We all see the shrinking of leaves in touch me not plant (Chui-Mui) in response to touch or air.Plant shrink its leaves and the stem droop in response to touch.This happens due to changes in the turgor pressure.
Plant hormones are the chemicals produced in a plant which regulate its various activity like growth, ripening, fruit development. We also call them phytohormones and growth regulator as they regulate the growth of the plant.
Our body responds to changes in the environment without even thinking of it. We term this reflex action. Here the peripheral nervous system (spinal cord) of the brain responds to changes and do the action with minimal time.
Agarbatti or incense stick on burning produces fragrance. These fragrances reach to olfactory bulb through the nose.The olfactory bulb is a chemosensory organ. It detects the presence of chemicals present in the air