Question

In a dihybrid cross, when one pair of alleles show incomplete dominance, genotypic ratios are

• A. 9:3:3:1
• B. 1:2:1
• C. 3:6:3:1:2:1
• D. 1:2:2:4:1:2:1:2:1

Answer 1

The correct option is D 1:2:2:4:1:2:1:2:1

In a dihybrid cross, when one pair of alleles show incomplete dominance, genotypic ratios are the same as that of the Mendelian dihybrid cross which is 1:2:2:4:1:2:1:2:1.
In incomplete dominance, the genotypic ratio never changes, only the phenotype which is intermediate for heterozygous conditions.
In the case of monohybrid cross incomplete dominance, the genotypic and phenotypic ratios are the same which is 1:2:1