Unit 3: Ecological Interactions

Why Can’t We All Just Get Along?

Objective:  To explain the types of relationships that exist between organisms

Bell work:  Define the following terms in your own words:

• Competition:

To fight for a resource

• Predator:

The organism that hunts

• Prey:

The organism that gets eaten

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Predation: interaction where one organism (predator) kills another organism for food (prey)

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Competition: struggle between organisms to survive as they attempt to use the same limited resource

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Limiting Factors of Ecosystems

Limiting factor: an environmental condition or resource that limits the size of a population of organisms.

What are examples

of limiting factors?

-Food

-Water

-Weather

-Accidents

-Natural Catastrophe

-Disease

-Predators

-Space/Habitat

-Mate

-Competition

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The largest population an area can support is its carrying capacity which is driven by limiting factors.

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Interactions of Living Things

Symbiosis: close relationship created between two species due to coevolution (species evolve together in their environment).

The relationship must benefit at least one of the species.

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OR

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There are three types of symbiotic relationships:

Mutualism (+,+): relationship where both species benefit

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Commensalism (+,0): relationship where one species benefits and the other species is neither helped nor harmed

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Parasitism (+,-): relationship where one species benefits (parasite) while the other is harmed (host)

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Wanted: Symbiotic Relationship�Apply Within!

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What You Do:

Create a classified advertisement/want ad for a job opening in which an organism in a symbiotic relationship is looking for the other organism. The ad should be based on a mutualistic, parasitic, or commensalistic relationship.

Headline describing job

Create a catchy headline to grab attention. Write a line describing the relationship you are seeking (mutualistic, parasitic, commensalistic), a line about who you are and the qualities you possess, a line about the type of organism you need for the job (Qualifications), a line about why you need this service, and a line describing what you will give the organism in return for his or her services.

Picture accompanying advertisement:

A picture showing you, the organism in search of the other organism. A picture showing the organism of which you are searching. A picture showing the two of you together in your symbiotic relationship - can be hand-drawn. Must be neat and colorful

Materials to use

To create this ad, use construction paper, copy paper, magazine/newspaper cutouts, clip art, computer graphics, photographs, hand drawn images, etc.

The ad can be done as a PowerPoint presentation, brochure, newspaper ad, magazine ad, poster, prezi presentation, glogster, etc.

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WANTED: Lazy Pup with Short Nails

Desperately seeking a parasitic relationship. I am a flea with a thin body and springy legs who can jump 1,000 times my own body size! I am in search of a dog with long fur for me to cuddle up in, thin skin for me to bite, and short nails to keep from scratching me. I need your help because your blood is my nutrients and I need it to keep me alive. In return, I promise to give you the heebie jeebies and plenty of scabby bites to scratch and keep you busy!

ME YOU US TOGETHER

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Listed below are several symbiotic relationships. Once you have been assigned your relationship, write the pair of organisms at the top of your paper. Research your relationship and follow all directions to complete your Want Ad.

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Analyzing Predator-Prey Relationships

Background:

The Midwest Grey Wolf has been taken off of the Endangered species list due to their numbers increasing. The resurgence began in northeast Minnesota and their populations have increased as the wolves move into territories that foster support for their steady growth. In Idaho, the wolf populations have had a great gain in population size due to an abundant food supply - Elk. The Fish and Game Department released the Lolo Elk counts for Wildlife Management Zones 10 and 12 and has detailed the data in the charts below.  

Objective:

To analyze data demonstrating the effects of organism interactions on population size.

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What You Do: Using the information provided in the charts below, analyze the data and answer the questions that follow.

The population change is the number of elk born minus the number of elk that died during that year. Fill out the last column for the year each year using the calculation below - Be sure to show if the change is positive or negative:

Elk calves – (Predation + Starvation) = Elk population change

For the year 2000: 800 – (400 + 100) = 300

An increase in elk population from the previous year.

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Check Your Answers!

Elk calves – (Predation + Starvation) = Elk population change

Be sure to show if the change is positive or negative

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Analyzing Predator-Prey Relationships

The Results – What Happened?

Graph your data by creating a DOUBLE LINE graph of the data from the chart on the previous page. Analyze the results and answer the questions that follow.

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STOP HERE FOR THE DAY!