The pattern of phenotypic plasticity for a particular genotype. A norm of reaction describes the way in which a genotype is expressed as a trait under different environmental circumstances. For example, for a particular plant genotype that affects height, the norm of reaction in relation to watering level might look like a bell curve: very small and very large amounts of watering result in shorter plants and normal amounts of watering result in taller plants. For plant with a different genotype, the ideal amount of water to grow a tall plant might be different because this genotype might have a different norm of reaction.