This document discusses three types of relationships between organisms: 1) Mutualism, where two organisms benefit each other, such as butterflies and flowers where the butterfly gets nectar and pollinates flowers. 2) Commensalism, where one organism benefits without affecting the other, like remoras eating scraps from sharks or orchids growing on trees. 3) Parasitism, where one organism harms the host to benefit itself, as in the case of aphids sucking the juices of roses.

1. RELATIONSHIPS AMONG ORGANISMS
1.Mutualism – this is a relationship
where two organisms live together in a
common space so that each organism
will benefit. For example: the butterfly
and flowers.
Butterfly hovers around the
flowering plants because it is attracted
by the color and odor of the flowers. It
also sips nectars from the flowers.

2. The flowers on the other hand,
benefit from it because as the
butterfly hovers from one flower to
another, it transfer pollen grains and
pollinates the flowers. The flowers are
able to reproduce because the insect
carries pollen from flower to flower.
Termites and one –celled organisms
from a termite intestine also show
mutualism.

5. The bird cleans the teeth of the crocodile. It picks out
small pieces of meat. In return for this service, the
crocodile does not harm the bird. There is a free cleaning
for the crocodile and a free meal for the bird. Both
animals depend upon each other.

6. 2. Commensalism – is a kind of relationship by
which only one organism benefits. The other
is not harmed nor affected at all. Commensal
is the one that receives the benefit. The host
is the partner that is neither benefited nor
harmed. An example of commensalism is the
relationship between a shark and a remora.
Remora, a sucker fish, attaches itself to the
underside of the body of the shark. As the
shark feeds, the remora picks up the scraps of
food which the shark leaves.

8. Another example is an aerial plant
or epiphytes growing on the branches
of a tree. Orchids cling onto the
branches of trees. Their presence does
not affect the tree although the tree
provides support and place for the
orchids to grow. The orchids does not
affect the tree because they can
manufacture their own food through
photosynthesis.

10. The relationship between the clownfish and
the anemone is another example of
commensalism. The sea anemone may look
like a plant but it is actually an underwater
animal. The long tube like “leaves” are in
fact tentacles with stinging cells that project
poisonous threads. The sea anemone feeds
by stinging prey with its tentacles. The
clownfish can swim without fear into the
tentacles with open arms of the sea
anemone because it has a protective layer of
liquid on its body.

11. The clownfish seek shelter with the sea
anemone’s tentacles and gain protection from its
enemies. It also picks up left over food from the
sea anemone. The sea anemone gets nothing from
the relationship.

12. 3. Parasitism – is a kind of relationship where
one organism benefits and the other is badly
affected. The organism that benefits is the
parasite. The organism that is harmed is the
host. Parasites cannot live alone. They must
live on a living host.
Example: Aphids and a rose show parasitism.
An aphid is a louse that lives on plants and
sucks their juices. Aphids are insect parasite.
They are tiny white cotton-like spots
underneath the leaves of roses.

14. Other example of parasite-host
relationships are a flea and a dog.

15. Other example of parasite-host
relationship is head lice on a child’s
hair.

16. Parasites that live outside the body of the host is
called ectoparasites.
Examples: lice, fleas, and ticks

17. Parasites that live inside the body
of their host are called endoparasites.
Examples : hookworms and tapeworms