Final answer:
In a cross between two heterozygous organisms showing incomplete dominance, the genotypic ratio is typically 1:2:1, which means 1 AA, 2 Aa, and 1 aa in the offspring.
Step-by-step explanation:
When you cross two organisms that are both heterozygous for a gene showing incomplete dominance, the expected genotypic ratio in the offspring is 1:2:1. This ratio comes from the classic Mendelian genetics Punnett square where each heterozygous parent (Aa) can contribute either an A or an a allele, leading to the following possible combinations: AA, Aa, aA, and aa. However, because Aa and aA are the same genotype, they are combined for the ratio, which is then 1 AA : 2 Aa : 1 aa. The phenotype ratio, on the other hand, would depend on how the traits are expressed in the particular organism.