What does hybrid vigor refer to?

• A. The decrease in fitness in hybrid offspring
• B. The enhanced traits in offspring from diverse parents
• C. The genetic uniformity of hybrid seedlings
• D. The isolation of purebred traits in offspring

Answer: (B)

Hybrid vigor, also known as heterosis, refers to the phenomenon where hybrid offspring exhibit enhanced traits compared to their parents. This can include improvements in growth rate, fertility, resistance to disease, and overall vigor. The concept arises from the combination of diverse genetic backgrounds in the parent organisms, which leads to greater genetic variation in the offspring. This genetic diversity often allows hybrids to perform better under various environmental conditions and to exhibit more resilience than their purebred counterparts.

In breeding practices, hybrid vigor is a sought-after trait because it can significantly improve agricultural yields and the health of populations. This illustrates why the correct choice highlights enhanced traits in offspring from diverse parents, showcasing the advantages of combining genetic materials from two distinct lineages in a way that promotes superior characteristics.