Solar tracking, or is a plant's growth toward light. phototropism geotropism hydrotropism thigmotropism

Solar tracking or phototropism refers to the plant’s growth in response to light. It most occur in plants but can also happen in fungi organisms. Auxin is the chemical that reacts to this process and they are found farthest from the light source. Due to this plants tend to have elongated cells that respond to external stimuli. There are two types of this phenomena and they are positive phototropism (growth towards the light) and negative phototropism (growth away from the light). 

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