Plant Breath

find where a plant hides its nostrils.

 

 

 

Category - Living Things

Key Idea - Leaves

 

Purpose - To show where a plants breathing holes (stomata) are located
Nature -  Demonstration
Materials -  beaker of very hot water, leaf, forceps or tongs
Method - 
  1. Using the forceps, plunge the leaf into the hot water
  2. Note the formation of tiny little bubbles all over the underside of the leaf.  The top has none of these bubbles.
Safety - Care needs to be take with hot water around children
Explanation - When the leaf is plunged into the hot water, the air in the air-spaces inside the leaf expands.  It comes out through the small holes (stomata) in the leafs surface creating small air bubbles.
Notes - The leaves that work best for this are those that have a very thick waxy coating. This indoor plants of the ficus group work well.

The stomata are located underneath the leaf for a number of reasons.  Firstly it is shady under there, rather than in the full sun on top, and this helps to reduce water loss through the stomata by evaporation.  Secondly, by having the stomata underneath, they are less likely to become clogged with rain water stopping the plant from breathing.