BIOL-UA 12 Lecture Notes - Lecture 21: Absorbance, List Of Magical Girl Lyrical Nanoha Characters, Systemic Acquired Resistance
31 May 2016
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Lecture 21: plant signaling: stem cell niches in animals: drosophila germ line, hematopoietic cells, responses to signals: Plants respond to external signals and are mediated by internal signals. Plants respond to pathogens by producing chemicals (plant hormones) that can kill animals that eat them. Most of our medicines come from plants, as low doses of these compounds can be bene cial: phototropism: Darwin grew corn coleoptiles and they grew towards the light. Darwin wanted to nd which part of the plant perceives the light signal. He cut the tip of one coleoptile, covered the tip of another with opaque foil, covered the third with transparent lm and covered the base of the last one. The rst two did not bend towards the light, the other two did. Darwin wanted to nd is the signal is mobile: one coleoptile tip was separated from the rest by a gelatin block, which allowed hormone/signal diffusion.
