🎴 Flashcard Mode

Phototropic curvature is the result of uneven distribution of auxin. Darwin and Darwin observed that the coleoptiles of canary grass responded w unilateral illumination by growing towards the light source (phototropism). After a series of experiments, It was concluded that the tip of coleoptile contains auxin that caused the bending of the entire coleoptile in relation to the direction of light.