Ecosystems Chapter 2, sections 1

Bell Work 12-2-09 What is the difference between a food web and a food chain?

Video Preview Ecosystems and Biomes, 10 minutes Disk 2 What climatic conditions are common to all deserts?

Reading Preview Read the 3 Key Concepts page 42 Read and try to define the key terms verbally What is an ecosystem? What are some things you know about an ecosystem?

Energy Flow in Ecosystems Discover Activity, page 42 Guess at what the food is made out of Read page 42-43 with a partner. One partner reads a paragraph aloud, and then the other partner summarizes the paragraph’s concepts. Switch roles until they have finished the entire page. complete Notes worksheet, page 1 Rewrite definitions on flashcards as you go Need flashcard template 1. Figure 1 answer- break down wastes and dead organisms and recycle these materials.

Energy Roles Ecosystem roles are based primarily on the way organisms obtain energy. Look at Figure 1, page 43. What organisms in this ecosystem would you find in each role? Think about your backyard or the school grounds. What are the producers, consumers, and decomposers in this ecosystem? Name 2 of each. Producers: grass, trees; Consumers: worms, birds; Decomposers: mushrooms, bacteria (unseen) Similar answers.

Fun Fact Not all ecosystems require light. Some surrounding deep-sea hydrothermal vents are too far below the water surface to receive sunlight. Bacteria living near the vents make food by harnessing energy from chemicals in the water.

Pictures of Chemosynthesis http://www.ocean.udel.edu/deepsea/level-2/chemistry/chemo.html

Tube Worm http://www.ceoe.udel.edu/deepsea/level-2/creature/tube.html

Photosynthetic vs. Chemosynthetic food chains. Chemosynthesis Photosynthetic vs. Chemosynthetic food chains.                                                 Microscopic views of chemosyntetic microbes. The chemicals in hydrothermal vent fluid would be toxic to most forms of life familiar to us, but amazingly, a unique ecosystem has evolved to live at hydrothermal vents. These organisms are not dependent on sunlight and photosynthesis, but instead rely on chemosynthesis, a process in which certain microbes use chemicals in the vent water to produce energy. They in turn form the base for an entire food chain of animals. Chemosynthetic microbes grow on and below the seafloor and even within other animals at the vents. Version 2.0                                                                                                 page 12 of 1

Compare photosynthesis and chemosysthesis. BW 12-4-08 Compare photosynthesis and chemosysthesis.

Food Chains and Food Webs Read pages 44 Observe Figure 2 Which organisms in the food web are acting as herbivores? Which are carnivores? Name a type of consumer and explain how it is classified. Figure 2 is the next slide.

- Energy Flow in Ecosystems

Linking Energy Pathways Food web includes several food chains. Observe figure 2, page 45. With only one top consumer, the fox, how many food chains are in the web? What are the producers in this food web? What are the first-level consumers? The second-level consumers? At least 6 Grasses, trees, other plants Rabbit mouse, grasshopper, carpenter ant Mouse, garter snake, shrew, fox, woodpecker

Con’t What are the third-level consumers? How can the mouse be both a first- and second-level consumer? How do decomposers gain energy? Draw a food chain from a Prairie Dog ecosystem. (No more than 3-4 organisms.) Garter snake, fox It’s an omnivore that eats both plants and insects. They consume wastes and remains. Combine student’s food chains to make a food web within the group.

Weaving a Food Web Page 44 Materials- yarn How many organisms were affected by the removal of just one organism? What does this activity show about the importance of each organism in a food web?

BW 12/08/08 Draw a food web. You may draw pictures and use words. Include 8 living organisms including plants, animals, scavengers, YOU, fungi and decomposers. Be sure the arrows are pointing the correct direction.

Web Sites www.scilinks.org Log in as “guest” Web Code: scn-0521 More web sites at Ikeepbookmarks.com

Energy Pyramids Look at Figure 3 on page 46. How are the level grouped? What does each level look like? This energy pyramid shows how much energy each group has. Start observing at the bottom of the pyramid, where there is the most energy and then move up. Each level you lose more energy. Why start at the bottom of the pyramid where the plants are?

Reading Energy Pyramids Read page 46-47. Why is the pyramid shape useful for showing the energy available at each of the levels of a food web? The shape shows how availabale energy decreases at higher levels of a food web.

Visualizing Energy Transfers Divide into groups of 3. Materials: Scissors and graph paper 1st student- producer, 10 by 10 block of squares (total amount of food energy) Cut a row of 10 squares off and pass it on to the 2nd student, the “first level consumer”. Cut one square from the row and pass it to the third student “2nd level consumer”. FACT- Only a small portion of the original energy stored in the producer reaches the second-level consumer.

Energy Pyramid Drawing Draw a empty pyramid on the board. Divide it into 4 horizontal sections. Number 1-4 from bottom to top. Which level will include the producers? Which level will include the top consumer? Which levels include consumers? Which level represents the most available energy? The least available energy? Which level supports the fewest organisms? 1 4 2,3 and 4

BW 12-7-09 Why are there relatively few 3rd level consumers such as an owl in an ecosystem?

Answer to BW So much energy is lost at each level of the food pyramid that there is not enough energy to support very many third-level consumers.

Assessment Complete page 47, ALL QUESTIONS Write in complete sentences. Label your paper with the page number. Label all questions with a number and a letter. Example- 1a. 1b.

Interactive Web Sites Basic Food Web http://www.harcourtschool.com/activity/food/food_menu.html Create a Food Web- print out http://www.vtaide.com/png/foodweb.htm 4 food webs to choose from http://www.gould.edu.au/foodwebs/kids_web.htm Food Web Game http://gingerbooth.com/coursewareCBC/ms/kerplunk/cards/instructions.html#howto

Water Cycle 2-2 Read pages 48-49 and answer the questions in your packet. http://phschool.com/webcodes10/index.cfm?wcprefix=cfp&wcsuffix=4024&fuseaction=home.gotoWebCode&x=0&y=0