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Testing Conditions that Promote Decomposition

Unit Plan: Decomposer DynamicsLesson: 5 Time: Session 1 (40 min), Session 2 (40 min), Session 3-5 (40 min), Session 6 (1 hr) Setting: Classroom
3-5, 6-8Schoolyard Ecology
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Students test factors that promote the growth of microbes, then use their findings to make compost.


    Students will be able to: Understand that invisible spores of microbes are in the air, water, and on all non-sterile surfaces, discover that certain physical conditions, such as moisture and warmth, help microbes grow, explain the connection between the growth of microbes on dead plants and decomposition, refine their experimenting skills



    For the Class:

    • 2.5 gallon (30x15x17 cm) plastic animal cage with cover (or a similar clear plastic container to use as a decomposition chamber)
    • clear plastic bag large enough to line the decomposition chamber
    •  6 cups of alfalfa hay
    • 6 cups of hardwood shavings
    • materials to vary conditions for growing microbes

     Session 1

    For each pair of students

    • copy of "Research Proposal"

    Session 2

    For the class

    • miscellaneous containers

    For each pair of students

    • 4 sandwich-size ziplock bags
    • masking tape or permanent marker

    Session 3-5

    For the class

    • measurement and observation tools

    For each pair of students

    • 2 hand lenses
    • copy of "Science Fair Story #3"
    • copy of "Science Fair Story #4"
    • copy of Science Fair Story #5

    See Lesson Resources for further details.

    Lesson Files

    Testing Conditions that Promote Decomposition

    Benchmarks for Science Literacy

    5D Interdependence of Life, 5E Flow of Matter and Energy, 12C Manipulation and Observation

    NYS Standards

    MST 4- Physical setting, living environment and nature of science, MST 7- Problem solving using mathematics, science, and technology (working effectively, process and analyze information, presenting results)
    Next Generation Science Standards

    Science and Engineering Practices

    Asking questions and defining problems, Planning and carrying out investigations, Analyzing and interpreting data

    Cross Cutting Concepts

    Patterns, Cause and effect

    Disciplinary Core Ideas

    LS2A: Interdependent Relationships in Ecosystems, LS2B: Cycles of Matter and Energy Transfer in Ecosystems
    New York State Science Learning Standards

    Performance Expectations

    MS-LS2-1. Analyze and interpret data to provide evidence for the effects of resource availability on organisms and populations of organisms in an ecosystem., MS-LS2-4. Construct an argument supported by empirical evidence that changes to physical or biological components of an ecosystem affect populations.

    Hogan, Kathleen. Eco-Inquiry: A Guide to Ecological Learning Experiences for the Upper Elementary/Middle Grades. Kendall/Hunt Publishing Company, PO Box 1840, 4050 Westmark Drive, Dubuque, IA 52004-1840., 1994.