Teacher Portal
Ecosystems
Investigation 2
Investigation 2
Ecosystems
Phase 1 – Defined Understanding
Student Guide
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Access Teacher Guide
Student Guide with answers
Teacher PreLab
Prepare for the Experiment
Phase 2 – Dynamic Understanding
► Investigation Two Summary – Lab Goals
In Investigation Two, you studied how energy flow between levels of an ecosystem is inefficient because the organisms at each level require energy to live. During this Investigation, you:
1. Determined the amount of energy available in the plant biomass by measuring dissolved oxygen levels for 5 minutes in a sugar solution.
2. Added a “live herbivore” to the sugar solution and measured the amount of energy it consumes by observing levels of dissolved oxygen for 15 minutes.
3. Determined the amount of energy consumed by the “dead herbivore” in a plant biomass by measuring the amount of dissolved oxygen for 15 minutes.
► Investigation Two Summary – Learning Goals
Through these experiments, you concluded that:
1. The efficiency of energy transfer is affected by the use of energy byan organism. All organisms must use some energy to live, and therefore cannot store all the energy that they consume. Therefore, the transfer of energy from one level to another is not 100% efficient. This was demonstrated by the “Live Herbivore” model. The “Live Herbivore” consumed oxygen, indicating that it was using energy to live. The energy used by the herbivore to live was no longer available to any organism that might consume the herbivore.
Concept Slides
Launch and Discuss
Mathematics Concepts in This Investigation
- predict/verify results
- volume in mL
- grouping/classifying
- measuring dissolved oxygen using oxygen meter
- dissolved oxygen in mg/L
- data table
- data analysis
- decimals to the nearest tenth
- measuring mass using a triple beam balance
- mass in grams
- height in cm
- time in minutes
- line graph
- patterns/trends
- variables/constants
- skip counting by 2 and 5
- greater than/less than/equal to