RRB Non Technical Model Papers 7 with solutions

(4) Plants need light and water for photosynthesis. They have developed responsed called tropism to help make sure they grow towards source of light and water. There are different type of tropism :
● Phototropism - growth in response to the direction of light.
●Geotropism - growth in response to the direction of gravity.
●Positive tropism - towards the stimulus
● Negative tropism - away from the stimulus
●Auxin is a plant hormone responsible for controlling the direction of growth of root tips and stem tips in response to different stimuli including light and gravity.