A particular species of a unicellular organism inhabits the intestines of termites, where the unicellular organisms are protected from predators. Wood that is ingested by the termites is digested by the unicellular organisms, forming food for the

1
A particular species of a unicellular organism
inhabits the intestines of termites, where the
unicellular organisms are protected from
predators. Wood that is ingested by the termites
is digested by the unicellular organisms, forming
food for the termites.

• Mutualism

2
Mistletoe grows on trees. It sends its roots
into the tree and uses the nutrients that could
otherwise be used by the tree. Therefore, the
tree does not get to use all the nutrients and
usually dies.

• Parasitism

3
Lichen species are made up of a fungus that
contains either a bacterium or an alga. The
fungus protects the bacterium or alga, and the
bacterium or alga provides food for the fungus.

• Mutualism

4
An American Robin benefits by building its nest
in a Red Maple tree. The tree is unaffected.

• Commensalism

5
Some ant species use excess plant sap for their
own nutrition. These ants will find a colony of
aphids and milk the waste plant sap from the
cornicles. In return the ants protect the aphids
from predators and parasites.

• Mutualism

6
Barnacles live by using long, feathering
appendages to sweep the surrounding water for
small, free-floating organisms. The critical
resource for barnacles is a place to stay.
Barnacles attach to rocks, ships, shells, whales,
and just about anywhere else they can gain a
foothold.

• Commensalism

7
The honey bee gets to eat the pollen from the
flower. The dandelion uses the bee to spread its
pollen to another flower.

• Mutualism

8
The tick gets food from the deer without killing
it. The deer is harmed by losing blood to the
tick, and possibly by getting an infected wound.

• Parasitism

9
Birds and mammals eat berries and fruit off of
plants in the wild. The birds and mammals derive
a food benefit by eating the berries and fruits.
The plant, in turn, disperses it seeds.

• Mutualism

10
Many species of moss or algae may live on the
bark of a tree. The tree is completely unaffected
and the moss or algae has a place to live.

• Commensalism

11
Female mosquitoes ingest blood from humans and
mammals for the protein to feed their larva. The
saliva of the mosquito causes the skin to become
irritated and itchy.

• Parasitism

12
Oxpeckers land on rhinos or zebras and eat ticks
and other parasites that live on their skin. The
oxpeckers get food and the beasts get pest
control.

• Mutualism

13
A few species of pseudo-scorpions disperse by
concealing themselves under the wing covers of
large beetles. The pseudo-scorpions gain the
advantage of being dispersed over wide areas
while simultaneously being protected from
predators. The beetle is, presumably, unaffected
by the presence of the hitchhikers.

• Commensalism

14
Hookworms infect humans by residing in the small
intestine and feeds off of the digested food in
the small intestines. As the hookworm grows
larger, the human slowly starves to death.

• Parasitism