Answer:
D
Step-by-step explanation:
Incomplete dominance is a phenomenon in genetic inheritance that occurs when the two alleles of a gene seem equally effective in their influence on a trait. It is a form of Intermediate dominance in which one allele for a specific trait does not completely mask the expression of its paired allele, as opposed to Mendel's law of dominance. Incomplete dominance results in a third phenotype different from the parent phenotypes but a combination of both.
In incomplete dominance, the intermediate/resulting phenotype is the heterozygous genotype.
Gregor Mendel discovered this concept of incomplete dominance in the flower of four o'clock plants when he crossed a purebred (homozygous) red-flowered (RR) with a purebred (homozygous) white-flowered plant (rr) to get F1 offsprings that are all heterozygous but have pink flowers (Rr). He later self-fertilized the F1 offsprings to produce a phenotypic ratio of 1:2:1 consisting of 1 red, 2 pinks, 1 white flower respectively.
This showed that the allele for red flower (R) is incompletely dominant over the allele for white flower (r), hence, producing an offspring with a different trait that arose from the blending of the two phenotypes.
Incomplete dominance is similar but different from co-dominance in the sense that, in co-dominance, both alleles/traits are expressed completely in the new phenotype produced while in incomplete dominance, the new phenotype is just a blending of the two phenotypes.