Written by the Fiveable Content Team • Last updated September 2025
Verified for the 2026 exam
Verified for the 2026 exam•Written by the Fiveable Content Team • Last updated September 2025
Definition
Phototropism is the growth or movement of a plant in response to light direction.
Related terms
Auxin: A hormone that plays a key role in phototropism by promoting cell elongation on the dark side of the plant, causing it to bend towards light.
Heliotropism: The directional growth of a plant in response to sunlight, but unlike phototropism, this involves the entire plant moving rather than just growing in one direction.