How Ecosystems Work Energy Flow in Ecosystems

Objectives 5 things you should know 1.Be able to describe how energy is transferred from the sun to producers and then to consumers 2.Be able to describe one way in which consumers are dependent on producers 3.Be able to describe two types of consumers 4.Be able to explain how energy transfer in a food web is more complex than energy transfer in a food chain 5.Be able to explain why an energy pyramid is a representative of trophic levels

Life Depends on the Sun  Energy enters an ecosystem when plants, algae and some bacteria capture sunlight to make sugar molecules called carbohydrates through a process called photosynthesis  CO2 +H2O+Light  C6H12O6 +O2  When and animal eats a plant some of the energy is transferred from the plants to the animal.  Organisms use this energy to move, grow and reproduce.

From Producers to Consumers Coyote-Secondary Consumer- Organisms that Get their energy by eating primary consumers Heterotrophs Rabbit-Primary Consumer- organisms that get their energy by eating other organisms Heterotrophs Clover-Producer is an organism that makes its own food Autotrophs

What Eats What ?  Organisms are classified based on what they eat  Consumers that eat only producers are Herbivores- Plant Eaters  Consumers that eat only other consumers are Carnivores-Meat Eaters  Consumers that break down dead organism- Decomposers  Consumers that eat plants and animals are Omnivores- Eaters of All Producers Herbivores Carnivore Omnivore Decomposers

Burning the Fuel- Getting the Energy  The process of breaking down the food and releasing the energy is called Cellular Respiration The cells in your body use the oxygen you breathe to release the energy from food to carry out daily activties C6H12O6+6O2  6CO2+6H2O+Energy

Energy Transfer  Each time an organism eats another, energy is transferred  Food chains, food webs and feeding layers or Trophic levels tells us how much energy is transferred between organisms in ecosystems

Food Chains  A food chain is a sequence in which energy is transferred from one organism to the next as each organism eats another

Food Web  A food web shows many feeding relationships that exist in an ecosystem  Ecosystems almost always contain many more species than a food chain contains  Each step in the transfer of energy is known as a trophic level  90%is used to live  10% is stored, may be passed on to the next level

Energy Pyramid 10% for Each Level 1 Tertiary Consumer 10 Secondary Consumers 100 Primary Consumers 1000 Producers

What do you know? 1.How is energy transferred from the sun to producers and then to consumers? 2.Describe one way in which consumers are dependent on producers. 3.Explain the difference among herbivores, carnivores and omnivores. 4.Explain how energy transfer in a food web is more complex than energy transfer in a food chain. 5.Explain why an energy pyramid is a good representative of trophic levels. 6.How much energy is available to be passed on to the next trophic level? 7.A lake has snails, algae, catfish, worms, clams, raccoons lake perch and water beetles. Who eats who? Place the organisms in the order they might be consumed in either a food chain or web.

Food Chain Mobiles-Worth 100 pts.-90 pts for the rubric elements + 10 pts for being turned in on time Due Friday  For Homework you are going to build a hanging mobile showing energy transfer relationship among groups of organisms from an ecosystem. Use the rubric below and the mobile instructions to complete your project.  Full credit will given to projects submitted on time.  Loss of 10 points for every day late Element 3-All Elements Present and Energy Relationships in correct order 2-All Elements Present, however relationships not in correct order 1-Some Elements Missing and Relationships not in correct order Trophic or feeding levels All trophic levels present, 3 trophic levels present 1-2 trophic levels present Energy Transfer Relationships Correct energy transfer relationships Incorrect order for energy transfer relationships Chain Disruption Describes what happens to trophic levels when one level removed_____________ Does not describe what happens to trophic levels when one level removed