How is incomplete dominance different than dominance?
Explain why incomplete dominance only occurs in this genotype?
My school doesn't give us books!!
http://www.google.com/#q=incomplete+dominance+different+than+dominance
Incomplete dominance is a type of inheritance pattern where neither of the two alleles in a heterozygous individual completely dominates the other. In other words, when an individual carries two different alleles for a particular trait, the phenotypic expression of the trait will be a blend or intermediate of the two alleles.
Dominance, on the other hand, is a pattern where one allele masks or overrides the expression of the other allele in a heterozygous individual. In the case of complete dominance, only the dominant allele is expressed phenotypically, while the recessive allele remains hidden.
To understand why incomplete dominance occurs only in certain genotypes, we need to examine the underlying mechanisms at the molecular level. Incomplete dominance often involves a situation where the alleles at a specific locus do not produce identical or functional proteins.
For fully dominant traits, the dominant allele produces a functional protein that determines the trait's expression. Meanwhile, the recessive allele typically produces a non-functional or significantly altered protein that cannot contribute to the phenotype.
In the case of incomplete dominance, neither allele is fully functional, resulting in an intermediate phenotype. This occurs when the proteins produced by the two alleles interact in a way that modifies the trait's expression.
Therefore, incomplete dominance only occurs when both alleles produce partially functional proteins that can interact and produce a blended or intermediate phenotype. If either allele produces a non-functional protein that cannot interact with the other allele, then complete dominance or recessiveness will be observed instead.