1. The problem statement, all variables and given/known data In linkage strength between any two gene loci is 70%,what would be the amount of crossing over between these loci? (a) 15% (b)30% (c) 70% (d) none of these. 2. My approach at understanding the concept I didn't find much about linkage strength from any authentic source. I can think of two things : The strength of a linkage would be greater if the spatial separation between two genes is less and the lesser if the separation is more. This is semantic. But, how can it be represented in percentage? What does this 100 mean in this 70%? The separation between two genes can be more than 100 map units. 3. Question in details What does linkage strength mean? How is it related to amount of crossing over? I would appreciate answers citing some authentic sources.