Flower color in snapdragons is an example of incomplete dominance. When a red-flowered plant is crossed with a white-flowered plant, the F₁ generation has pink flowers. If a pink-flowered plant is crossed with another pink-flowered plant, the progeny plants will be __________.

• A. 100% pink
• B. 100% red
• C. 50% pink and 50% red
• D. 25% white and 75% red
• E. 25% red, 50% pink, and 25% white

Answer: (E)

Verified step by step guidance

1. Understand the concept of incomplete dominance: In incomplete dominance, the heterozygous phenotype is a blend of the two homozygous phenotypes. In this case, red (RR) and white (WW) flowers produce pink (RW) flowers.
2. Identify the genotypes of the parent plants: Since both parent plants are pink, their genotype is RW.
3. Set up a Punnett square: Place one parent's alleles (R and W) on the top and the other parent's alleles (R and W) on the side of the square.
4. Fill in the Punnett square: Combine the alleles from each parent to fill in the four squares, resulting in the genotypes: RR, RW, RW, and WW.
5. Determine the phenotypic ratio: Count the genotypes to find the phenotypic ratio. RR results in red flowers, RW results in pink flowers, and WW results in white flowers. The ratio is 1 red (25%), 2 pink (50%), and 1 white (25%).