Science 8 ) Develop and use models to describe the cycling of matter (e.g., carbon,
nitrogen, water) and flow of energy (e.g., food chains, food webs, biomass
pyramids, ten percent law) between abiotic and biotic factors in ecosystems.
NAEP Framework
NAEP Statement::
NAEP Statement::
Unpacked Content
Scientific And Engineering Practices:
Developing and Using Models
Crosscutting Concepts: Systems and System Models; Energy and Matter
Disciplinary Core Idea: Ecosystems: Interactions, Energy, and Dynamics
Evidence Of Student Attainment:
Students:
Categorize organisms in an ecosystem based on evidence of how they obtain energy.
Construct a food chain that differentiates between producers, primary, secondary and tertiary consumers and integrate multiple food chains into a food web.
Use relationships between organisms to develop a food web and use it to demonstrate flow of energy and predict the impacts of population changes. Construct a pyramid of biomass, given population data about organisms in the ecosystem and make calculations using data from the pyramid.
Use mathematical examples, such as the 10% law to explain why there is less energy available at each level of an energy pyramid.
Analyze data to identify patterns in the cycling of carbon, nitrogen and water in ecosystems.
Use patterns identified in the cycling of carbon, nitrogen, and water to build models of matter cycling through ecosystems.
Predict the effect of the reduction of a population of species on the carbon, nitrogen or water cycle. Teacher Vocabulary:
Autotroph Heterotroph Primary producer Primary consumer Secondary consumer Tertiary consumer Herbivore Carnivore Omnivore Detritivore Trophic levels: primary, secondary and tertiary Food chain Food web Biomass Energy pyramid Biomass pyramid Number pyramid Matter Nutrient Biogeochemical cycle Nitrogen fixation Denitrification Law of conservation of mass Knowledge:
Students know:
A food chain is a simple model representing the transfer of energy from organism to organism (e.g., sun → plant → grasshopper → mouse → snake).
Each step of a food chain represents a trophic level always starting with an autotroph in the first level and heterotrophs in the remaining levels.
The overlapping relationships between multiple food chains are shown in a food web.
An ecological pyramid is a model that can show the relative amounts of energy, biomass, or numbers of organisms at each trophic level in an ecosystem.
In an energy pyramid, only 10% of energy is passed from one trophic level to the next due to loss of energy in the form of heat caused by cellular respiration (10% rule).
In a biomass pyramid, the total mass of living matter at each trophic level tends to decrease.
In a numbers pyramid, it shows the number of organisms at each trophic level tends to decrease because there is less energy available to support organisms.
The exchange of matter through the biosphere is called the biogeochemical cycle and involves living organisms (bio), geological processes (geo), and chemical processes (chemical). Skills:
Students are able to:
Use a self-created food web diagram to predict the impact of removing one organism on other organisms within the food web.
Use data to create ecological pyramids to show flow of energy, biomass and number of organisms.
Model the cycling of matter (e.g., Carbon, water, nitrogen) through the biosphere.
Combine a food web diagram with a matter cycling diagram to provide a holistic view of the many aspects that make up an ecosystem. Understanding:
Students understand that:
Everything in an ecosystem is connected to everything else (both abiotic and biotic), either directly or indirectly.
Nutrients, in the form of elements and compounds, flow through organisms in an ecosystem (e.g., grass captures substances from the air, soil and water and converts them into usable nutrients → cow eats the grass → human eats the cow → decomposers return the nutrients to the cycle at every level). AMSTI Resources:
ASIM Module:
Alabama Alternate Achievement Standards
AAS Standard:
