This document summarizes different types of biotic relationships: 1) Predator-prey relationships involve one organism preying upon another for food. Examples given are eagles preying on rabbits and cheetahs preying on zebras. 2) Mutualism involves a positive reciprocal relationship that benefits both species, such as Egyptian plovers cleaning crocodile teeth and clownfish protecting anemones from parasites. 3) Commensalism benefits one species without affecting the other, like egrets feeding on insects stirred up by cattle. 4) Parasitism benefits one species at the expense of the other, for example wasp larvae developing inside caterpill

1. FBiotic Relationships c
by Niklaus Teo, See To, Tim Yap, Jia Le,
Johanan Teo

2. Predator-Prey AG
Definition of Predator-Prey Relationship:
— The interaction of two organisms in which one of them is the
predator and captures/feeds on the other organism know as the
prey.
— Predation can be also know as population control seen in the
right image
— It can be presented simply in the form of food chain/web.
Graph Showing Population Control By The
Predator - Prey Relationship
Examples :
1) Eagle (Predator) & Rabbit (Prey)
Red Fox
(Predator)
Feeding On A
2)Cheetah (Predator) & Zebra (Prey) Hare (Prey), taken
from http://
www.personal.ps
u.edu/euw122/
PHYS_527/
HWK_2/pic.jpg
Done by Johanan, information taken from http://www.globalchange.umich.edu/globalchange1/current/lectures/predation/predation.html

3. Mutualism l
f
Definition of Mutualism:
— Positive reciprocal relationship between two species for survival
— Reasons - Food, shelter, defense, transport, pollination, nutrition etc.
— Types - Symbiotic relationship (obligate relationship), Non-symbiotic
(in time of need)
Examples:
The crocodile lets the plover clean its
teeth.
1) The Egyptian plover removes and eats meat stuck in
between the crocodile’s teeth and feeds parasites off its tongue,
getting a meal from the crocodile and giving it a dental cleanup. Clownfish are covered with slimy
mucus that protects them from the
anemone.
2) Clown fish get protection by dwelling in the Ritteri sea
anemones and in return cleans food leftovers and keeps the
anemone well circulated by fanning their fins.
Done by Jia Le, information taken from http://www.pz.harvard.edu/ucp/curriculum/
ecosystems/s5_res_symbiosis.pdf , http://tolweb.org/treehouses/?
treehouse_id=3390

4. Commensalism
Definition of Commensalism:
— One organism benefits but the other is neutral (there is no harm or benefit)
— The two animals are called commensals.
— Commensalism is a type of symbiosis.
The Remora shark is hitching a ride on
Examples: another shark as seen in the picture. This is
an example of commensalism(http://
thelostjacket.com/community/parasitic-
marketing
1)While feeding, cattle kick up insects, which the egrets quickly
eat. The birds get a good meal, but the cattle receive no benefit
or harm.
The Egrets are standing on the cattle while it
waits for their chance to feed on insects (http://
2)Remora sharks are endowed with an adhesive disk on the dorsal www.game-reserve.com/)
surface of their heads. They use this adhesive disk to “hitch a
ride” on larger animals, usually whales, which tend to be sloppy
eaters. When food floats away from the whale’s mouth, the
remora can unhitch itself and collect the scraps of food floating
by.
Done by Niklaus, information taken from http://www.nearctica.com/ecology/pops/commens.htm
http://www.cbu.edu/~seisen/ExamplesOfCommensalism.htm

5. Definition of Parasitism:
Parasitism
—The parasite benefits while the host suffers.
—Organism that lives on or within another organism>> Within the host :Endoparasites
Outside the host : Ectoparasites
—Organisms that live by drawing food from a host organism
—Parasitosis refers forms of parasitism that injure the host
Image to the left shows the flea, a
common parasite among animals like
Examples: cats and dogs http://
1) A type of parasitic wasp lays its eggs in another host insect, commonly a static.howstuffworks.com/gif/flea-1.jpg
caterpillar
2) Tapeworms may also invade dogs or cats if they accidentally swallow
fleas during grooming
3) Lamprey, a type of parasitic fish, sucks the blood of other fishes
4)When a human eats undercooked meat or fish, they may get invaded by
tapeworms, which robs the human of the vitamin B12. Its excrement is also
toxic and might be harmful Image left shows a possible way of
-Human parasites :Hookworm, Tapeworm, Heartworm, Roundworm how parasites get into the human
body http://altered-states.net/barry/
update200/parasite_chart.gif
Done by See To, information taken from http://kids.britannica.com/comptons/article-206156/parasite

6. Symbiosis among Plants
An example of symbiosis among plants is the Mistletoe.
It performs a symbiotic relationship with trees (almost any deciduous type) in
which the mistletoe is the parasite and the tree is the host.
In this picture, the mistletoe is shown growing
on a tree branch. Anyone want to kiss under it?
Taken from http://www.treeweaverarborist.com/
How the mistletoe does it:
blog/?p=65
— One of the familiar sticky berries of the mistletoe comes
into contact with the bark of a tree - generally through the
agency of birds.
— After a few days it sends forth a thread-like root,
flattened at the extremity like the proboscis of a fly.
— This pierces the bark and roots itself firmly in the
growing wood, from which it has the power of selecting and
appropriating to its own use, such juices as are fitted for its
sustenance.
—The mistletoe at no period derives nourishment from the
soil, or from decayed bark, like some of the fungi do - all its
nourishment is obtained from its host. The root becomes
Done by Tim, information taken from http://botanical.com/botanical/mgmh/m/mistle40.html woody and thick.

7. The End
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