1. Interactions Between Organisms

2. Symbiosis  Symbiosis occurs when two species live closely together in a relationship that lasts over time  If you’ve ever seen documentaries about sharks, you may have noticed other small fish following the shark around. These fish are called remoras and they have an important symbiotic relationship with the shark.

3. Symbiosis  There are three different types of symbiotic relationships

4. 1) Mutualism  In the case of the shark and the remora, the remora uses its suckers to attach itself to the shark, where it feeds on bacteria and micro-organisms. The remora gets a great meal!  The shark benefits because the remora cleans it of potentially unhealthy bacteria and micro-organisms.  Both animals benefit!!!!

5. Mutualism (cont.)  Ants and aphids also have a relationship that is mutualistic. The aphids get protection from the ants and the ants get the sweet liquid the aphids secrete

6. 2) Parasitism  Parasitism is a relationship between two different organisms where one is benefitted and one is harmed.  Typically, one of the organisms live in or on the other and feeds on it.  One of the organisms, the parasite, meets its needs at the expense of the other organism, the host.

7. Parasitism  A beef tapeworm inside a human can grow up to 25 feet long!!! The tapeworm would live in the intestine and eat nutrients that were meant for the human. Gross!!!

8. 3) Commensalism  Commensalism is a relationship between two different organisms where one benefits and the other appears neither to lose or gain from the relationship

9. Commensalism  Many species of flowering orchids live high up, attached to the trunks of trees. The orchids benefit by having a safe place to live with a constant source of water, but the tree doesn’t seem to benefit or lose from the presence of the orchid.

10. Thoughts???  Can you come up with any more symbiotic relationships? - either mutualism, parasitism or commensalism…

11. Thoughts???  gut fauna in herbivores  coral organisms and algae  land plants & the land ecosystem  clownfish and sea anemones  spiders building webs on plants  fleas on pets  ticks or lice on humans

12. Activity  get a partner  take a slip of paper from the teacher and follow the instructions  complete the activity  be back by the end of class