Hybrid vigour is also called:

**The reasoning** Hybrid vigour is the phenomenon where offspring produced by crossing two genetically different parents (usually from different varieties or breeds) show **superior qualities** compared to either parent. Think of crossing two varieties of maize — the hybrid often grows taller, yields more, and resists diseases better than both parent plants. This phenomenon has a specific scientific name: **Heterosis**. The term comes from "hetero" (different) + "osis" (condition), literally meaning "the condition of being different/mixed." When you combine the best genes from two different lines, you often get offspring that outperform both parents in growth, fertility, or productivity. **Why the wrong options tempt you** - **Mutation** sounds scientific and involves genetic changes, but it refers to random alterations in DNA, not planned crossing of parents. - **Variation** is too general — it just means differences between organisms, not specifically the superiority of hybrids. - **Selection** is about choosing desirable traits over generations, not the immediate boost hybrids show. **Quick takeaway** When you hear "hybrid vigour" or see offspring performing better than both parents after crossbreeding, immediately think **Heterosis** — it's the only term that specifically names this advantage.