College

What is the complex inheritance pattern, and how can you justify it using evidence from a Punnett square with genotypes Dd and ll?

The Punnett square provides the following combinations: Dl, Dl, dl, dl.

Answer :

The complex inheritance pattern observed in the Punnett square is incomplete dominance.

Incomplete dominance occurs when neither allele is completely dominant over the other, resulting in an intermediate phenotype in heterozygous individuals. In this case, the Punnett square shows that the genotype Dd (where D represents one allele and d represents the other allele) results in a phenotype that is intermediate between the phenotypes of the homozygous dominant genotype (DD) and the homozygous recessive genotype (dd).

In the given Punnett square, the genotypes Dl and dl both result in the same intermediate phenotype, indicating incomplete dominance. This suggests that neither the D allele nor the d allele is completely dominant over the other, resulting in a blending of traits in heterozygous individuals.

Evidence from the Punnett square:

- When the genotype Dd is crossed with ll, the resulting genotypes are Dl and dl.

- Both Dl and dl exhibit the same intermediate phenotype, indicating that neither the D allele nor the d allele is completely dominant over the other.

- This supports the concept of incomplete dominance, where the heterozygous genotype results in an intermediate phenotype that is a blend of the two homozygous phenotypes.

Therefore, based on the Punnett square results, the observed inheritance pattern is incomplete dominance.