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S&S 2.2. Respond to the following question in your lab notebook:

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Presentation on theme: "S&S 2.2. Respond to the following question in your lab notebook:"— Presentation transcript:

1 S&S 2.2

2 Respond to the following question in your lab notebook:

3 I can create a food web that shows the transfer of chemical energy within an ecosystem, and I understand that not all energy makes it to the next level.

4 Food chain- a linear representation of how food is transferred from one organism to another. Food web- A web that shows all of the feeding relationships within an ecosystem. Trophic Level- feeding levels within an ecosystem- the producers are in the first trophic level.

5 Law of Conservation of Energy- Energy cannot be lost because it cannot created or destroyed. Calories- a measure of the amount of energy stored in food.

6 Every organism, dead or alive is a potential source of food for other organisms

7 Used to show how energy is transferred, via food, from producers to primary consumers, from primary to secondary consumers, and so on


9 In nature, many consumers feed on both producers and other consumers, because of this, a Food Chain may not adequately describe all the pathways of energy transfer.

10 A diagram that illustrates the transfer of chemical energy within an ecosystem



13 Based upon its position in the Food Web, each member of an ecosystem can be assigned to a Trophic Level

14 Producers [plants and plankton]

15 Primary Consumers [usually herbivores]

16 Secondary and tertiary consumers [carnivores and omnivores]

17 Whenever one organism eats another, chemical energy is transferred to a higher trophic level Some energy is not used by the consumer; some is transformed into heat, some remains in the food not eaten The amount of energy stored in food is measured in CALORIES


19 Draw a Food Web, showing energy transfer among: TroutGulls HumansCatfish MinnowsBacteria InsectsPhytoplankton Herbivorous zooplankton Carnivorous zooplankton

20 1. Rank the organisms in your Food Web from most abundant in the ecosystem to least abundant in the ecosystem. Explain how you determined your rankings.

21 2. When 1 organism eats another, not all of the energy stored in the food gets transferred to the consumer. What happens to the energy that is lost during each transfer?

22 3. In 1 m 3 of a typical open ocean ecosystem, phytoplankton can generate 1,600,000 Calories of chemical energy per year. Assume there is an 80% loss of usable energy during transfers from one trophic level to another. Make a Data Table AND Graph showing energy available at each of the first 5 Trophic Levels.

23 Trophic LevelAvailable Energy [Calories] 1 st 1,600,000 2 nd 3 rd 4 th 5 th TITLE?

24 Manipulated Variable Responding Variable TITLE?

25 4. How many more humans could be fed if everyone ate from the second trophic level rather than the fifth. Is this a reasonable possibility? EXPLAIN.

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