Question

Cross between parents heterozygous for a character with incomplete dominance is expected to give a phenotypic ratio of:

1) 1:1
2) 3:1
3) 9:3:3:1
4) uniform progeny
5) 1:2:1

Answer 1

A cross between parents heterozygous for a character with incomplete dominance is expected to give a phenotypic ratio of 1:2:1. This ratio occurs because in incomplete dominance, neither allele is completely dominant over the other, resulting in a blend of the two phenotypes in heterozygous individuals.

Step-by-step explanation:

A cross between parents heterozygous for a character with incomplete dominance is expected to give a phenotypic ratio of 1:2:1. This ratio represents the proportions of the different phenotypes that will be observed in the offspring.

For example, if the parents have the genotypes Rr and Rr, where R represents the dominant allele and r represents the recessive allele, the phenotypic ratio would be one-quarter with the dominant phenotype (RR), two-quarters with the intermediate phenotype (Rr), and one-quarter with the recessive phenotype (rr).

This ratio occurs because in incomplete dominance, neither allele is completely dominant over the other, resulting in a blend of the two phenotypes in heterozygous individuals.