Relationship Between Low Heritability and Heterosis
Relationship Between Low Heritability and Heterosis
Traits governed by non-additive gene action (e.g., reproductive traits — fertility, viability, hatchability, litter size) have low heritability. If the heritability of a trait is low, the heterosis will be:
Options
Low
Absent
Medium
High ✓
Correct Answer: D
Explanation in English
Correct Answer: High
From the notes: Traits with low h² show high degree of heterosis, and vice versa.
Logic Behind This Relationship
Low h² means the trait is mainly governed by non-additive gene action (dominance, over-dominance, epistasis)
Non-additive gene action is also the driving force behind heterosis
Therefore, the same traits that respond poorly to selection (low h²) respond well to crossbreeding (high heterosis)
Practical Examples
Reproductive traits (litter size, fertility, hatchability) → low h² → high heterosis → improved by crossbreeding
Carcass traits (fat thickness, dressing %) → high h² → low heterosis → improved by selection
This multiple choice question is from Animal Genetics & Breeding, Animal Refresher. It has 4 options with a detailed explanation of the correct answer. Practice more MCQs from Animal Genetics & Breeding to strengthen your preparation.
