Tactic movements in plant


 The movement by which an entire cell or organisms change their position in response to external stimuli.
The movement will be positive if organism moves towards the stimulus.
It is negative if organism move away from the stimulus.
Tactic movement are dived into further kinds on the basis of the nature of the stimulus.

  •  Phototactic Movements 
  • Chemotactic Movements

(i) Phototactic Movements: The tactic movement in response to stimulus of light is called phototactic movement.

Example: The movement of chloroplast due to cyclosis (movement of cytoplasm within cells) is the best example of positive tactic movement.
It is the passive movement of chloroplast. In this way, chloroplast absorbs maximum light for CO₂ fixation.
The direction of light and intensity of light both effect the intracellular distribution of chloroplast.

(ii) Chemotactic Movement: The tactic movements in response to stimulus of chemical is known as chemotactic movement.

Example: Sperms of liverworts, mosses and ferns toward archegonia in response to stimulus of nucleic acid.
Nucleic acid is released by the ovum.

Tactic movements in plant Tactic movements in plant Reviewed by SaQLaiN HaShMi on 9:26 PM Rating: 5

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