A Sealed World
A Sealed World is a Grade 7 science concept from Amplify Science (California) Chapter 1: Photosynthesis, using a biodome as a model of a closed system where nothing enters or leaves except light energy. In such a sealed world, every atom of carbon, oxygen, and water must be continuously recycled, and ecosystem survival depends entirely on efficient internal matter cycling.
Key Concepts
This isolation dictates that matter —every atom of carbon, oxygen, and water—must be constantly recycled. The survival of the system depends entirely on the efficient internal cycling of finite resources.
Common Questions
What is a biodome and why is it a model of a closed system?
A biodome is a sealed environment where no matter enters or leaves — only light energy can pass through. It models a closed system because all materials inside must be recycled internally for the ecosystem to survive.
Why must matter be recycled in a closed system?
In a closed system, no new matter can be brought in from outside. The fixed supply of atoms must be reused continuously through processes like photosynthesis, respiration, and decomposition, or the system will fail.
How does Earth compare to a biodome in terms of matter cycling?
Earth is essentially a large closed system — matter does not leave the planet in significant quantities. Like a biodome, Earth depends on continuous recycling of matter through biogeochemical cycles to sustain life.
What do Grade 7 students learn from the biodome model in Amplify Science?
In Chapter 1 of Amplify Science California Grade 7, students use the biodome as a model to understand how closed systems require complete matter recycling, and then apply this to understand the global carbon cycle.