SYMBIOSIS

How are our relationships comparable to ecology?

Fitting In

• Organisms not only live together in ecological communities, but they also constantly interact with one another. These interactions, which include predation and competition, help shape the ecosystem in which they live.

• 1. Based on your own experiences, define predation. Give one example of predation.

• 2. Based on your own experiences, define competition. Give one example of competition.

Section 4-2

Interest Grabber

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What is symbiosis?• Symbiosis: is a close ecological relationship between the

individuals of two (or more) different species. • Mutualism: cooperative relationship in which both species

derive some benefit.• Example: Pollination

• Parasitism: one individual known as the parasite, feeds on another individual, known as the host.

• Endoparasite- Internal• Ectoparasite- External• Commensalism: interaction in which one species benefits

and the other is not affected.

How do we understand Symbiosis?

• Every ecosystem has many different symbiotic relationships. Each fills a niche. All symbiotic relationships are specific to the organisms. You can’t replace one with another.

Parasites

Commensalism

1. An orchid lives on a tropical tree. It lives on the tree to reach the sunlight.

Mutualism 1. There is a bird, the Egyptian plover, which cleans

crocodile teeth by eating the left over food particles in the crocodile’s mouth.

Biotic Factors

ECOSYSTEM

Abiotic Factors

Section 4-2

Abiotic and Biotic Factors

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Habitat vs. Niche

• Habitat- place where an organism lives

• Niche- the use of its habitat and its function/ role in the community

Niche

• Fundamental niche- the entire range where an organism could survive.

• Realized niche- actual area in a community that an organism occupies due to competition.

Bay-Breasted WarblerFeeds in the middlepart of the tree

Yellow-Rumped WarblerFeeds in the lower part of the tree andat the bases of the middle branches

Cape May WarblerFeeds at the tips of branchesnear the top of the tree

Spruce tree

Section 4-2

Figure 4-5 Three Species of Warblers and Their Niches

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Biomagnification

Movement of toxin through a food chain.

Increases 10x/level

Fish-Eating BirdsMagnification ofDDT Concentration

10,000,000

100,000

10,000

1,000,000

1

1000

LargeFish

Small Fish

Zooplankton

Producers

Water

Section 6-3

Figure 6-16 Biological Magnification of DDT

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