Science.6.12.B

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The student is expected to describe and give examples of predatory, competitive, and symbiotic relationships between organisms, including mutualism, parasitism, and commensalism; and
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Knowledge and Skills Statement

Organisms and environments. The student knows that interdependence occurs between living systems and the environment.

The impact of the relationship on each organism must be identified in order to recognize the form of symbiosis that exists between two organisms.

An example of mutualism is the formation of lichen. Lichen is a partnership of fungus and algae. The fungus benefits from the relationship because it receives nutrition from the photosynthetic algae. The algae benefit from the fungus because the fungus is the organism in the partnership that grows and spreads, providing more space for the algae to grow as well.

Yellow lichen

User Hedning on sv.wikipedia, Public domain, via Wikimedia Commons

An example of commensalism is the relationship between egrets and cattle. The egrets eat the flies and bugs that get stirred up as the cattle graze, however the cattle do not benefit from the egret. 

Cattle Egret standing on the back of cattle

Dr. Raju Kasambe, CC BY-SA 4.0 <https://creativecommons.org/licenses/by-sa/4.0>, via Wikimedia Commons

There are several types of parasitism. One type is brood parasitism. Most species of cuckoos and all cowbirds engage in brood parasitism. The cuckoos and cowbirds do not build their own nests. Instead, they place their eggs in the nests of other species and leave them there for the nest builders to care for. 

An Eastern Phoebe (Sayornis phoebe) nest containing five Phoebe eggs and one Brown-headed Cowbird (Molothrus ater) egg

Galawebdesign, CC BY 3.0 <https://creativecommons.org/licenses/by/3.0>, via Wikimedia Commons 

a type of symbiotic relationship between two organisms where one organism benefits and the other is not harmed

a relationship between two organisms where they vie for specific resources

the circumstances, objects, or conditions that surround an organism including abiotic (climate and soil) and biotic (living organisms) that act upon an organism or an ecological community and ultimately determine its form and survival

the state of being dependent upon one another; a mutually dependent relationship

a type of symbiotic relationship between two organisms where both benefit from the association

an individual form of life, such as a plant, animal, bacterium, protist, or fungus; a body made up of organs, organelles, or other parts that work together to carry on the various processes of life

a type of symbiotic relationship between two organisms where one benefits by taking food, energy, or shelter and harming the other

a type of relationship between two organisms where one (the predator) consumes the other (the prey) as food

relationships between organisms where both organisms survive and at least one benefits from the association; includes mutualism, commensalism, and parasitism

Research

Lord, Joshua. “Science Shorts: How Symbiosis Creates Diversity.” Science and Children 47, no. 5 (January 2010): 64–66. http://www.jstor.org/stable/43174709.

Summary: How Symbiosis Creates Diversity explains a variety of ways two organisms may interact in which at least one benefits from the other.  An example 5E lesson is shared along with extension ideas.