Question

Snapdragons are incompletely dominant for color. They have phenotypes; red, white, or pink. Red flowers are homozygous dominant, white flowers are homozygous recessive, and pink flowers are heterozygous. What are the genotype and phenotype ratios for a pink female and a white male?

Answer 1

The cross between a pink snapdragon (CRCW) and a white snapdragon (CWCW) results in a 1:1 genotypic ratio (CRCW:CWCW) and a 1:1 phenotypic ratio (pink:white) due to incomplete dominance.

Step-by-step explanation:

In snapdragons, flower color is an example of incomplete dominance, where the heterozygote phenotype is intermediate between the two homozygote parents. For the cross between a pink snapdragon (heterozygote with genotype CRCW) and a white snapdragon (homozygous recessive with genotype CWCW), the offspring genotypes and phenotypes can be predicted. Using the Punnett square, we find the following ratios:

• Genotypic ratio: 1 CRCW : 1 CWCW
• Phenotypic ratio: 1 pink : 1 white

These ratios indicate that 50% of the offspring will be pink (CRCW) and 50% will be white (CWCW).