Question

Red-flowered snapdragons are crossed with white-flowered snapdragons, producing all pink snapdragons in the F1 generation. What would you expect if you crossed pink with pink? The choices are... (1/2, 1/4, 3/4) red, (1/2, 1/4, 3/4) pink, (1/2, 1/4, 3/4) white.

Answer 1

Answer:

Red (1/4), Pink (1/2), white (1/4)

Explanation:

This question involves a single gene coding for flower colour in the snapdragon plants. The gene exhibits incomplete dominance, because the allele for red color (R) is incompletely dominant over the allele for white color (W), hence an intermediate phenotype is produced as pink color (RW).

The pink colored snapdragon plant is produced in the F1 generation. When these F1 offsprings are crossed i.e. RW (pink) × RW (pink), gametes with R and W alleles are produced by each F1 parent.

Using these gametes in a punnet square (see attached image), four possible offsprings with genotypes; RR, RW, RW and WW will be produced in the F2 generation.

RR offsprings (1/4)- Red flowered

RW offsprings (2/4 or 1/2)- Pink flowered

WW offsprings (1/4)- White flowered