Final answer:
In a dihybrid cross with linked genes, parental genotypes are more common than recombinant genotypes, but crossover events can create recombinant gametes. The frequency of these recombinant gametes informs the construction of linkage maps. Double crossover events increase genetic diversity by producing novel allelic combinations.
Step-by-step explanation:
When two genes are located in close proximity on the same chromosome, they demonstrate genetic linkage and their alleles are more likely to be transmitted through meiosis together. In a dihybrid cross involving linked genes, such as those affecting flower color and plant height, parental genotypes are more common among the gametes than recombinant genotypes. However, crossover events can occur, leading to recombinant gametes. The rate of these crossover events between two genes can be used to map their distance on a chromosome.
During meiosis, if there is a double crossover between the genes of interest, two of the resulting chromosomes will be recombinant with gene combinations that differ from either parent. The proportion of these recombinant offspring provides data for constructing linkage maps, which are diagrams illustrating the relative locations of genes on a chromosome. For example, if 17% of the offspring are recombinant, this indicates that the genes are on the same chromosome but that crossover occurs occasionally.