Question

One pure breeding line of snapdragons has red flowers, another has white flowers. If the hybrid offspring of a cross between these lines has pink flowers, the flower color alleles show______________.

- complete dominance
- co-dominance
- incomplete dominance
- recessiveness

Answer 1

incomplete dominance. The flower color alleles in the hybrid offspring of snapdragons with red and white flowers, which have pink flowers, demonstrate incomplete dominance.

Step-by-step explanation:

If a pure breeding line of snapdragons with red flowers is crossed with another having white flowers, resulting in hybrids with pink flowers, the flower color alleles show incomplete dominance. Incomplete dominance occurs when the phenotype of the heterozygotes is an intermediate of both parents' phenotypes. Neither allele is completely dominant over the other, so the heterozygote expresses a blend of the two, in this case, pink flowers from a mix of red and white alleles.

The flower color alleles in the snapdragons show incomplete dominance.

Incomplete dominance is a pattern of inheritance where the heterozygote phenotype appears intermediate between the two homozygotes. In this case, a cross between a pure breeding line with red flowers and a pure breeding line with white flowers produces offspring with pink flowers.

This occurs because the allele for red flowers is incompletely dominant over the allele for white flowers. The pigment produced by the red allele is diluted in the heterozygote, resulting in pink flowers.

Answer 2

In the case of snapdragons with pink flowers as a result of a cross between red and white flowered plants, the flower color alleles show incomplete dominance.

So, the correct answer is option 3.

Step-by-step explanation:

The hybrid offspring of a cross between a pure breeding line of snapdragons with red flowers and another with white flowers, which has pink flowers, demonstrates a pattern of inheritance known as incomplete dominance. In this form of inheritance, neither allele is completely dominant over the other, resulting in a phenotype that is intermediate between the two parent phenotypes. In the case of the snapdragons, the red allele (CR) is not completely dominant over the white allele (CW), resulting in pink flowers in the heterozygote (CRCW).

So, the correct answer is option 3.