Thursday, September 8, 2011

Movies on Population and Communities

Watched 2 movies.
Key points:
Movie #1: populations
Populations grow and change
different populations grow @ different rates
will always eventually stop
niche= way population gets thing it needs and interacts w/ surrounding area, other species
populations depend on each other
small organisms with high birthrates and a short life span typically have boom-bust growth cycles
Small Predators can have a greater impact on prey populations
some birds have behavior instincts that reduce crowding and competition
populations can be impacted by interactions w/ same species

Movie #2: Communities

can be open or closed
open=can have interactions w/ other communities
closed=residents are trapped
4 types of relationships: Symbiotic, parasitism, mutualism and cominsolism sorry don't know how 2 spell :(
Symbiotic= species are totally dependent on each other
cominsolism=one benefits, other is unharmed
parasitism=one benefits, other is harmed/killed
if killed=predation
mutualism=both benefit

Next scribe: JakeP

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