Please note that:
1) This description of two-point mapping ignores the possibility of double-crossovers (or higher-order crossovers) occurring
2) I made a mistake at the end of the video when summing the numbers of recombinant types: I switched the totals of the B-C and A-C columns. The real calculation of recombinants for B-C is 261, and for A-C is 482. Thus, the genetic distances that should be calculated are: A-B (19.92 cM), B-C (21.75 cM), and A-C (40.16 cM).
00:00 Introduction; review of two-point genetic mapping
00:48 Three-point mapping calculates three genetic distances at once
05:48 Experimental analysis of F2 generation data
07:19 Identifying the recombinant haplotypes
11:36 Calculating individual interval genetic distances (A-B, A-C, B-C)
14:43 For the next class
![](https://s2.save4k.ru/pic/HdIBRYvDUzM/maxresdefault.jpg)