{"id":1604,"date":"2018-01-02T11:53:06","date_gmt":"2018-01-02T16:53:06","guid":{"rendered":"http:\/\/www.horizon-research.com\/ASSET\/?page_id=1604"},"modified":"2019-04-15T16:22:57","modified_gmt":"2019-04-15T20:22:57","slug":"student-experience-2-what-are-decomposers","status":"publish","type":"page","link":"https:\/\/www.horizon-research.com\/ASSET\/getting-started-interdependence\/driving-question-pathway-the-mystery-at-sunrise-farm-pond\/the-mystery-at-sunrise-farm-pond-part-two\/student-experience-2-what-are-decomposers\/","title":{"rendered":"Student Experience 2: What are decomposers?"},"content":{"rendered":"

\"decomposers\"<\/a>
\nPrint<\/a>\n

Purposes<\/em><\/h3>\n
    \n
  1. To help students understand what decomposers need to survive.<\/li>\n
  2. To help students understand that decomposers are consumers.<\/li>\n<\/ol>\n

    Description<\/em><\/h3>\n

    Ask students to look at their drawings from Part One and name the various organisms<\/a> found in Sunrise Farm Pond.\u00a0 Ask them to name which of the organisms are producers<\/a> (algae and underwater plants).\u00a0 Once the producers have been determined, ask them what the other organisms in the pond are (perch, minnows, mayfly larvae).\u00a0 If they are not familiar with the term \u201cconsumer,\u201d ask students to describe what these organisms need to survive.\u00a0 They should realize that the things the organisms need to survive are the same things humans need (i.e., food, water, and air; particularly oxygen).\u00a0 Let the students know that these organisms are all in a group called consumers, and that, unlike producers, consumers are organisms that cannot make food within their own bodies.<\/p>\n

    Crosscutting Concepts<\/div>
    \n
    Patterns <\/b><\/a> Applying what they learned about producers’ needs in Part One of the pathway, students are able to classify organisms based on patterns of what they need to survive.\u00a0 Emphasizing these patterns (i.e., the commonalities and differences in needs of various organisms) can support students’ ability to differentiate between producers and consumers. <\/div><\/div> <\/div><\/div>\n

    Recall with students that in the first student experience, they saw videos with rotting fruit.\u00a0 Another way to describe what happened to the fruit is \u201cdecomposition.\u201d\u00a0 Ask students what they think caused the fruit and vegetables to decompose.\u00a0 They may mention the bugs or the mold that appeared on the fruit and vegetables in the time-lapse videos.\u00a0 Let students know that these are decomposers, and that decomposers are necessary for decomposition.\u00a0 Take a class poll about whether students think decomposers are producers or consumers, and call on volunteers to defend their answers.\u00a0 If they are unsure, ask students to think about what producers and consumers need to survive.\u00a0 Record these lists for all students to see.<\/p>\n

    Next, let students know they will be conducting an experiment to explore whether decomposers are producers or consumers.\u00a0 Take five paper plates (one for each condition) and place a strawberry, piece of melon (watermelon, cantaloupe, etc.), and piece of bread on each.\u00a0 Tell students that they are going to place the plates of food in different conditions to test what helps or hinders decomposers.\u00a0 Ask students to make suggestions based on the lists that they created for the needs of producers and consumers.\u00a0 In the end, you will want to make sure that you have the following conditions: one plate in sunlight, one in dark, one where each item has been dunked in water.\u00a0 Students may make other suggestions, such as placing a plate in cold or heat or adding dirt.\u00a0 Once the five conditions have been decided upon, add the necessary items to the plates and place each in a gallon zip bag.\u00a0 Then place the bags in the agreed-upon locations.\u00a0 Have students record observations for each plate at regular intervals for one week.\u00a0 It is not necessary to pause instruction during this week; you can continue with the next student experiences as the experiment runs its course.<\/strong><\/p>\n

    Science Practices<\/div>
    \n Planning and Carrying Out Investigations <\/b><\/a> Students work collaboratively to design a class investigation focused on decomposition.\u00a0 In setting up the investigation, students make suggestions for conditions to test and make predictions about what will happen under the various conditions. Over the course of a week, students make observations to gather evidence related to decomposers’ needs. <\/div><\/div>\n
    Analyzing and Interpreting Data <\/b><\/a> Although students’ data is most likely to be qualitative (e.g., descriptions and pictures of what they observe), encourage students to also consider ways for incorporating quantitative measurements (e.g., how many different types of mold\/fungi, how many visible spots of each, estimated size or proportion of food that is covered). <\/div><\/div> <\/div><\/div>\n

    \"mold<\/a><\/p>\n

    Before<\/u> (Top row: plate kept in dark, plate kept in sunlight; Bottom row: plate kept in refrigerator, plate with water added on top of the foods, plate with dirt added on top of the foods)<\/em>
    \n<\/em><\/p>\n

    \"mold<\/a><\/p>\n

    After One Week <\/u>(Top row: plate kept in sunlight, plate with dirt added on top of the foods, plate kept in dark, plate with water added on top of the foods; Bottom row: plate kept in refrigerator)<\/em><\/p>\n

    Questions to Ask Students<\/em><\/h3>\n

    On the first day:<\/u><\/p>\n