IB Biology SL Interaction and Interdependence Concepts

Interaction and Interdependence explains how cells, organisms and ecosystems exchange information, energy and matter through regulated relationships and environmental feedback.

Exam analysis

Published Concept evidence in Interaction and Interdependence clusters around regulated processes, signalling, defence and ecological relationships. The recurring pattern is explaining how interactions control biological outcomes, from enzyme activity and energy transfer to population change and ecosystem cycling.

Most tested topics

Transfers of energy and matter69%
Enzymes and metabolism56%
Photosynthesis50%
Defence against disease47%
Neural signalling46%
Populations and communities46%
Integration of body systems45%
Cell respiration44%

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