======Gravitropism in Seedling Stalks======


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**Alternative titles:** Seedling Stalk Gravitropism
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====Summary====                   
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====Procedure====  
  - Cut a fresh seedling stalk (hypocotyl).  
  - Attach the stalk to the inside of a film canister lid.  
  - Place the lid back onto the canister so the stalk lies horizontally.  
  - Leave the setup undisturbed for about an hour.  
  - Open the container and observe that the stalk has bent upward, demonstrating negative gravitropism.



====Links==== 
Geotropism - Plants Defying Gravity - Primrose Kitten Academy: 
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📄 Demonstrating Gravitropism in Seedling Stalks - Science & Plants for Schools: [[https://www.saps.org.uk/teaching-resources/resources/184/student-sheet-7-demonstrating-gravitropism-in-seedling-stalks/]]\\


====Variations====
  * Try using seedlings of different ages to see if the rate of bending changes.  
  * Place the canisters at different angles (not just horizontal) to observe varying responses.



====Safety Precautions====
  * Use a clean, sharp blade or scissors when cutting seedlings.  
  * Handle blades with care and cut away from your body.  
  * Dispose of plant material properly after the experiment.




====Questions to Consider====
  * What is negative gravitropism? (It is the upward growth of shoots away from gravity.)  
  * Why do roots grow downward while shoots grow upward? (Roots show positive gravitropism to anchor and seek water; shoots show negative gravitropism to reach light for photosynthesis.)  
  * How do plants sense gravity? (Through statoliths settling in endodermal cells, triggering hormone redistribution.)  
  * Which hormone plays a major role in this response? (Auxin, which redistributes and promotes bending.