LabLearner—The Science of Learning
LabLearner—The Science of Learning

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Ecosystems

Investigation 3 – PreLab

 

 

 

 

 

 

 

Back to Investigation 3

ZERO-IN

Italicized font represents information to be shared orally or physically completed with the students at this time.

The non-italicized font represents additional information included to support the teacher’s understanding of the content being introduced within the CELL.

ASK WHY

Remind students that they depend on healthy ecosystems for their survival. Healthy ecosystems perform essential services that we depend on, including clean air, clean water, food, clothing, fuel, and lumber products. In addition, healthy ecosystems regulate floodwaters and keep lands fertile and crops pollinated.

BRANCH OUT

Remind students that natural resources technicians perform a variety of duties relating to the maintenance and restoration of woodland, wetland, prairie, and aquatic natural areas.

GET FOCUSED

Inform students that the Investigation is designed to help them to answer the following Focus Questions:

  • What is the relationship between the energy and biomass of producers and the levels that an ecosystem can support? The amount of energy that is stored by producers determines the amount of biomass they can form. The amount of biomass and energy at the producer level determines the amount of biomass and energy that can be produced in each of the upper levels of the ecosystem. As the amount of biomass and energy increases in upper levels, the greater the number of levels an ecosystem can support.
  • What affects the amount of energy in an ecosystem? The amount of energy in an ecosystem is determined by the amount of biomass in the ecosystem.

Note: These questions are located in students’ SDRs at the beginning and end of the Investigation.

Note: These are succinct responses to the Focus Questions and are placed here for your reference at this time. Fully developed responses to the Focus Questions can be found on the PostLab page.

GO DEEPER

As a class, read the Background(s) in the Investigation. Have students read the information aloud or silently to themselves. When students have finished, discuss the following concepts as a class:

  • Ecologists cannot determine exact amounts of biomass for large ecosystems, but he or she can estimate these amounts by taking equal-sized samples from different areas of the ecosystem. The ecologist can then use the average amount of biomass to calculate an estimated total biomass for the ecosystem being studied. 
  • Biomass increases as plants grow.
  • Plants grow because they undergo photosynthesis.
  • Plants use photosynthesis to capture light energy from the Sun.
  • The captured light energy is stored in the plant’s biomass.

Note: These concepts are integrated into the Background(s) and are used to deepen students’ comprehension of the big ideas.

LEARN THE LabLearner LINGO

The following list includes Key Terms that the teacher should introduce, as appropriate, within the CELL. These terms should be used, as appropriate, by teachers and students during everyday classroom discourse.

  • ecosystem
  • producers
  • consumers
  • detritivore
  • detritus
  • trophic level
  • biomass
  • Law of Conservation of Energy
  • Law of Conservation of Matter

Note: Definitions of these terms can be found on the Introduction page to the CELL.

Note: Additional words may be bolded within the Background(s). These words are not Key Terms and are strictly emphasized for exposure at this time.

SET FOR SUCCESS

As a class, review what was discovered in Investigations One and Two.

    • Note: Students discovered that the amount of energy in each level of an ecosystem is smaller than the amount of energy in the level below it and this indicates that energy transfer is inefficient.

      Note: Students also discovered that higher levels of an ecosystem have smaller amounts of biomass than the levels below them.

      Note: The models in Investigation Two demonstrated that energy transfer between levels of an ecosystem is inefficient because all of the energy consumed by an organism is not transferred to its consumer. Students discovered that one of the primary reasons for this inefficiency was energy usage during cellular respiration.

      • Direct students to complete the Recall section in their SDRs. Student answers may vary.
        • Do all ecosystems have the same number of levels of consumers?
        • How does the amount of photosynthesis determine the number of levels an ecosystem can support?
      • Play the video below. Stop to ask students questions or answer students’ questions when necessary. Remind students to follow along with their SDRs and make any notes that they think might be helpful.
      • After the video, direct students to divide into their lab groups to discuss their strategy for the lab. For example, they may assign certain group members to perform specific functions during the lab.

      Note: The purpose of the video is to allow students to anticipate the laboratory experience they will soon encounter. Students should leave this PreLab session with a firm idea of what to expect and how to perform in the lab.

      Note: Homework is posted below the video.

    HOMEWORK

    Tell students that they should review the Investigation in preparation for the Lab.