what is tropism and nastics ?

Asked by  | 1st Sep, 2012, 01:31: PM

Expert Answer:

Tropism is the response of an organism, esp a plant, to an external stimulus by growth in a direction determined by the stimulus. The plant part may turn or bend towards or away from an external stimulus, such as light, heat, or gravity.
 
Nastic responses are rapid, reversible responses to non-directional stimuli (such as temperature, humidity, light intensity). The rate or frequency of these responses increases as intensity of the stimuli increases. Example - The opening and closing of flowers.

Answered by  | 3rd Sep, 2012, 07:43: AM

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