Final answer:
Incomplete dominance is a pattern of inheritance where the heterozygous genotype results in an intermediate phenotype, as seen in the pink flowers of snapdragons crossed between red and white varieties. It allows for predicting genotype from phenotype and affects various traits across species.
Step-by-step explanation:
Incomplete dominance, also known as partial dominance, is a genetic phenomenon where neither allele is completely dominant over the other in a heterozygous genotype. This results in an intermediate phenotype that is a blend of the phenotypes seen in the homozygous forms of the alleles. The concept was discovered by Karl Correns and is exemplified by the flower color in snapdragons. When a red snapdragon (CRCR) is crossed with a white snapdragon (CWCW), the offspring (F1 hybrids) are pink (CRCW), which is an intermediate color. When two of these pink snapdragons are crossed, they can produce red, pink, and white flowers in a 1:2:1 phenotype ratio, different from the typical 3:1 ratio seen in cases of complete dominance. This pattern allows for the genotype of an organism with incomplete dominance to be inferred directly from its phenotype.
In humans, incomplete dominance can be observed in the gene that determines hair texture. An individual with one curly hair allele (incompletely dominant) and one straight hair allele will have wavy hair. This demonstrates how incomplete dominance can affect a variety of traits in different species.
Learn more about Incomplete Dominance