Occurring only in response to wavelengths under 500 nanometers, name this type of growth in which auxin stimulates a plant to bend toward a light source.
Charles Darwin studied this phenomenon in oat coleoptiles (koh-lee-OP-tils), and Frits Went used agar blocks to determine that it was not the result of electrochemical impulses. Explained by the acid growth hypothesis, this process begins when indoleacetic (in-dohl-uh-SEE-tihk) acid lowers the pH ("P H") of cell walls, allowing turgor pressure and expansin enzymes to elongate cells. Occurring only in response to wavelengths under 500 nanometers, name this type of growth in which auxin stimulates a plant to bend toward a light source.
Charles Darwin studied this phenomenon in oat coleoptiles (koh-lee-OP-tils), and Frits Went used agar blocks to determine that it was not the result of electrochemical impulses.
{phototropism} [accept word forms; prompt on {tropism} or word forms {thereof}]