Download 35.4 Species interact in biological communities

35.4 Species interact in
biological communities
Objectives
• Identify causes and possible results of
interspecific competition.
• Identify some adaptations of predators and
prey.
• Compare and contrast symbiotic
relationships.
Vocabulary
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interspecific competition
competitive exclusion
niche
predation
symbiotic relationship
parasitism
mutualism
commensalism
Competition Between Species
• Remember…?
– community: a group of species living in the
same geographic area
– competition may limit population growth
• interspecific competition: competition
between species
– same resource
Competitive Exclusion
• One may succeed over the other.
• may not be an issue: predation
Niches
• niche: the unique living arrangement of a
species in a community
– habitat
– food sources
– time of day most active
– et cetera (Latin: “and other things”)
• rare to have two identical niches in one
place
Predation
• predation: an interaction in which one
organism eats another
Predator Adaptations
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fast
agile
coloring
behavior
good senses
physical structures
Prey Adaptations
• behavior
• coloring
– camouflage
– warning
– mimicry
• plants
– poisonous chemicals
– spines/thorns
Symbiotic Relationships
• close interaction between species in which
one of the species live in or on the other
• 3 types
– parasitism
– mutualism
– commensalism
Parasitism
• one obtains food at the expense of the other
• parasite benefits
• host is harmed
• usually takes time to kill host
• some hosts have adaptations to avoid
Mutualism
• both organisms benefit
Commensalism
• One is helped, the other is neither harmed
nor helped.
• rare