Folding of leaves in the mimosa plant and growth of plant towards light are examples of tropic movements. Do you agree? Why or why not?
Folding of leaves in the mimosa plant and growth of plant towards light are examples of tropic movements. Do you agree? Why or why not?
Recall the knowledge of phytohormones. Auxin is the hormone which shows cell enlargement and cell division. When a plant is subjected to the above mentioned condition, due to the direct sunlight on one side the auxin synthesis increases which enhances the growth of stem on the other side thereby bending the plant towards light, which we call “plant movement”. Plant movement is broadly studied under following two heads.
- Tropism or Tropic movement
- Nasties or Nastic movement
Tropism or Tropic movements Tropic movement is the directional movement of the part of plant in response to external stimuli. The direction of response is determined by the direction of stimulus. The direction of movement of plant can be towards the stimulus i.e. positive tropism or can be away from the stimulus. i.e. negative tropism.
Nastic movement can be defined as, “the movement of plant part in response to an external stimuli in which the direction of response is not determined by the direction of stimulus“. It is usually shown by flat structure of plant such as leaf.
One of the best studied example of nastic movement is “response of Mimosa pudica on touch“.
Nastic movement may or may not be growth movement. The opening of flower by the action of sun light is a growth phenomenon where as folding of leaf on touch as in case of Mimosa pudica is not a growth phenomenon.
Plant movement is broadly studied under following two heads.
- Tropism or Tropic movement
- Nasties or Nastic movement
Tropic movement is the directional movement of the part of plant in response to external stimuli. The direction of response is determined by the direction of stimulus. The direction of movement of plant can be towards the stimulus i.e. positive tropism or can be away from the stimulus. i.e. negative tropism.
Nastic movement can be defined as, “the movement of plant part in response to an external stimuli in which the direction of response is not determined by the direction of stimulus“. It is usually shown by flat structure of plant such as leaf.
One of the best studied example of nastic movement is “response of Mimosa pudica on touch“.
Nastic movement may or may not be growth movement. The opening of flower by the action of sun light is a growth phenomenon where as folding of leaf on touch as in case of Mimosa pudica is not a growth phenomenon.
