Description
Students are introduced to an aquatic food web diagram that has 3 missing “mystery” organisms. After drawing inferences about those mystery organisms, a microscopic investigation is done to solve a “who eats whom” mystery. Students have a chance to revise any cases of mistaken identity. Next, students conduct and interpret a model of energy flow through a food chain. They perform calculations using their data and based on the 10% rule. Using these numbers, they consider how the model could be improved, and explain how it applies to the aquatic food web. Throughout, students seek to construct and refine their understanding of energy flow and matter cycles to answer the driving question, “How does energy flow through food chains in an ecosystem?” Note: Be sure to carefully plan the arrival of your perishables; Didinium will starve to death if not used within 1 day of receiving the culture.
Time Requirement
Teacher prep, a 50-minute class period. Pre-lab, investigation, and assessment, approximately 4 class periods.
Digital Resources
Includes 1-year access to digital resources that support 3-dimensional instruction for NGSS. Digital resources may include a teacher manual and student guide, pre-lab activities and setup videos, phenomenon videos, simulations, and post-lab analysis and assessments.
Crosscutting Concepts
Energy and Matter
Systems and System Models
Science and Engineering Practices
Using Mathematics and Computational Thinking
Developing and Using Models
Learning Objectives
- Construct a food chain using microscopic observations of 3 microorganisms.
- Describe the nature of how energy flows through food chains.
- Use physical and mathematical models to analyze the loss of energy between trophic levels.
- Explain how the flow of energy through food chains obeys the law of conservation of energy.
Prerequisite Knowledge and Skills
By the time students begin these investigations, they should know why energy is important to living things. They should have a basic understanding of the energy dynamics of photosynthesis and cellular respiration and have a degree of familiarity with aquatic ecosystems. They also should be independently proficient with the proper use and handling of a compound microscope.