Student Science Journal
6.4.3
Food Webs
Name ____________________
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Episode 1
The Cycling of Matter in an Ecosystem
Matter is made of tiny particles that make up everything — living and nonliving. In an ecosystem, matter moves in a cycle. It starts in nonliving parts of the environment, moves through living things, and then returns back to nonliving things.
It all begins with the nonliving environment. Water, carbon dioxide, and nutrients in the soil are examples of nonliving matter. These materials are taken in by producers, like plants. Producers use sunlight to rearrange particles in water and carbon dioxide into energy and plant matter through a process called photosynthesis. Producers also take in nutrients from the soil. The matter from the nonliving world becomes part of the plant’s body.
When an animal eats a plant, some of that matter moves into that animal (called a consumer). Consumers can be herbivores (plant-eaters), carnivores (meat-eaters), or omnivores (eat both). These animals use the matter from their food to build their own bodies and get energy to live and grow.
When plants and animals die, or when animals produce waste, decomposers like fungi, bacteria, and worms get to work. They break down the dead material into smaller parts. This releases nutrients back into the soil and carbon dioxide into the air.
Now, the matter is back in the nonliving environment — and the cycle begins again.
Matter moves from nonliving things to plants, then to animals, then to decomposers, and back to nonliving things. The cycle keeps going so living things can survive.
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Episode 1: The Cycling of Matter in an Ecosystem
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6.4.3
Develop a model to describe how matter cycles through an ecosystem.
Include the following components: | | ||
primary | water | secondary | nutrients |
consumers | matter | carbon dioxide | producers |
cycle | decomposers | non-living environment | |
Episode 2 - The Flow of Energy in an Ecosystem
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6.4.3
Matter and Energy in an Ecosystem
In every ecosystem, energy and matter move between living and nonliving parts. They work together to keep life going, but they move in different ways.
Matter cycles through an ecosystem. Matter includes plant and animal matter, water, oxygen, carbon dioxide, and nutrients like nitrogen. These materials move through producers (plants), consumers (animals), and decomposers. When living things die or produce waste, decomposers break matter down and return the nutrients to the soil and release carbon dioxide into the air. Then plants take this matter in again, and the cycle continues. Matter is reused over and over again.
Energy flows through an ecosystem, starting with the sun. During photosynthesis, plants capture sunlight and use it to power a chemical reaction that rearranges water and carbon dioxide molecules to form glucose. Glucose is a type of sugar that makes up much of a plant’s structure. The energy from the sun is stored in the chemical bonds of the glucose molecules.
Animals use energy from food to build bones, muscles, and other body parts from the matter they eat. This rearranged matter becomes part of the next organism in the food web.
Together, the flow of energy and the cycling of matter help keep ecosystems in balance.
When animals eat plants, they take in the stored energy from glucose. Inside their bodies, they break the chemical bonds in glucose to release that energy. This process, called cellular respiration, gives animals the energy they need to move, grow, breathe, and think. The energy flow continues when animals eat other animals. But at each step, some energy is used by the organism or lost to the environment as heat. Because of this, energy cannot be recycled — once it’s used, it’s gone. That’s why ecosystems always need a constant supply of new energy from the sun.
Episode 2 - The Flow of Energy in an Ecosystem
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6.4.3
Use your model to explain how energy flows through an ecosystem.
Episode 3 - Energy and Matter in an Ecosystem
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6.4.3
Include the following organisms: skunk fox | ||||
owl | mouse | acorn | grass | grasshopper |
hawk | opossum | weasel | bacteria | |
What other components should be included in your model?: | |||
| | | |
Develop a model showing flow of matter and cycling of energy in an ecosystem..
Episode 4 - Great Salt Lake Food Webs
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1. Visit the following website: http://learn.genetics.utah.edu/content/gsl/foodweb/
2. Read the introductory paragraph.
3. Click on the information link for birds.
4. Click on the information link for brine flies.
5. Click on the information link for bottom-dwelling microbes.
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Type of Organism | Explanation |
Producers | |
Primary Consumers | |
Secondary Consumers | |
6. Click on the information link for brine shrimp.
7. Click on the information link for free-floating microbes.
8. Study the diagram of the food web and place each organism into the correct category in the table below. Explain how the organisms fit into that category.
9. Read the section on how energy is transferred up the food pyramid.
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10. Draw a food web using the following organisms that live in the Great Salt Lake. Label the food web with explanations of how each organism receives and transfers energy and matter.
BRINE SHRIMP BRINE FLIES SNOWY PLOVER CYANOBACTERIA
COYOTE PLANKTON PEREGRINE FALCON WILSON’S PHALAROPE
11. What role do decomposers play in the food web above?
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RESOURCES
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6.4.3
Episode 1 Resource 1 of 5
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Decomposer
Producers use sunlight to make their own matter by rearranging particles from water and the air. Producers don’t need to eat other organisms to grow, but they do use trace nutrients from soil.
Secondary Consumer
Primary Consumer
Producer
Decomposers break down dead producers and consumers. Decomposers release mostly carbon dioxide and trace amounts of nutrients to be reused by producers. Includes worms, mushrooms, bacteria, fungi and some insects.
Primary consumers, or herbivores, eat producers to get the matter and nutrients their bodies need to grow and survive.
Secondary consumers get their matter and nutrients by eating other consumers. They are called carnivores or meat eaters. Omnivores are a type of secondary consumer that will eat both plants and other animals.
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Episode 1 Resource page 2 of 5
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Episode 1 Resource page 3 of 5
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Episode 1 Resource page 4 of 5
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Episode 1 Resource page 5 of 5
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Set One Cards
carbon dioxide
caterpillar
robin
leaf
snake
raccoon
6.4.3
water
mushroom
Episode 3 Resource page 1 of 3
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Set Two Cards
hawk
grass
grasshopper
acorn
opossum
weasel
skunk
fox
mouse
owl
6.4.3
Episode 3 Resource page 2 of 3
bacteria
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Organism | What it Eats |
Mouse | Seeds, nuts, grains, fruits, insects, grass |
Grasshopper | Grass, leaves, flowers, stems |
Opossum | Insects, rodents, fruits, eggs, grains |
Weasel | Mice, voles, rabbits, small birds, frogs, insects, eggs |
Skunk | Insects, rodents, fruits, berries, eggs, amphibians, and reptiles |
Fox | Mice, rabbits, birds, insects, fruits and berries, frogs and small reptiles |
Owl | Rodents, rabbits, small birds, insects, sometimes amphibians |
Hawk | Mice, rabbits, squirrels, snakes, birds, frogs, young or injured foxes |
Set Two
additional information
Episode 3 Resource page 3 of 3