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Could someone help me in my project?It is about 7 nastic movements with two examples...

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rahulsk | Student, Grade 10 | (Level 1) Honors

Posted August 18, 2013 at 11:12 AM via web

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Could someone help me in my project?

It is about 7 nastic movements with two examples each.

1. Photonasty

2. Nyctinasty

3. Chemonasty

4. Hydronasty

5. Thermonasty

6. Geonasty

7. Thigmonasty

I need it urgently by tomorrow

Thanks

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mvcdc | Student, Graduate | (Level 1) Associate Educator

Posted August 18, 2013 at 11:51 AM (Answer #1)

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Nastic movements are responses (usually of but not limited to plants) to stimuli. Unlike trophisms, these are not dependent on the direction of the stimulus.

  • Photonasty - response to light. Examples: Vertical growth of plants towards light source; Change in orientation of cannabis leaves (from horizontal to vertical) during sun down.
  • Nyctinasty - reponse to dark, or night. Examples: Closing/Opening of daisies and cloves at night/morning; Sleep movements of the leaves of legumes.
  • Chemonasty - response to chemical stimulus. Examples: Closing/Bending of glandular hairs of sundew in response to nitrogenous compounds from an insect to prevent the escape of such insect; Movement of roots towards the more nutrient-rich parts of the soil.
  • Hydronasty - response to water. Examples: Movement of roots towards water source, like near the river; Opening/Closing of dandelions in response to humidity (water in the atmosphere).
  • Thermonasty - response to temperature. Examples: Opening of tulips when the temperature is increasing and closing when temperature is decreasing, which serves to protect pollens when snow/rain falls; Growth of tomatoes is better when temperature is alternating (night/day) than when temperature is kept constant (all night / all day).
  • Geonasty - response to gravity. Examples: Bending of long leaves or barks (when the strength of the plant is not enough to support them against gravity); The upward growth of a plant (against gravity) and generally downward movement of roots (with gravity).
  • Thigmonasty - response to contact. Examples: Closing of Mimosa pudica(also known as the touch-me-not plant) in response to touch/contact; Closing of the venus fly trap in response to movement, usually due to landing of insects, to capture the insect.

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