Interactions of Organisms

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Interactions of Organisms

• Competition
• Predator-Prey
• Symbiosis

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Youve 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

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Competitve Exclusion Principle

• No two species can occupy the same ecological
  niche at the same time if resources are limiting
• This leads to

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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.
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Symbiosis (table 33.2)

• Refers to close interactions between members of
  two populations.
• Three types
• Parasitism
• Commensalism
• Mutualism

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Parasitism

• A symbiotic relationship in which the parasite
  derives nourishment from another organism called
  the host
• Exs ticks, tape worms, bacteria

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Throughout their breeding range, monarch
butterflies are infected with a protozoan
parasite, Ophryocystis elektroscirrha.

• Which organism is the host?
• Does the monarch gain anything from this
  relationship?

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Commensalism

• 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

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Mutualism

• A symbiotic relationship in which both members of
  the association benefit
• Not always equally beneficial
• Ex(next slide)

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Plants and animal pollinators

• The insect gets the nectar and the flower gets to
  spread its pollen.

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Predator - Prey

• Predators feed on Prey
• Ex- lynx and hare

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Predator-Prey Population Dynamics

• Predator/Prey Populations cycle
• Why doesnt the hare just go extinct?
• As the lynx eats too many hare, and the
  population diminishesit eats another food source
  until the hare population increases again.

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Which of the following relationships is shown
below?

• Predator-Prey
• Competition
• Parasitism
• Commensalism
• Mutualism

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What kind of relationship is shown below?

• Competition
• Predator-Prey
• Commensalism
• Mutualism
• Parasitism

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?

• Competition
• Predator-Prey
• Parasitism
• Commensalism
• Mutualism

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What kind of relationship is shown below?

• Competition
• Predator-Prey
• Commensalism
• Mutualism
• Parasitism

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.