Food Chains A look at how organisms obtain the energy necessary for life.
How to use the tutorial To find your way through this tutorial, simply use your mouse to click on the buttons at the bottom of the screen to perform the following actions: To return to the beginning of the tutorial, click on the Home button. To return to the previous page, click the back arrow button. To move to the next page, click the next arrow button. Goals After complete of this tutorial the learner will be able to: -list the categories of organisms within an ecosystem -analyze the transfer of energy in the animal kingdom. categorize organism from their park as producers, consumers, scavengers, or decomposers. Instructions Complete this tutorial by using your mouse to navigate.
How do we get energy? Every action we do uses up energy! If we run, jump, sit, oreven sleep, that activity requires energy. So how do we get all this energy? This tutorial will help us to answer that question. In science, we look at how organisms obtain energy throw what is called a food chain. A food chain is a visual representation of how energy flows through an ecosystem. This tutorial will cover where energy comes from and how it flows through the living creatures around us. This tutorial will look at specific organisms and energy transfer with respect to Yellowstone National park. My tutorial will examine the organisms of this park. The first part of understanding a food chain is to know the categories of organisms. The tutorial will begin by defining the categories and giving examples from the park. There are 4 categories that an organism can fall into: producers, consumers, scavengers, and decomposers. Each one will be described in the following slides. Picture taken from Yellowstone National Park
What is a Producer? Google says that a producer is ”a person or thing that makes or causes something.” (Google Definition) If we take that definition and combine it to the idea of energy transfer between organisms, then we would assume that a producer is an organism that produces energy. By producing energy, they would be at the bottom of the food chain. They are the source of all energy in an ecosystem. These organisms make energy by converting it from sunlight. This process is called photosynthesis. Through photosynthesis, plants take sunlight, water, carbon dioxide, and other minerals and turn them into oxygen and glucose. Glucose is a sugar. It is because of this sugar that all other organisms survive. All organisms use glucose for energy, and it all starts with the producers. All energy flow starts with these organisms. Sheppardsoftware.com Photosynthesis
More on Producers Producers make up the first and bottom level of the food chain. Because they can make their own energy, they do not need to consume other living organisms. As long as there is sun, water, and soil you will get some form of producer. Not only do these organism produce necessary food for other organism, but they also produce oxygen through photosynthesis. Most organisms also need oxygen to survive. The producers really are our foundation of life. With out them, we wouldn’t be able to breathe, let alone eat. Next time you see a field of wild flowers, stop to admire the beauty as well as the life sustaining substance that these beautiful flowers afford us. This is an example of a wild flower that can be found in Yellowstone National Park. Flowers like these are the essential to life in the park. They produce pollen that feeds the insects that so many of the other animals eat to survive. Wildflowerswest.org
What is a Consumer? Google says that a consumer is “an organism of an ecological food chain that receive their energy by consuming other organisms.” Google Definition This definition tells us flat out that a consumer must “consume” or eat, drink, or ingest other organism to obtain energy. They cannot make their own energy so they must eat to get it. Consumers make up the next levels of the food chain. Geography4kids tells us that this category can be broken into 3 different sub categories; herbivore, carnivore, and omnivore. A herbivore (primary consumer) gets all of its energy from eating producers, or plants. A carnivore (secondary consumer) gets all of its energy by consuming other smaller consumers. And an omnivore gets its energy by consuming both producers and other consumers. Picture taken from: http://moodleshare.org/mod/book/view.php?id=1747&chapterid=221
More on Consumers The scary thing about being a consumer is that in this group you may think you get to eat other organism, but you better watch out because there will always be something that wants to eat you too. This is where a food chain expands to become a more complicated food web. Many organisms eat and are eaten by many other organisms. An ecosystem can look pretty confusing when you start to look at the energy flow through its organisms. While we don’t tend to think of humans as animals, we must consume to get our energy too. We fall under this second level, the consumer level. Specifically we fall under the omnivore subcategory because we eat fruits and vegetables (producers) as well as chickens and other animals (other consumers). Picture from: http://doyoudothatathome.com/2010/06/23/yellowstone-national-park-part-iii/
What is a Decomposer? Decomposers are essential to the ecosystem. They break down dead plants and animals. They are like the recycling team of the ecosystem. The decomposer category is actually broken down into two subcategories; scavenger and decomposer. There is some controversy over which category to put scavengers in. It consumes dead meat so some want to add it to he consumer sub categories. It is also cleaning up waste, which make some want to add it to the decomposer subcategories. For this tutorial, we will add it to the decomposer subcategory because the job of cleaning up leftovers is extremely important and we are thankful enough to add them to the recycling team. Picturefrom: http://www.fadingad.com/fadingadblog/?p=1125
What is a Decomposer? National Geographic Education defines a scavenger as an “organism that consumes decaying meat.” In and ecosystem, this would mean that the scavenger finds a dead animal laying in the park and uses that as a meal. A scavenger makes up the first line of defense from the world filling up with dead animals. A scavenger does not hunt down other organisms for its food. It waits until another animal does that, finishes eating, and then goes in to have the left overs. It may sound gross but it would be a lot more gross to live in a world full of left over meals. In Yellowstone, ravens and coyotes are examples of some scavengers. Picture from: http://www.superstock.com/stock-photos-images/4201-36470
More on Decomposers The second subcategory of decomposers is the decomposers. These are fungi (fungus) and bacteria that live all around us. These organisms are responsible for breaking down everything that is not eaten by something else. Consider them the recycling team of Earth. They don’t just get rid of the waste, they break it down into useable minerals and return them to the soil. These organisms may seem ugly and gross, but they serve an incredibly important role in maintaining the ecosystem. Picture from: http://www.superteachertools.com/jeopardyx/jeopardy-review-game.php?gamefile=1320183293
Quick Check This is a quick check. It helps to ensure that you are understanding the tutorial. Answer the following questions and see how you are progressing. If you miss a question you may want to go back a few slides and review the information. • What are the 3 main categories of organisms within an ecosystem? • What are the two subcategories of decomposers? 3) Categorize the following organisms; • Grass • Elk • Bear • Mushroom • Answers: • producer, consumer, and decomposer • scavenger and decomposer • Categorize Grass – producer Elk – consumer, herbivore Bear – consumer, omnivore Mushroom - decomposer
So how does it all work? Energy flow is broken down into levels and those levels are then illustrated in a food chain or a more complex food web. Take a look at this basic food chain. It starts with the grass which is a producer, then energy is transferred to the rabbit when it eats the grass and then to the fox when it eats the rabbit. If we look at the second food chain we see that is still follows the same rules it just incorporates more organisms. The producers uses sun light to make glucose, the grasshopper eats the grass, the shrew eats the grasshopper, and the owl eats the shrew. But a food chain is just the basics. We mentioned earlier that the consumer level is vast and complex. In order to see that, we need to look at a food web. Picture from: SheppardsoftwareKidscorner Picture from: http://www.field-studies-council.org/urbaneco/urbaneco/introduction/feeding.htm
Let’s create our own! For this activity I will list animals that live in my park and which category of organism they are in. Then I want you to envision what the food web might look like. On the next slide, I will show an example of what that food web would look like.
Quick Check Let’s see how you did. Was what you envisioned close to what I created? If not then you may need to review the information in the tutorial. Or you might just need a little more knowledge about the organism included.
A complex food web and explanation If we look at this food web using animals from Yellowstone National Park we can see a clear transfer of energy. The producers are the strawberry plant, sweet cicely root, and the Idaho fescue. These organisms feed the marmot, elk, and grass hopper. The grasshopper feeds the chipmunk. The bear is and omnivore. It exists on various levels food chain. He can be a primary consumer if he eats the strawberry or a secondary consumer if he eats the other animals. Then we can see how everything must at some point die and go to the decomposers. The brackets around every organism and pointing to the decomposers show that every living organism will at some point succumb to the decomposers. They are charged with breaking down everything organism back into the minerals that make it up and returning them to the soil. The minerals are then used up by new producers and it creates a cycle of energy flow with in the ecosystem. Picture from: http://www.doe.mass.edu/mcas/student/2007/question.aspx?GradeID=100&SubjectCode=bio_hs&QuestionTypeName=&QuestionID=5371
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