Interactions in our Environment Food Chains and Food

Interactions in our Environment Food Chains and Food Webs

Food Chains and Food Webs �Learning Goals: Describe a food chain and the effect of losing a part of that chain. �Success Criteria: I can describe a food chain/web and discuss what happens when one part of the food web is lost.

Where do we get our Energy? �All energy in ecosystems originate with the sun. As we learned last lesson, plants absorb energy and turn it into foods such as sugars and starches. �Animals eat the plants and the energy is transferred. �Carnivores and omnivores eat those animals and energy is again transferred.

A food chain is created. . sun grains chicken Chicken dinner Food Chain (def): A sequence that shows how energy and nutrients are transferred from one organism to another in an ecosystem.

Food Chains �The number of “links” in a food chain can vary, but it always starts with a producer and ends with a consumer. Blueberry bush bear 2 links 5 links: dandelion aphid ladybug robin hawk

Food Webs �In real ecosystems, food chains are not that simple. �Producers (plants) are usually eaten by many different consumers (animals) which in turn can be eaten by many other animals. �Food Web (def): A model that shows how food chains in an ecosystem are connected.

A more realistic Food Web

Your Turn. . �In your group, create a food web. �Work together to think of as many plants and animals as possible that will be part of your web. Animals/plants must be realistic and links must be accurate (e. g. A bear does not eat a lion!) �You must identify your ecosystem! �Your group will have 8 minutes to make your web. Be ready to present. �Which group will have the most connections?

Changes in Food Chains/Webs �What happens when one species is eliminated from the web? (Discuss as a class and run Gizmos simulation)

Changes in Food Chains/Webs �If one species is eliminated (e. g. goes extinct) it affects the other species in that food web. �Sometime other species will die or they may find an alternate source of food. �When any part of a food web is changed the flow of energy is affected in a food web. We will be studying energy flows next.

Let’s Review Food Webs and Introduce Energy Flows �Food Chains, Food Webs and Energy Pyramids in Ecosystems �Food chains/webs show energy moves from one organism to another but they do not show the energy is used.

Energy Flow in an Ecosystem � 1. Work with a partner to find the important information and make jot notes about the information on pages 132 -134. (Hint: divide the information into headings, following the text and use diagrams to help you illustrate and understand) � 2. Go to Gizmos in the Hub and complete the quiz for Food Chains