What is the phenotypic ratio in the F2 generation when pink snapdragons are self-pollinated?

What is the phenotypic ratio in the F2 generation when pink snapdragons are self-pollinated?

• A. 1:2:1
• B. 1:1
• C. 2:1
• D. 1:2:2

Answer: (A)

When pink snapdragons are self-pollinated, we're observing a classic example of incomplete dominance, where neither allele is completely dominant over the other. In snapdragons, for instance, the allele for red flowers (denoted as R) and the allele for white flowers (denoted as r) combine to produce pink flowers (genotype Rr). In the F1 generation, crossing a red-flowered (RR) plant with a white-flowered (rr) plant results in all pink-flowered offspring (Rr). When these pink snapdragons are self-pollinated, the genotypes of the F2 generation can be determined using a Punnett square: 1. The possible gametes from Rr (pink) are R and r. 2. The cross results in the following genotypes: - RR (red) - Rr (pink) - rr (white) The frequency of these genotypes in the F2 generation is: - 1 RR (red) - 2 Rr (pink) - 1 rr (white) This gives rise to the phenotypic ratio of 1 red: 2 pink: 1 white, which simplifies to a ratio of

When pink snapdragons are self-pollinated, we're observing a classic example of incomplete dominance, where neither allele is completely dominant over the other. In snapdragons, for instance, the allele for red flowers (denoted as R) and the allele for white flowers (denoted as r) combine to produce pink flowers (genotype Rr).

In the F1 generation, crossing a red-flowered (RR) plant with a white-flowered (rr) plant results in all pink-flowered offspring (Rr). When these pink snapdragons are self-pollinated, the genotypes of the F2 generation can be determined using a Punnett square:

1. The possible gametes from Rr (pink) are R and r.

2. The cross results in the following genotypes:

• RR (red)

• Rr (pink)

• rr (white)

The frequency of these genotypes in the F2 generation is:

• 1 RR (red)

• 2 Rr (pink)

• 1 rr (white)

This gives rise to the phenotypic ratio of 1 red: 2 pink: 1 white, which simplifies to a ratio of