factors lead to
competition between
organisms.