Describe internal factors affecting transpiration.
Internal factors affecting transpiration :

1.Surface area of leaf - Leves having larger surface are have more transpiration. 

2.Thickness of cuticle - Thick cuticle layer lowers the rate of transpiration. 

3. Number of stomata - more the number of transpiration more will be the transpiration. 

4. Sunken stomata - lowers the rate of transpiration.