Symbiotic Relationships
The relationship betwwen two dissimilar organisms living together. There are many different types of symbiotic relationships. There is mutualism, commensalism, amensalism, or parasitism.

Mutualism
A relationship between two different species of organisms in which both benefit from the association. Ex: Humans get O2 from plants and cultivated plants get CO2 from humans, humans and intestinal bacteria, and flowering plants get pollinated by bees and pollinators get free pollen. Picture of a pollinater polllinating flowers is on http://www.fs.fed.us/wildflowers/pollinators/images/pollinators.jpg

Commensalism
A relationship between two different species of organisms in which one derives some benefit while the other is unaffected. Ex: Barnacles adhering to the skin of a whale to hitch a free ride and to filter-feed off the water around the whale, remora sucking on to get leftover food from the sharks, and orchids in trees. Picture of barnicles on a whale is on ****http://www.freenaturepictures.com/assets/images/hires/whaleblowing.jpg**** and picture of remora on a shark is on http://www.dkimages.com/discover/previews/755/267892.JPG

Amensalism
A relationship between two different organisms in which one species is harmed or inhibited and the other species is unaffected. Ex: Penicillium kills bacteria, and the black walnut tree that harms or kills some species of neighboring plants. Picture of penicilluim killing bacteria is on http://botit.botany.wisc.edu/toms_fungi/images/pen1.jpg

Parasitism
A relationship in which one organism, which is the parasite, benefits and the other, which is the host, is generally harmed. Ex: Heartworms in dogs and misquitoes sucking on humans. Picture of a mosquito sucking blood out of a human is on ****http://www.esa.int/images/itesa1_5907194_MEQ_mosquito_L.jpg****