Symbiotic Relationships Different organisms live together in a

Symbiotic Relationships Ø Different organisms live together in a close association (symbiosis) which may include: nutritional, reproductive, and protective relationships.

Ø Symbiotic relationships may or may not be beneficial to the organisms involved.

Types of symbiosis include:

Commensalism One organism is benefited and the other is not affected (+, 0).

Gray Whale with Barnacles

Orchids on large tropical trees

Commensalism http: //www. youtube. com/watch? v=e 4 xrdea gy. YM http: //www. youtube. com/watch? v=48 e. KFw 7 DDb. Y&feature=related

Remora fish and shark

Mutualism. In this relationship both organisms benefit from the association (+, +).

Mutualism http: //www. youtube. com/watch? v=8 BEKrca. XF 8&feature=related http: //www. youtube. com/watch? v=z 3 b. Wql. PLp. Mg http: //www. youtube. com/watch? v=c 5 W 3 e. S 1 Zdx. A&feature =related http: //www. youtube. com/watch? v=Af 12 s. Xa 5 -oo&feature=related

Nitrogen‑fixing bacteria within the nodules (roots) of legumes

Protozoa within Termites

A Flower and Bee

Parasitism The parasite benefits at the expense of the host (+, -).

Parasites http: //www. youtube. com/watch? v=pw 7 TSYLRrm. Q Elephantiasis http: //www. youtube. com/watch? v=tbw. DJLPi. MXE Elephantiasis http: //www. youtube. com/watch? v=Mg. Hl. DHw. NH 2 Q scrotum http: //www. youtube. com/watch? v=EXuo. OWb 8 b. Gg&feature=related worm http: //www. youtube. com/watch? v=23 eim. VLAQ 2 c Bot fly

Athlete's foot fungus

Tapeworm, heartworm and fleas in dogs

Competition occurs when different organisms living in the same environment (habitat) utilize the same limited resources – food, space, water, light, oxygen and minerals.

Buffalo, croc, lion awesome! http: //www. youtube. com/watch? v=LU 8 DDYz 68 k. M

Ø The more similar the requirements of the organisms involved, the more intense the competition. Ø This competition between different species is called interspecies competition.

A niche is the role that a species plays in its environment.

Ø If two different species compete for the same food or reproductive sites, one species may be eliminated. Ø This usually establishes one species per niche in a community.

Ex) bluebird and starling compete for a reproductive site - the starling usually “wins, ” causing the bluebird to be pushed out of that community.

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