BIOLOGY 1AL Lecture Notes - Lecture 17: Plant Hormone, Coleoptile, Phototropism
Document Summary
Phototropism = movement in response to light (egg fungi discussed earlier in lecture) Interested in phototropism of grass seedlings: coleoptile, gave coleoptile light form one direction, found that it bended toward light. They asked what part of the coleoptile receives the light: determined it was the tip of coleoptile which perceived light, if you cover tip and illuminate -> no bending. Tip was omen way signaling the religion of coleoptile, which will show differential growth. Substance produced in coleoptile was responsively for bending. Found out that: substance was produced in the tip. Move downward where it stimulated growth: when black symmetrical (in dark) he substance moved downwardly, when block was asymmetrical, non-uniform distribution. In the light (unidirectional light) there was more substance eon the dark side (away from the light) compared to side closest to light. This difference in substance mat -> differential growth.
