1. Symbiotic Relationships

2. Symbiosis
An interaction between two different organisms living in a close, physical association
3 Types of Symbiotic Relationships:
1. Mutualism (win/ win)
2. Commensalism (win/ no win or lose)
3. Parasitism (win/ lose)

3. Mutualism
BOTH organisms BENEFIT from the interaction (the “good” is “mutual”)
Examples:
Three-toed sloths and green algae: Algae live in the
fur of the sloth and provide camouflage for the sloth.
The algae get more sunlight (sloths live in tall trees).
Both organisms BENEFIT!
Zebras and oxpeckers: Oxpeckers are birds that
land on the backs of zebras (and rhinos). They
pick ticks off of them. The birds get food and the
zebras get rid of pests. Both organisms BENEFIT!

4. Commensalism
One of the organisms benefits and the other is neither harmed nor helped.
Examples:
Clown fish and sea anemones: Clown fish live in
sea anemones. The clown fish get protection,
and the sea anemone is neither hurt or helped.
Epiphytes and trees: Epiphytes are plants that grow
on the bark of trees. The epiphytes get nutrients
from the air and get extra sunlight by growing on
taller trees in the forest. The trees are not helped
or harmed by this.

5. Parasitism
One organism (the parasite) benefits, and the other organism (the host) is harmed.
Usually the parasite gets nutrients/ food at the expense of the host organism (causing it to become ill and often times transmitting diseases too)
Examples:
Tapeworms: Tapeworms live in the intestines of
some animals. The tapeworms get nutrients from
their host, and the host animal becomes very sick,
as they are not getting enough nutrients of their own.
Ticks: Ticks live on the skin/ in the fur of some animals.
The ticks bite the animals and eat their
blood for food. Ticks also carry and
transmit lyme disease (flu-like).