Unit 3 — Energy and Matter in Ecosystems
Description
Students develop models to describe how matter and energy move through ecosystems and connect this to the sun. In the first part of the unit, students observe that plants acquire materials for growth chiefly from air and water, not from soil, by documenting plant growth and water uptake over time. In the second part, students observe terrariums or use media to understand how matter moves among plants, animals, decomposers, and the environment through food webs and nutrient cycling. They learn that decomposers break down dead organisms and return materials to the soil. In the third part, students create diagrams and flowcharts to trace energy from the sun through food chains to animals, understanding that the energy in animals' food was captured by plants and is used for body repair, growth, motion, and maintaining body warmth.
Essential Questions
- Where do plants get the materials they need for growth?
- How does matter move among plants, animals, decomposers, and the environment?
- Where does the energy in an animal's food come from?
Learning Objectives
- Support an argument that plants get materials for growth chiefly from air and water, not from soil
- Develop a model describing the movement of matter among plants, animals, decomposers, and the environment
- Identify food chains and food webs showing how animals depend on plants and each other
- Understand that decomposers break down dead organisms and recycle materials back to soil
- Use models to describe that energy in animals' food was originally energy from the sun
- Explain that food provides animals with materials for body repair and growth and energy for motion and warmth
Supplemental Resources
- Markers for labeling food web diagrams for model documentation
- Chart paper for creating large-scale food webs and energy flow models for visualization
- Index cards for writing organism names when building physical food web models for kinesthetic learning
- Sticky notes for labeling components of terrariums for observation documentation
- Highlighters for tracing energy pathways in diagrams for emphasis
Crosscutting Concepts
Disciplinary Core Ideas
Science and Engineering Practices
Students use informational texts and digital sources to conduct research, gather evidence, and build knowledge across all science units. They quote accurately from texts, draw inferences, summarize and paraphrase information in science notebooks, write opinion pieces supporting claims with evidence, and incorporate multimedia components into presentations. Reading informational texts and writing research-based explanations are explicitly aligned to science performance expectations throughout all six units.
Students apply mathematical reasoning and computational thinking across all units. They measure and graph physical quantities such as weight, volume, and temperature; use coordinate plane graphing to represent scientific data; convert measurement units within standard systems; and reason abstractly and quantitatively when analyzing data as evidence for scientific explanations. Mathematical practices including modeling with mathematics and using appropriate tools strategically are integrated throughout investigation and data analysis activities.
Formative Assessments
- Students make observations of plants growing with and without soil to determine where growth materials come from
- Students record observations of terrarium ecosystems showing interactions between plants, animals, and decomposers
- Students create and refine models of food chains and food webs based on classroom and terrarium observations
- Students draw diagrams or create flowcharts tracing energy from the sun through food to animals
Summative Assessment
Students design a self-sustaining garden that provides food for a community, demonstrating understanding of how matter and energy move through ecosystems.
Benchmark Assessment
Students create a presentation that illustrates and describes the flow of energy in an ecosystem, tracing energy from the sun through organisms.
Alternative Assessment
Students may demonstrate understanding through a labeled diagram or model with teacher support, verbal explanation of food chains and energy flow, or a simplified graphic organizer showing relationships between plants, animals, and decomposers. Visual aids such as pictures or pre-made cards may be provided to help organize information about matter and energy movement.
IEP (Individualized Education Program)
Students with IEPs may benefit from graphic organizers that provide partially completed diagrams of food chains and food webs, reducing the cognitive load of organizing new information while keeping the focus on understanding energy and matter flow. Teachers should offer multiple ways to demonstrate understanding, such as allowing students to explain their ecosystem models orally or through labeled drawings rather than written explanations alone. Breaking multi-step tasks like tracing energy from the sun through a food web into smaller, numbered steps with visual anchors can support sequential processing. Providing a vocabulary reference with diagrams for key terms such as producer, consumer, decomposer, and food web will help students access content throughout the unit.
Section 504
Students with 504 plans should be given extended time during observation and recording tasks, particularly when documenting plant growth or terrarium interactions, to ensure they can process and respond without undue pressure. Preferential seating near the front during demonstrations of ecosystem models or food web diagrams supports focused attention. Providing printed copies of any diagrams or flowcharts discussed during instruction ensures students can reference content without relying solely on board displays or verbal delivery.
ELL / MLL
Multilingual learners will benefit from a visual word wall featuring key ecosystem vocabulary — such as producer, consumer, decomposer, energy, and matter — accompanied by diagrams and illustrations that convey meaning without relying solely on English text. Teachers should use visual demonstrations and real or pictured organisms when introducing food chains and food webs, making abstract concepts tangible before introducing vocabulary. Directions for observation tasks and modeling activities should be given in short, clear steps, and students should be encouraged to sketch and label diagrams in their home language first before transferring ideas to English.
At Risk (RTI)
Students who need additional support should be connected to prior knowledge about familiar living things — such as common plants and animals — before introducing the full complexity of food webs and nutrient cycles. Simplifying the scope of early tasks, such as building a two- or three-organism food chain before expanding to a full web, allows students to experience success and build confidence with the core concepts. Frequent brief check-ins during observation and modeling activities will help teachers catch misconceptions early, particularly around the idea that plants get materials from air and water rather than soil, which often runs counter to students' intuitions.
Gifted & Talented
Advanced learners can be invited to explore the concept of energy efficiency across trophic levels, investigating why less energy is available at each step of a food chain and considering what that means for ecosystem design and sustainability. When completing the summative garden design task, these students can be challenged to factor in nutrient cycling, decomposer roles, and energy transfer efficiency as constraints that must be addressed in their plan. Connecting ecosystem concepts to real-world issues such as biodiversity loss, agricultural sustainability, or urban food systems can deepen engagement and encourage higher-order thinking beyond the core content of the unit.