Final answer:
Centromere linkage in genetics refers to alleles near the centromere on the same chromosome being inherited together, with their likelihood of separation via crossing-over being inversely related to their proximity.
Step-by-step explanation:
In genetics, the term centromere linkage refers to the phenomenon in which alleles located close to the centromere on the same chromosome are genetically linked. This means that these alleles are more likely to be inherited together because they tend to be transmitted through meiosis as a unit unless crossing-over occurs. Crossing-over is the exchange of genetic material between homologous chromosomes, but the closer two genes are to each other and to the centromere, the less likely they will be separated by this process. Therefore, the proportion of recombinant gametes (those not resembling the parental genotypes) produced is a measure of the genetic distance between linked genes and is used to construct linkage maps. When two genes are closely linked, classical Mendelian ratios, such as the 9:3:3:1 ratio expected from a dihybrid cross, do not apply because recombination between the genes is less frequent than it would be if the genes were unlinked or farther apart.