Relationships among
Populations
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Before watching the video, take time to read
over all the questions in the activity page
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While watching the video, fill in the answers to
your activity sheet
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Videohttp://player.discoveryeducation.com/index.cf
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 With
the people at your table
discuss the answers to the
Activity Sheet
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Intraspecific Competition: When members of the
same species compete for resources
Interspecific Competition: When members of
different species compete for resources
When organisms compete for resources they limit the
growth of a population
Predation: An interaction where one organism kills
and hunts another organism
Predation affects population size by decreasing the prey
population.
Predators adapt to catch their prey by avoiding prey
that may be distasteful or poisonous
Organisms adapt to avoid becoming prey through color
patterns, having bright colors to warn predators of their
poisonous nature or mimic colors of poisonous
organisms
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Symbiosis: a relationship in which two organisms of
different species live in close association and at least
one organism benefits
Parasitism: a symbiotic relationship where the parasite
benefits from the host by using some of its energy. This
relationship may or may not kill the organism
Mutualism: a symbiotic relationship where both
organisms benefit from the relationship
Being mutually beneficial can lead to interdependency
because on cannot survive without the other. Ex.
Commensalism: a symbiotic relationship where one
organism benefits and the other is not affected
Interactions
Species 1
Organism 1
Competition
Negative
Predator
Predation
Positive
Parasite
Parasitism
Positive
Organism 1
Mutualism
Positive
Commensal Organism
Commensalism
Positive
Species 2
Organism 2
Negative
Prey
Negative
Host
Negative
Organism 2
Positive
Organism 2
Neutral