Question

_________ occurs when 50% of a protein produces a different phenotype than that produced by 100% or 0% of the protein.

A. Incomplete dominance
B. Recessive inheritance
C. Codominance
D. Loss of function mutation
E. Hybridization

Answer 1

Incomplete dominance (option A) is the genetic pattern where the heterozygote exhibits an intermediate phenotype between the homozygous phenotypes, such as pink flowers from red and white snapdragons, or wavy hair from one curly and one straight-haired parent.

Step-by-step explanation:

The situation described occurs in the phenomenon known as incomplete dominance. In this genetic pattern of inheritance, a heterozygous genotype results in a phenotype that is intermediate between the phenotypes of the homozygous parents. Unlike cases of simple dominance where the dominant allele would completely mask the effect of the recessive allele, in incomplete dominance, the presence of only one copy of the dominant allele results in a phenotype that is a blend of the two alleles.

For example, in snapdragons, when a red-flowered plant is crossed with a white-flowered plant, the offspring may have pink flowers—this intermediate color is due to incomplete dominance. Similarly, in humans, the inheritance of hair texture exhibits incomplete dominance with the combination of one curly hair allele (dominant) and one straight-hair allele (recessive) resulting in wavy hair.