You are growing a Chrysanthemum plant in an artificial growth chamber in a florist shop. You want to induce the plant to flower, so since this is a "fall" plant, you grow it in 1. _______________. By accident, a night-watchman checking the facility turns a flash-light on in the growth chamber in the middle of the night. This short pulse of white light activates 2. _______________, which interrupts the 3. ___________ that controls flowering, and thus the plant 4. _________________.