{"id":1600,"date":"2018-01-02T11:51:48","date_gmt":"2018-01-02T16:51:48","guid":{"rendered":"http:\/\/www.horizon-research.com\/ASSET\/?page_id=1600"},"modified":"2025-10-29T19:41:11","modified_gmt":"2025-10-29T23:41:11","slug":"the-mystery-at-sunrise-farm-pond-part-two","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\/","title":{"rendered":"The Mystery at Sunrise Farm Pond (Part Two: Decomposers)"},"content":{"rendered":"

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

Navigating this Part of the Pathway<\/strong><\/h3>\n

This part of the pathway provides students with experiences that allow them to continue to piece together an answer to the overall driving question: Why are the fish dying in Sunrise Farm Pond? \u00a0In particular, Part Two of the pathway introduces students to decomposers. \u00a0Students begin by watching videos of decomposing fruits and vegetables and considering what caused them to rot.\u00a0 They set up their own experiments with decomposing foods in various conditions in order to determine what decomposers need (and to see that decomposers are consumers, not producers).\u00a0 Next, students learn about the various types of organisms<\/a> that are decomposers.\u00a0 They also discuss the important role decomposers play in recycling nutrients in the ecosystem<\/a>.\u00a0 Finally, the students revisit their cross-sectional pond\u00a0model and make revisions using their emerging understanding about decomposers and the role they might play in Sunrise Farm Pond.<\/p>\n

Disciplinary Core Ideas<\/div>
Click on the links to view the K-12 progression for each listed DCI in a new tab.
\n5.LS2.A<\/strong> (Interdependent Relationships in Ecosystems)<\/a>
\nThe food of almost any kind of animal can be traced back to plants.\u00a0 Organisms are related in food webs in which some animals eat plants for food and other animals eat the animals that eat plants.\u00a0 Some organisms, such as fungi and bacteria, break down dead organisms (both plants or plants parts and animals) and therefore operate as \u201cdecomposers.\u201d Decomposition eventually restores (recycles) some materials back to the soil. <\/b> Organisms can survive only in environments in which their particular needs are met.\u00a0 A healthy ecosystem is one in which multiple species of different types are each able to meet their needs in a relatively stable web of life.\u00a0 Newly introduced species can damage the balance of an ecosystem. <\/div><\/div>\n
5.LS2.B<\/b> (Cycles of Matter and Energy Transfer in Ecosystems)<\/a>
\nMatter cycles between the air and soil and among plants, animals, and microbes as these organisms live and die. Organisms obtain gases, and water, from the environment, and release waste matter (gas, liquid, or solid) back into the environment. <\/div><\/div>\n(NGSS Lead States, 2013)<\/div><\/div>\n

Connections to Other Pathway Parts<\/strong><\/h3>\n

Part Two of the pathway builds on the ideas discussed in Part One and serves to connect the initial disturbance (i.e., fertilizer runoff) with depleted oxygen in the pond, in part due to decomposers using the oxygen as they consume<\/a> dead algae.\u00a0 The three pathway parts together represent the natural sequence of events that occurs when a pond is overloaded with nutrients.\u00a0 Therefore, all pathway parts should be included in instruction and done in order.<\/p>\n

Teacher Content Background<\/strong><\/h3>\n

Decomposers<\/abbr>, such as some bacteria, fungi, and earthworms, are consumers that break down dead organisms (or parts of organisms).\u00a0 Decomposition eventually recycles some materials back to the environment, making necessary resources available to producers.<\/p>\n

The pond at Sunrise Farm, like all ponds, contains bacteria in addition to the algae and other organisms students learned about in Part 1.\u00a0 Many of the bacteria are microbial decomposers.\u00a0 These bacteria consume the dead material in the pond, including, in this case, the dead algae.\u00a0 The bacteria use oxygen in their process of consuming the algae, and because there are many dead algae to consume, a lot of the pond\u2019s oxygen is used in this process.<\/p>\n

Also in the process of decomposing algae, the bacteria release carbon dioxide and nutrients that can be used by the producers<\/a> in the pond.\u00a0 The algae use these products to grow, which can also contribute to the increase in algae in the pond.<\/p>\n

Student Thinking<\/strong><\/h3>\n

Students are often unfamiliar with decomposers and decomposition.\u00a0 They tend to discount the important function that decomposers and decomposition play in an ecosystem, likely due to their unfamiliarity (Leach et al., 1992; \u00d6zkan et al., 2004).\u00a0 Some believe that decomposition is a process that occurs in the absence of decomposers (i.e., that material decomposes on its own) (\u00c7etin, 2007; Ero-Tolliver, Lucas, & Schauble, 2013; Grotzer, 2009; Helld\u00e9n, 1998; Hogan & Fisherkeller, 1996; Leach et al., 1992, 1995).\u00a0 Others who accept that decomposition involves decomposers see the decomposers as the end station of the process; that is, they tend to think that decomposed material becomes a part of the decomposer rather than being converted into resources to be used by the ecosystem (Hogan, 2000; Leach et al., 1996a).<\/p>\n

Students also are uncertain about which organisms perform decomposition and often do not associate microbes with decomposition (\u00c7etin, 2007; Grotzer, 2009; Grotzer, Basca, & Donis, 2011; Leach et al., 1992).\u00a0 Students often associate a negative connotation with the word \u201cbacteria,\u201d which may interfere with their ability to see microbes as beneficial (Spring and Harr, 2014).<\/p>\n

Finally, students frequently have an aversion to decomposition because they think it is \u201cgross\u201d or \u201cyucky.\u201d<\/p>\n

Student Experiences<\/strong><\/h3>\n

Student Experience 1: What happened to the fruit and vegetables?<\/b><\/a> (Students observe and discuss a time-lapse video of fruit over 74 days.) 5.LS2.A<\/span><\/a> CCC: Cause and Effect<\/span><\/a><\/p>\n

Student Experience 2: What are decomposers?<\/b><\/a> (Students will consider whether decomposers are producers or consumers and set up an experiment to observe decomposition.) \u00a05.LS2.A<\/span><\/a>\u00a0\u00a0SEP: Planning and Carrying Out Investigations<\/span><\/a>\u00a0SEP: Analyzing and Interpreting Data <\/span><\/a> CCC: Patterns<\/span><\/a><\/p>\n

Student Experience 3: What are decomposers?<\/b> (Continued)<\/a> (Students discover the types of organisms that are decomposers.) \u00a05.LS2.A<\/span><\/a><\/p>\n

Student Experience 4: What do decomposers do? <\/b><\/a>(Students consider the role decomposers play in the ecosystem.) \u00a05.LS2.A<\/span><\/a>\u00a0\u00a0SEP: Constructing Explanations <\/span><\/a><\/p>\n

Student Experience 5: How should we revise our pond model?<\/b><\/a> (Students revisit the mystery at the Sunrise Farm Pond and revise their\u00a0models based on new ideas.) \u00a05.LS2.A<\/span><\/a>\u00a0\u00a05.LS2.B<\/span><\/a> SEP: Developing and Using Models<\/span><\/a> SEP: Constructing Explanations <\/span><\/a> CCC: Cause and Effect<\/span><\/a><\/p>\n

Student Experience 6: More of the story<\/b><\/a>\u00a0 (Students hear more of the story from the Mystery at Sunrise Farm Pond and discuss how it relates to their pond models.) \u00a05.LS2.A<\/span><\/a> SEP: Developing and Using Models<\/span><\/a>\u00a0SEP: Asking Questions<\/span><\/a> CCC: Cause and Effect<\/span><\/a>\u00a0CCC: Stability and Change <\/span><\/a> CCC: Systems and Systems Models<\/span><\/a><\/p>\n","protected":false},"excerpt":{"rendered":"

Navigating this Part of the Pathway This part of the pathway provides students with experiences that allow them to continue to piece together an answer to the overall driving question: Why are the fish dying in Sunrise Farm Pond? \u00a0In particular, Part Two of the pathway introduces students to decomposers. \u00a0Students begin by watching videos Read the full article…<\/a><\/p>\n","protected":false},"author":2,"featured_media":0,"parent":1652,"menu_order":0,"comment_status":"closed","ping_status":"closed","template":"","meta":{"footnotes":""},"class_list":["post-1600","page","type-page","status-publish","hentry"],"_links":{"self":[{"href":"https:\/\/www.horizon-research.com\/ASSET\/wp-json\/wp\/v2\/pages\/1600","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.horizon-research.com\/ASSET\/wp-json\/wp\/v2\/pages"}],"about":[{"href":"https:\/\/www.horizon-research.com\/ASSET\/wp-json\/wp\/v2\/types\/page"}],"author":[{"embeddable":true,"href":"https:\/\/www.horizon-research.com\/ASSET\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/www.horizon-research.com\/ASSET\/wp-json\/wp\/v2\/comments?post=1600"}],"version-history":[{"count":10,"href":"https:\/\/www.horizon-research.com\/ASSET\/wp-json\/wp\/v2\/pages\/1600\/revisions"}],"predecessor-version":[{"id":2803,"href":"https:\/\/www.horizon-research.com\/ASSET\/wp-json\/wp\/v2\/pages\/1600\/revisions\/2803"}],"up":[{"embeddable":true,"href":"https:\/\/www.horizon-research.com\/ASSET\/wp-json\/wp\/v2\/pages\/1652"}],"wp:attachment":[{"href":"https:\/\/www.horizon-research.com\/ASSET\/wp-json\/wp\/v2\/media?parent=1600"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}