Agenda 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 livesExample: 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_chainreaction.cfm

http://www.youtube.com/watch?v=D1aRSeT-mQE

• This disrupts the flow of energy from the sun to the organisms