For linked genes A, B, and C, the map distance A–B is 5 map units and the map distance B–C is 25 map units. If there are 10 double crossover events out of 1000 offspring, what is the interference?

Explanation:

Given:

Distance between A-B = 5 map unit,

Distance between B-C= 25,

The value of coefficient of coincidence is=  0.01/0.0125 = 0.8,  

so the interference is 1 - 0.8 = 0.2.

The positive value of  interference  confirms that the genes are linked, if it value is negative , then shows that the genes are unlinked