Cambridge O Level Biology · Syllabus 5090 · Coordination and Response in Plants
Positive Phototropism
What is Positive Phototropism?
The growth of a plant organ toward light. In a shoot lit from one side, auxin becomes unequally distributed with more present on the shaded side; auxin stimulates cell elongation, so cells on the shaded side elongate more, that side becomes longer, and the shoot bends toward the light.
This definition is part of the Coordination and Response in Plants chapter in Cambridge O Level Biology.
Last reviewed Syllabus 2026-2028