Monohybrid Cross Problem Set

Problem 10: Disappearance of parental phenotypes in the F1 generation

A genetic cross of inbred snapdragons with red flowers with inbred snapdragons with white flowers resulted in F1-hybrid offspring that all had pink flowers. When the F1 plants were self-pollinated, the resulting F2-generation plants had a phenotypic ratio of 1 red: 2 pink: 1 white. The most likely explanation is:

A. pink flower color is epistatic to red flower color.

B. pink flowers are the result of a blending of the red and white genotypes.

C. flower color is due to 2 or more complementary genes.

D. heterozygous plants have a different phenotype than either inbred parent because of incomplete dominance of the dominant allele.

E. flower color inheritance in snapdragons does not behave as a Mendelian trait.

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Thursday, October 1, 1998
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