Final answer:
The three-point testcross is used to determine the order and distance between three linked genes on the same chromosome.
Step-by-step explanation:
The genetic mapping method used to determine the order and distance between three linked genes on the same chromosome is the three-point testcross. In a three-point testcross, a cross is made between an individual heterozygous for three linked genes and an individual homozygous recessive for all three genes. By analyzing the progeny from this cross, recombination events can be observed, allowing the determination of the gene order and their distances from each other on the chromosome.
Learn more about Genetic mapping method for linked genes on the same chromosome