Subjective and Short Questions For Plant Movements


  1. Write a note on tropic movements.
    1. Write note phototrapism,Give its mechanism.
    2. Write note on geotropism. Give its mechanism.
    3. Write note on nastic novement.


Differentiate between autonomic and Paratonic movements.

Ans: The movements induced by some internal causes are called autonomic movement. The movement induced by external stimuli is called Paratonic movement.

  1. What is phototropism? How is it caused?

Ans: The tropic movement of the part of plant in response to stimulus of light is called phototropism. It is caused due to differential growth of part of plant like root, stem or root.

  1. What is meant by diaphototropic?

Ans     Leaves also show response to light. They twist their petioles and place their faces (upper sides) at right angles to the light. They are diaphototropic or transversely phototropic.

  1. What is Cholodny and Went theory of phototropism?
  2. Ans: Cholodny and Went theory suggested that the phototropic response occur due to unequal distribution of auxin (IAA).

5         What is Cholodny and Went theory of geotropism?



Ans:     This theory suggests that differential growth in geotropism is caused due to unequal distribution of auxin (IAA) in the upper and lower halves of the shoot.

  1. What are Seismonastic movements?

Ans: The shock movements are called Seismonastic. It occurs in mimosa. When. the leaves of Mimosa (touch me not) is touched. the leaflet fold together. This response takes one or t%%6 seconds.

  1. What are Haptonastic movements?

Ans     The nastic movement occurs due to stimulus of touch are called Haptonastic movements. I laptonastic movements occur in the leaves of Drosera and Dionaea.

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