1. End Show 3–2 Energy Flow Slide 1 of 41 Copyright Pearson Prentice Hall Ecological Pyramids The amount of energy or matter in an ecosystem can be represented by an ecological pyramid. An ecological pyramid is a diagram that shows the relative amounts of energy or matter contained within each trophic level in a food chain or food web.

2. End Show 3–2 Energy Flow Slide 2 of 41 Copyright Pearson Prentice Hall Ecological Pyramids Ecologists recognize three different types of ecological pyramids: energy pyramids biomass pyramids pyramids of numbers

3. End Show 3–2 Energy Flow Slide 3 of 41 Copyright Pearson Prentice Hall Ecological Pyramids 0.1% Third-level consumers 1% Second-level consumers 10% First-level consumers 100% Producers Energy Pyramid: Shows the relative amount of energy available at each trophic level. Only part of the energy that is stored in one trophic level is passed on to the next level.

4. End Show 3–2 Energy Flow Slide 4 of 41 Copyright Pearson Prentice Hall Ecological Pyramids The more levels that exist between a producer and a top-level consumer in an ecosystem, the less energy that remains from the original amount. Only about 10 percent of the energy available within one trophic level is transferred to organisms at the next trophic level.

5. End Show 3–2 Energy Flow Slide 5 of 41 Copyright Pearson Prentice Hall Ecological Pyramids Biomass Pyramid The total amount of living tissue within a given trophic level is called biomass. Biomass is usually expressed in terms of grams of organic matter per unit area. A biomass pyramid represents the amount of potential food available for each trophic level in an ecosystem.

6. End Show 3–2 Energy Flow Slide 6 of 41 Copyright Pearson Prentice Hall Ecological Pyramids 50 grams of human tissue 500 grams of chicken 5000 grams of grass Biomass Pyramid: Represents the amount of living organic matter at each trophic level. Typically, the greatest biomass is at the base of the pyramid.

7. End Show 3–2 Energy Flow Slide 7 of 41 Copyright Pearson Prentice Hall Ecological Pyramids Pyramid of Numbers A pyramid of numbers shows the relative number of individual organisms at each trophic level.

8. End Show 3–2 Energy Flow Slide 8 of 41 Copyright Pearson Prentice Hall Ecological Pyramids Pyramid of Numbers: Shows the relative number of individual organisms at each trophic level.

9. End Show 3–2 Energy Flow Slide 9 of 41 Copyright Pearson Prentice Hall Ecological Pyramids For some ecosystems, the shape of the pyramid of numbers is the same as that of the energy and biomass pyramids. However, in ecosystems where there are fewer producers than there are consumers, such as a forest ecosystem, the pyramid of numbers would not resemble a typical pyramid at all.

10. End Show - or - Continue to: Click to Launch: Slide 10 of 41 Copyright Pearson Prentice Hall 3–2

11. End Show Slide 11 of 41 Copyright Pearson Prentice Hall 3–2 The main source of energy for life on Earth is a.organic chemical compounds. b.inorganic chemical compounds. c.sunlight. d.producers.

12. End Show Slide 12 of 41 Copyright Pearson Prentice Hall 3–2 Organisms that feed on plant and animal remains and other dead matter are a.detritivores. b.carnivores. c.herbivores. d.autotrophs.

13. End Show Slide 13 of 41 Copyright Pearson Prentice Hall 3–2 How does a food web differ from a food chain? a.A food web contains a single series of energy transfers. b.A food web links many food chains together. c.A food web has only one trophic level. d.A food web shows how energy passes from producer to consumer.

14. End Show Slide 14 of 41 Copyright Pearson Prentice Hall 3–2 In a biomass pyramid, the base of the pyramid represents the mass of a.heterotrophs. b.primary consumers. c.producers. d.top level carnivores.

15. End Show Slide 15 of 41 Copyright Pearson Prentice Hall 3–2 The amount of energy represented in each trophic level of consumers in an energy pyramid is about a.10% of the level below it. b.90% of the level below it. c.10% more than the level below it. d.90% more than the level below it.