When dominant and recessive alleles express themselves together it is called : -
A
Co-dominance
B
Dominance
C
Amphidominance
D
Pseudo dominance
The answer is A.
Solution
In co-dominance, both alleles of a gene express themselves fully in the heterozygote; neither masks the other. Example: in the ABO blood group, $I^A$ and $I^B$ are both expressed in $I^AI^B$ (blood group AB); in cattle, red and white give roan. In dominance only the dominant allele is expressed, and in incomplete dominance the heterozygote is intermediate. So when both alleles express themselves together, it is called co-dominance.
ConceptBoth alleles expressed in heterozygote
Principles of Inheritance and Variation in past papers
198 questions from this chapter have appeared across 27 exam years.
