What is the reaction rate? What determines the limit of variation of a trait? Give examples of signs with different reaction rates.

The reaction rate is the limit of the modification variability of the trait, due to the genotype. Qualitative characteristics, such as the color of animal hair and plant flower, have a narrow limit of variability, since they are vital (animal color plays a protective role, the colored corolla of the flower attracts pollinating insects). Quantitative traits, such as the mass of the animal, the size of the leaves of the plant, vary over a fairly wide range. However, quantitative traits such as the size of the heart and brain have a narrow reaction rate. The reaction rate is expressed as a variation series or as a variation curve.