|Complete Dominance||Incomplete Dominance|
|F1 is similar to dominant parent.||F1 is different from either of the two parents.|
|Phenotypic ratio = 3 : 1||Phenotypic ratio = 1 : 2 : 1|
Genotypic ratio = 1 : 2 : 1
|Phenotypic ratio ≠ Genotypic ratio||Phenotypic ratio = Genotypic ratio|
|In F1 dominant trait expresses fully||In F1 dominant trait is incompletely expressed|
|One dominant allele is enough to express dominant trait||Two alleles are required to fully express dominant trait|
Humans (Hairy is dominant over Baldness);
Blood group Allele A is dominant over blood group O
Snapdragon - Antirrhinum Majus
Gene InteractionsBoth the Complete and Incomplete Dominance are the Intragenic (Allelic) Gene Interaction. The other types are:
- Intragenic (Allelic) Gene Interaction
- Complete Dominance
- Incomplete Dominance
- Multiple Alleles
- Lethal Genes
- Intergenic (Non-Allelic) Gene Interaction
- Duplicate Genes
- Complementary Genes
- Supplementary Genes
- Polymeric Genes
- Polygenic Genes
Incomplete DominanceIn the case of Incomplete Dominance, dominant allele do not completely express itself, resulting in a different phenotype. F1 generation expresses a phenotype which is intermediate between those of the parent.
Carl Correns discovered incomplete dominance and cytoplasmic dominance.
Definition of Incomplete DominanceIncomplete dominance is a type of Gene interaction, in which, in a heterozygous condition, both alleles of a gene at a locus are partially expressed, often resulting in an intermediate (or different) phenotype. It is also called partial dominance.
Complete DominanceIn the case of Complete Dominance, dominant allele completely express itself, thereby masking the effect of Recessive allele, resulting in a dominant phenotype. F1 generation expresses a phenotype which is dominant between the parents.
Definition of Complete DominanceComplete dominance is a type of Gene interaction, in which, in a heterozygous condition, the dominant allele of a gene at a locus is fully expressed, supressing the recessive allele, resulting in a dominant phenotype.
Multiple Choice Questions
In F2 generation, we observe the phenotypic ratio = 3 : 1. Which of the following conclusion would be correct? (1) Trait = 2, Dominance = Complete (2) Trait = 1, Dominance = Incomplete (3) Trait = 1, Dominance = Complete (4) Trait = 2, Dominance = Incomplete Ans: http://zoomgenetics.apphb.com/?id=m39
In F2 generation, we observe the phenotypic ratio = 1 : 2 : 1. Which of the following conclusion would be correct? (1) Trait = 2, Dominance = Complete (2) Trait = 1, Dominance = Incomplete (3) Trait = 1, Dominance = Complete (4) Trait = 2, Dominance = Incomplete Ans: http://zoomgenetics.apphb.com/?id=m40
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