All genes located on the same chromosome:
a. Form different groups depending upon their relative distance
b. Form one linkage group
c. Will not from any linkage groups
d. Form interactive groups that affect the phenotype
The answer is the option (b) Form one linkage group
Explanation: Closer genes are more likely to form linkages, as the linkage is decided by the vicinity of two genes. Morgan showed that genes form one linkage group when they are located on the same chromosome. Thus, (b) is the answer.