Final answer:
Hybrid vigor or heterosis refers to the superiority of a hybrid over its inbred parents in certain traits. This concept arises from Mendel's genetic studies where dominant traits are expressed in hybrids, while recessive traits can reappear in further generations.
Step-by-step explanation:
The superiority of a hybrid over either inbred parent with respect to one or more traits is called hybrid vigor or heterosis. In the context of Mendelian genetics, Gregor Mendel found dominant traits are those that are expressed in a hybrid offspring, while recessive traits may not be expressed in the hybrid but can reappear in subsequent generations.
An example of this is when Mendel crossed purebred yellow and green pea plants; the offspring were all yellow (dominant) even though the green trait (recessive) reemerged in the progeny of the hybrids. Additionally, Mendel's work laid the foundation for understanding non-Mendelian inheritance patterns, such as incomplete dominance, where the hybrid shows an intermediate trait, like the pink flowers in a cross between red and white snapdragons.