Explore the Fascinating World of Incomplete Dominance in Snapdragons!
Have you ever wondered how flower color is determined in snapdragons?
According to the concept of incomplete dominance, what are the phenotypes of the parents, genotypic ratios in the offspring, and phenotypic ratios in the offspring for different scenarios?
Understanding Incomplete Dominance in Snapdragons:
Snapdragons display the concept of incomplete dominance, where contrasting alleles express an intermediate phenotype. These expressions determine flower color variations from red, pink to white according to different parent genotype combinations.
Explanation:
In the case of snapdragons, the color of the flowers is determined by incomplete dominance. Here, two contrasting alleles express an intermediate phenotype. A perfect demonstration of this is the color variation in snapdragons where the allele for red flowers (CRCR) is incompletely dominant over the allele for white flowers (CWCW), resulting in a pink flower (CRCW) as the intermediate phenotype.
For the four scenarios given:
- Phenotypes of parents: Red x White, namely, CRCR x CWCW. All the progeny would be heterozygotes (CRCW) with pink flowers. Hence, the ratio of genotypes is 1:1, and the ratio of phenotypes would be all pink.
- Phenotypes of parents: Pink x Pink, that is, CRCW x CRCW. The resulting genotypic ratio would be 1 CRCR:2 CRCW:1 CWCW and the phenotypic ratio would be 1 red (CRCR):2 pink (CRCW):1 white (CWCW).
- Phenotypes of parents: Red x Pink, CRCR x CRCW would result. Here, the genotypic ratio is 1:1 (CRCR: CRCW) and the phenotypic ratio is 1 red (CRCR): 1 pink (CRCW).
- Phenotypes of parents: White x White, or, CWCW x CWCW would produce all offspring with genotypes CWCW and phenotypes white.