What characteristic do snapdragons exhibit as a model for incomplete dominance?

• A. All offspring are identical
• B. Offspring show traits from both parents
• C. Only one parent's trait is expressed
• D. Traits are always fully dominant

Answer: (B)

Snapdragons provide an excellent example of incomplete dominance, where the offspring display a phenotype that is a blend of the traits from both parents. In the case of snapdragons, when a red-flowered plant is crossed with a white-flowered plant, the resulting offspring exhibit pink flowers. This blending occurs because neither parent’s allele is completely dominant over the other, leading to a phenotype that reflects an intermediate expression of both alleles.

This phenomenon highlights the essence of incomplete dominance: the expression of both parental traits in a way that creates a new, distinct phenotype. Rather than showing traits that are identical, exclusive to one parent, or fully dominant, the offspring embody a combination of characteristics, thus illustrating the principle of incomplete dominance effectively.