Distance between the genes a, b, c and d in map units is a−d=3.5,b−c=1,a−b=6,c−d=1.5 and a−c=5. Find out the sequence of the genes.
If (a + b +c + d) (a -b- c+ d)
=(a + b- c- d) (a -b+c- d);
prove that : a : b =c : d.