Ecosystem in a Bottle
Phenomenon:
A mouse dies in a sealed jar. However, when a plant is also placed in the sealed jar the mouse thrives.
Three-dimensional Performance Task:
Develop an argument based on evidence that organisms depend on one another and on non-living things in their environment.
Model
Students develop a model of an ecosystem to investigate factors necessary to maintain stability in an ecosystem.
Investigate
Students observe the natural world on at least three different scales and define the boundaries of each system.
Obtain Information
Students read to obtain information about how plants and animals depend on each other for survival.
Analyze Data
Students analyze data from a historical experiment performed in 1771 by Joseph Priestly.
Explanation:
The mouse dies because it runs out of air to breathe. (The candle burning in the sealed container uses up all of the oxygen.) Putting a green plant in the jar and exposing it to sunlight permits the candle to burn and the mouse to breathe. This is because plants produce oxygen. This experiment provides evidence that plants and animals depend on one another and on non-living things in their environment (e.g., air). This experiment also provides evidence that matter cycles and energy flows in the Earth system.
Application (Optional STEM Project):
Students design an ecosystem in a bottle that remains stable for at least three months.
NGSS Standard:
MS-LS2-3 Develop a model to describe the cycling of matter and flow of energy among living and nonliving parts of an ecosystem.
[Clarification Statement: Emphasis is on describing the conservation of matter and flow of energy into and out of various ecosystems, and on defining the boundaries of the system.]
Utah SEEd Standard:
6.4.3 Develop a model to describe the cycling of matter and flow of energy among living and nonliving parts of an ecosystem.
[Emphasize food webs and the role of producers, consumers, and decomposers in various ecosystems.]
Recommended Teaching Sequence:
Day 1: Students observe the natural world on at least three different scales and define the boundaries of each system.
Day 2: Students analyze data from a historical experiment performed in 1771 by Joseph Priestly. Students read to obtain information about how plants and animals depend on each other for survival. Students develop a written argument based on evidence that organisms depend on one another and on non-living things in their environment.
Day 3: Students design a model ecosystem in a sealed jar to investigate how matter cycles and energy flows in the Earth system. Students record observations of their ecosystem in a bottle over time (e.g., two months).
TWO MONTHS LATER
Day 4: Students evaluate design solutions, identifying which designs best met the criteria and constraints of the problem. Students reflect on ways to improve their design.
Formative Assessment:
Use what students have written in their science notebooks as a formative assessment, including the observations they recorded and their written explanation for the phenomenon. Do students understand that matter cycles and energy flows among the living and nonliving components of an ecosystem? Can students justify why they included each component in their ecosystem in a bottle?
Lesson Contributor:
April Mitchell, Science Coach, Salt Lake City School District