A series of two-point crosses, involving 7 genes (a-g), were carried out, and the following recombination frequencies were obtained. Place the seven genes into linkage groups (where a linkage group is any group of genes that are genetically linked to each other). Within each linkage group, determine the order of genes and the distances between them.
Genes % recombination Genes % recombination
a-b 50 c-d 50
a-c 50 c-e 26
a-d 12 c-f 50
a-e 50 c-g 50
a-f 50 d-e 50
a-g 4 d-f 50
b-c 10 d-g 8
b-d 50 e-f 50
b-e 18 e-g 50
b-f 50 f-g 50
b-g 50