Biotic Factors

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Biotic Factors

• So far, we talked about
• Energy flows
• Abiotic factors
• Now, we will look at organisms actions in a
  community.

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Relationships in a Community

• Communities can not exist without relationships
  between organisms.
• How can 2 living things affect each other?
• Help both
• Help one, neither harm nor help the other
• Help one, harm one
• Help one, kill another ?

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Competition

• More than one organism tries to use a resource at
  the same time, in the same place.
• Resources organisms would compete for
• Water
• Food
• Space/Shelter
• Sunlight
• Mates

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Predation

• One organism captures and feeds on another.
• Predator- animal that hunts, kills and eats
  another animal
• Prey- The animal that is killed and eaten

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Symbiosis

• Relationship between two species that live
  closely together.
• There are 3 types are

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1. Mutualism

• Everyone benefits
• Example Clownfish (Anemonefish) and Anemone
• The clownfish is protected by the stinging
  Anemone
• The clownfish
• Cleans and Protects
• the Anemone from
• the Butterfly fish

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2. Commensalism

• One living thing is helped, the other doesnt get
  hurt
• hitch hikers
• Remoras often
• attach themselves to
• sharks, Manta rays
• turtles.
• They get a free ride and food
• They do not hurt the animal they attach to.

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3. Parasitism

• One organism benefits as it harms another.
• Parasites obtain all nutritional needs from host.
• Usually weakens host.
• Example bacteria, worms, bugs often feed on the
  blood or flesh of an animal
• Why would a parasite not want to kill its host?

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BIODIVERSITY THREAT

• One of most important threats to
• biodiversity come from apparently
• harmless plants or animals that
• humans transport into new habitats
• _____________________
• New habitats dont have ____________
• and parasites that control the population
• in their native habitats, so invasive species
• populations _____________ rapidly.

INVASIVE SPECIES
PREDATORS
INCREASE
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EXAMPLES OF INVASIVE SPECIES
Zebra mussels
_________________ are native to the Caspian Sea.
They are believed to have been transported to the
Great Lakes in the ballast water from a ship.
They were first discovered in 1988, and have
since spread rapidly to all of the Great Lakes
and waterways in many States.
http//en.wikipedia.org/wiki/ImageDreissena_polym
orpha3.jpg
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• PROBLEMS CAUSED BY ZEBRA MUSSELS
• Clog power plant and public water intakes and
  pipes, costing taxpayers millions of
  dollars Damage boat engines Blanket
  shorelines with their sharp shells and
  foul smell Consume available food for
• native species and smother
• native mussels Threaten water-based
• recreational activities

http//en.wikipedia.org/wiki/Zebra_mussel