Download Niche: An organism*s role in an ecosystem

Agenda
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5/10
Review of Food Webs
Niche notes
Practice probs
Grades back (remind me at 10-till end)
Learning Target #2
2) I can explain what a niche is and why
ecological relationships are important
CH 15 Notes 2
Niche: An organism’s role in an community
• An organism’s niche includes: What it eats ,
where it lives, how it interacts with other
organisms
• Another way to think about it:
niche = organism’s “job” in its ecosystem
Habitat: The place a species lives
Example: Ant hill
• Ecological relationships: Ways organisms
interact with each other
Different types of ecological
relationships
1. Predation: relationship where one animal
hunts, kills, and eats the other
• Prey: an organism that gets hunted, killed &
eaten
• Predator: an organism that hunts, kills and
eats the other
2. Scavenging: animals feeding off of
other dead animals
Example: Vultures are scavengers that eat road
kill
3. Competition: relationship where two
organisms compete over resources
• Two organisms do not want to have the same
niche.
• If they do, then they compete for resources
(space, food, mates)
4. Symbiotic relationships: Two organisms
of different species closely interact
a. Mutualism: Both organisms benefit  
• Example: bees pollinate flower and get to
drink nectar
b. Commensalism: One organism benefits,
the other is not affected  
• Example: Bird eats insects that an ox disturbs,
the ox isn’t helped or hurt
c. Parasitism: One organism benefits, the
other gets harmed 
• Parasite: an organism that lives on/in another
organism and gets its food from them
• Host: The organism a parasite lives on/in and
feeds from
Why ecological relationships matter:
• If an organism gets removed or added to the
food chain, it affects all the organisms in the
chain!
• This would be like taking a person out of
his/her job OR adding in a new person
http://www.ecokids.ca/pub/eco_info/topics/frogs/chain_reaction/play_chain
reaction.cfm
http://www.youtube.com/watch?v=D1aRSeTmQE
• This disrupts the flow of energy from the sun
to the organisms