Genetic Basis of Polygenic Inheritance
Polygenic inheritance, general combining ability & resemblance between relative is due to-
- Additive Gene action — Correct Answer
- Non-Additive Gene action
- Both
- None
Explanation:
Correct Answer: Additive Gene Action
Polygenic inheritance, General Combining Ability (GCA), and resemblance between relatives are all due to Additive Gene Action (AGA).
Additive vs Non-Additive Gene Action
| Index | Additive Gene Action (AGA) | Non-Additive Gene Action (NAGA) |
|---|---|---|
| Also called | Allelic interaction (within locus) | Non-allelic / Intergenic interaction |
| Examples | Dominance, Co-dominance, Incomplete dominance, Over-dominance | Epistasis and its forms |
| Used for | Polygenic inheritance, GCA, Resemblance between relatives, Selection | Heterosis, SCA, Cross-breeding |
| Fixable by selection? | Yes | No — lost after F₁ |
Types of Gene Action Diagram
- AGA → Allelic Interaction (Dominance, Co-dominance, Incomplete dominance, Over-dominance)
- NAGA → Non-allelic Interaction (Epistasis: Complementary, Duplicate, Inhibitory, Dominant, Recessive)
📚 About this Topic — Animal Genetics & Breeding
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.
