(partial dominance) The partial expression of both alleles in a heterozygote so that the phenotype is intermediate between those of the two homozygotes. Thus in Antirrhinum, the homozygotes + + and ww are red and white flowered respectively, while the heterozygote +w is pink. Where one allele is expressed to a greater extent than another, the former may be described as partially dominant. There are all degrees of dominance relationships between complete dominance and incomplete dominance: the dividing lines between the various categories are to some extent arbitrary. See also codominance. |
