Final answer:
The coloration of betta fish offspring resulting in orange from red and yellow parents is an example of incomplete dominance, which is a type of inheritance where the heterozygote shows a blend of parental traits.
Step-by-step explanation:
The color of betta fish when a RED fish (GG) is crossed with a YELLOW fish (gg) producing ORANGE offspring (Gg) is an example of incomplete dominance. Incomplete dominance is a pattern of inheritance in which the heterozygous phenotype is intermediate between both homozygous phenotypes. Neither allele is completely dominant over the other, which results in a mixture of the two parental traits.
This concept differs from codominance, where both alleles in the heterozygote are fully expressed, as seen in the MN blood groups in humans or the snapdragon flowers producing pink offspring from red and white parents. It also varies from polygenic traits, where multiple genes influence the phenotype, and sex-linked genes, where the trait is linked to a sex chromosome.