Question : To observe the response of plant parts to light OR To study phototropism in plants. Materials : Conical flask, wire mesh, cardboard box open from one side, water, two- three freshly germinated bean seeds. Procedure : rarr Fill a conical flask with water. rarr Cover the neck of the flask with a wire mesh. rarr Keep two-three freshly germinated bean seeds on the wire mesh. rarr Take a cardboard box which is open from one side. rarr Keep the flask in the box in such a manner that the open side of the box faces light coming from a window. rarr Observe after two or three days and note down your observation. rarr Now turn the flask and leave it undisturbed in this condition for a few days and then observe. Observation : In the initial position of flask, the shoot bends towards light and roots turn away from light. rarr After turning the flask, position of shoot and roots change, i.e., shoot goes away from light and roots turn towards light but after a few days shoot again shows bending towards light and roots move away from light. What can we conclude from this activity ?