The Chain Reaction
The Chain Reaction is a Grade 7 science concept from Amplify Science (California) Chapter 3: Indirect Effects in Ecosystems, explaining how indirect effects cascade through food webs. When Population A preys on Population B, which preys on Population C, a change in A indirectly affects C through an intermediary, demonstrating that ecosystem changes can have far-reaching consequences.
Key Concepts
An indirect effect occurs via an intermediary. For example, Population A eats Population B, and Population B eats Population C.
A change in Population A will cause a change in Population B, which will then cause a change in Population C. Thus, A affects C indirectly .
Common Questions
What is an indirect effect in an ecosystem?
An indirect effect occurs when a change in one population affects another through an intermediary species. For example, if predator A reduces prey B, and prey B normally eats organism C, then C will indirectly increase because there is less predation on it.
How does a chain reaction work in a food web?
In a food chain A eats B, B eats C: if A decreases, B population grows because fewer are eaten, and then C decreases because more B are eating C. Each link in the chain transfers effects to the next.
Why are indirect effects important in ecology?
Indirect effects mean that removing or adding one species can trigger unexpected changes throughout the ecosystem, sometimes affecting species with no direct predator-prey relationship.
What do Grade 7 students learn about indirect effects in Amplify Science?
In Chapter 3 of Amplify Science California Grade 7, students learn to trace how changes in one population propagate indirectly through food web links to affect distant populations.